The Form Class# and the .NET Platform, Second Edition

This brings us to the Form class itself, which is typically the direct base class for your custom Form types. In

Apress © 2003 (1200 pages)

addition to the large set of members inherited from the Control, ScrollableControl, and ContainerControl

This comprehensive text starts with a brief overview of the

classes, the FormC#typelanguageadds evenand thengreaterquicklyfunctionalitym ves to. Let'sk y technicalstart withandthe core properties (Table 13-14).

architectural issues for .NET developers.

Table 13-14: Properties of the Form Type

Chapter 15 - Programming with Windows Forms Controls

MinimizedBox

Chapter 16 - The System.IO Namespace

ChapterShowInTaskbar17 - Data AccessShouldwith ADOthis.NETForm be seen on the Windows taskbar?

List of Figures

List of Tables

The truth of the matter is that the Form class does not define a great deal of additional methods. The bulk of a Form's functionality comes from the base classes you have already examined. However, Table 13-15 gives a partial list of some additional methods to be aware of.

Table 13-15: Key Methods of the Form Type

Part Two - The C# Programming Language

Finally, the Form class does define a number of Events (Table 13-16).

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

Table 13-16: Select Events of the Form Type

Chapter 5 - Exceptions and Object Lifetime

ChapterForm6Event- I erfacesMeaningand CollectinonsLife

Chapter 7 - Callback Interfaces, Delegates, and Events

Chapter 8 - Advanced C# Type Construction Techniques

PartClosed,Three -ClosingProgrammingThesewithevents.NET Assembliesare used to determine when the Form is about to close, or has

Chapter 9 - Understandingclosed.NET. Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Fun with the Form Class

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

At this point, you should feel quite comfortable with the functionality provided by the Form class and each of

Chapter 15 - Programming with Windows Forms Controls

its parent classes. Here is a main window (MainForm) that makes use of various members in the inheritance

Chapter 16 - The System.IO Namespace chain:

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

public class MainForm: Form

Chapter 18 - ASP.NET Web Pages and Web Controls

{

Chapter 19 - ASP.NET Web Applications

...

}

private void MainForm_Resize(object sender, System.EventArgs e)

{

Invalidate();

}

// Reference System.Drawing to render this string.

private void MainForm_Paint(object sender, PaintEventArgs e)

{

Graphics g = e.Graphics;

g.DrawString("Windows Forms is for building GUIs!",

Here, a Form object that begins life centered on the screen has been created. In addition, the Resize event

Table of Contents

has been handled. Simply call Invalidate() to force the client area to be refreshed. In this way, the text string

C# and the .NET Platform, Second Edition

rendered on the client area always fits within the bounding rectangle Form's client area (note the use of the

Introduction

DisplayRectangle property).

Part One - Introducing C# and the .NET Platform

ChapterSOURCE1 - The PhilosophyThe SimpleFormAppof .NET can be found under the Chapter 13 subdirectory.

ChapterCODE2 - Building C# Applications

Part Two - The C# Programming Language

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

Chapter 5 - Exceptions and Object Lifetime

Chapter 6 - Interfaces and Collections

Chapter 7 - Callback Interfaces, Delegates, and Events

Chapter 8 - Advanced C# Type Construction Techniques

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

The Life-CycleC# andofthea.WindowsNET Platform, FormSecond EditionType

If you have programmed user interfaces using GUI toolkits such as Java Swing, MFC or the raw Win32 API,

Apress © 2003 (1200 pages)

you are aware that Window types have a number of events which fire during its lifetime. The same holds true

This comprehensive text starts with a brief overview of the

for System.WindowsC# language.Forms.Formand -thderivedn quicklytypesmoves. Tableto key13-17technicaldocumentsand lifetime-centric Form level events.

architectural issues for .NET developers.

Table 13-17: Form Life Time Events

PartLoadThree - ProgrammingOccurswith .afterNET Assembliesthe Form has been allocated into memory, but is not yet visible on

Chapter 9 - Understandingthe screen.NET Assemblies.

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming allow the type to perform any clean up.

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Of course, the true life of a Form begins when the Application.Run() method triggers the type's constructor.

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Once the object has been allocated on the heap, the first event that fires is Load. Within Load, you are free to

Chapter 14 - A Better Painting Framework (GDI+)

configure the look and feel of Form (to augment the work preformed by the InitializeComponent() method),

Chapter 15 - Programming with Windows Forms Controls

prepare any contained child controls (such as ListBoxes, TreeViews, and whatnot), or simply allocate

Chapter 16 - The System.IO Namespace

resources used during the Form's operation (database connections, handles to remote objects, or whatnot).

Chapter 17 - Data Access with ADO.NET

PartOnceFivethe- WebLoadApplicationsevent has fired,and XMLthe nextWebeventServicesis Activate. As mentioned, this event fires when the Form Chapterreceives18focus- ASPas.NETtheWebactivePageswindowand Webon theControlsdesktop. The logical counterpart to the Activate event is (of

course) Deactivate, which fires when the Form loses focus as the active window. As you can guess, the

Chapter 19 - ASP.NET Web Applications

Activate and Deactivate events can fire numerous times over the life of a given Form type.

Chapter 20 - XML Web Services

Index

When the user has chosen to close the Form in question, two close-centric events fire: Closing and Closed.

List of Figures

The Closing event is fired first, and is an ideal place to prompt the end user with the much hated "Are you

List of Tables

sure you wish to close this application?" dialog box. As you are aware, this type of confirmation is quite helpful when you wish to ask the user if s/he wishes to save the current application-centric data. The Closing event works in conjunction with System.ComponentModel.CancelEventHandler delegate, which maps to methods that take a System.ComponentModel.CancelEventArgs type as its second argument (the first, as always is a System.Object). If you set the CancelEventArgs.Cancel property to "true," you prevent the Form from being destroyed and instruct it to return to normal operation. For example:

// Assume you have handled the Closing event in the Form. private void MainForm_Closing(object sender,

System.ComponentModel.CancelEventArgs e)

{

DialogResult dr = MessageBox.Show("Do you REALLY want to close this app?", "Closing event!", MessageBoxButtons.YesNo);

if(dr == DialogResult.No) e.Cancel = true;

else

e.Cancel = false;

Here, we displayThisa messagecompr hensivebox thattextcontainsstarts Yeswithanda briefNooverviewbuttons,ofandthecapture which button was clicked via the returned DialogResultC# languagetypeand(morethenonquicklythis typemovesandtodialogkey technicalboxes inandgeneral in Chapter 15). If the user

architectural issues for .NET developers.

clicks the No button, we set the CancelEventArgs.Cancel property to true, thereby preventing the Form from shutting down.

Table of Contents

Assuming the user does want to close the Form completely, the next event of the Form's life cycle is Closed. C#Here,and youthe .areNETablePlatform,to cleanSecondup anyEditionacquired resources, write to log files, or what have you. Last but not least,

Introductithe Dispose()n method will be called to allow the Form to clean up any contained widgets.

Part One - Introducing C# and the .NET Platform

Chapter 1 - The Philosophy of .NET

A Form Lifetime Example

Chapter 2 - Building C# Applications

PartTo solidifyTwo - ThetheC#sequenceProgrammingof eventsLanguthatgetake place during a Form's lifetime, assume you have a new Chaapplicationter 3 -thatC# Languagehandles theFundamentalsLoad, Activated, Deactivate, Closing, and Close events:

Chapter 4 - Object-Oriented Programming with C#

Chapter 5 - Exceptions and Object Lifetime

public MainForm()

Chapter 6 - Interfaces and Collections

{

Chapter 7 - Callback Interfaces, Delegates, and Events

InitializeComponent();

Chapter this8 - Advanced.ClosingC#+=TypenewConstruction Techniques

Part Three - ProgramSystem.ingComponentModelwith .NET Assemblies.CancelEventHandler(this.MainForm_Closing);

Chapter this9 - Understanding.Load += new.NETSystemAs emblies.EventHandler(this.MainForm_Load);

Chapter this10 - Proces.Closeds, AppDomains,+= new SystemContexts,.EventHandler(thisThreads .MainForm_Closed);

this.Activated += new System.EventHandler(this.MainForm_Activated);

Chapter 11 - Type Reflection, Late Binding, and Attribute-B sed Programming

this.Deactivate += new System.EventHandler(this.MainForm_Deactivate);

Part Four - Leveraging the .NET Libraries

}

Chapter 12 - Object Serialization and the .NET Remoting Layer Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

In each registered event handler, we are going to update a private System.String member variable (named

Chapter 15 - Programming with Windows Forms Controls

lifeTimeInfo) with a simple message that displays the name of the event that has just been intercepted:

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

private void MainForm_Load(object sender, System.EventArgs e)

Part Five - Web Applications and XML Web Services

{ lifeTimeInfo += "Load event\n"; }

Chapter 18 - ASP.NET Web Pages and Web Controls

private void MainForm_Activated(object sender, System.EventArgs e)

{ lifeTimeInfo += "Activate event\n"; }

Chapter 20 - XML Web Services

private void MainForm_Closing(object sender,

Index System.ComponentModel.CancelEventArgs e)

List of Figures

{

List of Tables

...

lifeTimeInfo += "Closing event\n";

}

private void MainForm_Deactivate(object sender, System.EventArgs e) { lifeTimeInfo += "Deactivate event\n"; }

private void MainForm_Closed(object sender, System.EventArgs e) { lifeTimeInfo += "Closed event\n"; }

Finally, in Dispose(), display your string using a MessageBox type:

protected override void Dispose(bool disposing)

{

MessageBox.Show(lifeTimeInfo, "Life time events");

...

}

C# and the .NET Platform, Second Edition

Now, run your application and shift the Form into and out of focus a few times (to trigger the Activate and

Apress © 2003 (1200 pages)

Deactivate events). Once you shut down the Form, you will see a message box looking something like Figure

This comprehensive text starts with a brief overview of the

13-13. C# language and then quickly moves to key technical and architectural issues for .NET developers.

ChapterFigure6 - 13Interfaces-13: FormandeventsCollections

Chapter 7 - Callback Interfaces, Delegates, and Events

SOURCE The FormLifeTime project can be found under the Chapter 13 subdirectory.

Chapter 8 - Advanced C# Type Construction Techniques

CODE

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

Handing FormC# andLevelthe .NETEventsPlatform,aSecondla VSEdition.NET

Although you are always free to handle Form-level events by authoring the necessary logic by hand, it is

Apress © 2003 (1200 pages)

worth pointing out that VS .NET offers design-time support as well. If you examine the IDE's Property

This comprehensive text starts with a brief overview of the

Window, you will C#noticelanguagea smallandlightningthen quicklybolt iconmoves. Onceto keyselected,technicalyouandwill find the set of events for whatever GUI widgetarchitecturalyou selectissuesfromforthe.NETdropdevelopers-down list. box mounted on the top of the Window. Simply locate the name of the event you wish to handle and type in the name to be used as an event handler (or simply double-click the event to generate a default name).

Table of Contents

C#Forandexample,the .NETFigurePlatform,13-14SecondillustratesEditionhow you could handle the Load event for a given Form.

Introduction

Part

Chapter

Chapter

Part

Chapter

Chapter

Chapter

Chapter

Chapter

Chapter

Part

Chapter

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Figure 13-14: Form events

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

If you were now to look at the code behind your Form, you would find that the InitializeComponent()

Chapter 12 - Object Serialization and the .NET Remoting Layer

method has been updated to handle the given event, and a empty event handler has been generated

Chapter 13 - Building a Better Window (Introducing Windows Forms)

automatically. As you might guess, this same technique can be used to autogenerate events for any GUI

Chapter 14 - A Better Painting Framework (GDI+)

widget (as you will see over the course of this text).

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Note The default name used to generate an event handler is formed as ClassName_EventName

Chapter 17 - Data Access with ADO.NET

therefore, it is always a good idea to name your GUI types appropriately before autogenerating

Part Five - Web Applications and XML Web Services

events (unless you like manually renaming auto-generated code).

Chapter 18 - ASP.NET Web Pages and Web Controls

Note Every GUI widget has a default event, which simply refers to the event that will be handled if you

Chapter 19 - ASP.NET Web Applications

double-click the item at design time. For example, a Form's default event is Load, and if you

Chapter 20 - XML Web Services

Index double-click anywhere on a Form type, the IDE will automatically write code to handle this event.

List of Figures

List of Tables

convention to represent a nested type, and has nothing at all to do with C# or .NET code). Recall that

For example, if youC#createdlanguagea andMainMenuthen quicklyto representmov s tothekeytopmosttechnical"File"andmenu, you would add MenuItems

architectural issues for .NET developers.

(for example, Open, Save, Close, Save As) into the collection. As you would expect,

Menu$MenuItemCollection defines members to add and remove MenuItem types, obtain the current count of MenuItems, as well as access a particular member in the collection. Table 13-19 lists some (but not all)

Table of Contents

of the core members.

C# and the .NET Platform, Second Edition

Part Three - Programming with .NET AssembliesAddRange() is helpful in that it allows you to add an array of

Chapter 9 - Understanding .NET AssembliesMenuItems in a single call.

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

PartContains()Four - Leveraging the .NET Libraries Used to determine if a given MenuItem is inside the

collection.

Chapter 12 - Object Serialization and the .NET Remoting Layer Chapter 13 - Building a Better Window (Introducing Windows Forms) Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

Building YourC# andMenuthe .NETSystemPlatfor , Second Edition

Now that you understand the functionality of the abstract Menu class (and the nested MenuItemCollection

Apress © 2003 (1200 pages)

type), you can build your simple File menu. The process begins by creating a MainMenu object. The

This comprehensive text starts with a brief overview of the

MainMenu class representsC# languagetheandcollectionth n quicklyof topmostmoves tomenukey technicalitems (e.gand., File, Edit, View, Tools, Help, and so forth) which appeararchitecturalon a Formissuestypefor..Thus:NET developers.

public class MainForm : Form

Table of Contents

{

C# and the .NET Platform, Second Edition

// The Form's main menu.

Introduction

private MainMenu mainMenu = new MainMenu();

Part One - Introducing C# and the .NET Platform

...

Chapter 1 - The Philosophy of .NET

}

Chapter 2 - Building C# Applications

Part Two - The C# Programming Language

ChaptOnceryou3 -haveC# Languagecreated aFundamMainMenutalsobject, use the Menu$MenuItemCollection.Add() method to insert the Chaptertopmost4 item- Object(the -"File"Ori ntedmenu)Programming. Menu$MenuItemCollectionwith C# .Add() returns a MenuItem object that

represents the newly inserted File menu.

Chapter 5 - Exceptions and Object Lifetime

Chapter 6 - Interfaces and Collections

To insert the subitems (e.g., Exit), you insert MenuItem types into the Menu$MenuItemCollection

Chapter 7 - Callback Interfaces, Delegates, and Events

maintained by the File MenuItem. Finally (and most important), when you are finished populating the

Chapter 8 - Advanced C# Type Construction Techniques

MainMenu type, attach it to the owning Form using the inherited Menu property. If you fail to do so, your

Part Three - Programming with .NET Assemblies

menu system will not be visible! Here are the relevant code updates:

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads public class MainForm : Form

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

{

Part Four - Leveraging the .NET Libraries

// The Form's main menu.

Chapter 12 - Object Serialization and the .NET Remoting Layer private MainMenu mainMenu = new MainMenu();

Chapter 13 - Building a Better Window (Introducing Windows Forms) public MainForm()

Chapter 14 - A Better Painting Framework (GDI+)

{

Chapter 15 - Programming with Windows Forms Controls

// Create the 'File' Menu and add it to the MenuItemCollection.

Chapter 16 - The System.IO Namespace

MenuItem miFile = mainMenu.MenuItems.Add("&File");

Chapter 17 - Data Access with ADO.NET

// Now make the Exit MenuItem and add it to the File MenuItem.

Part Five - Web//ApplicationsThis versionand XML Webof Add()Servicestakes:

// Attach main menu to the Form object. this.Menu = mainMenu;

}

...

}

Notice that if you embed an ampersand within the string name of a menu item, this marks which letter should be underlined to designate the Alt key access combination. Thus, when you specify "&File," you allow the user to activate the File menu by selecting "Alt+F."

When you added the Exit submenu item, you specified an optional shortcut flag. The System.Windows.Forms.Shortcut enumeration is fully detailed in online Help. As you might guess, this enumeration provides fields that specify traditional shortcut keys (Ctrl+C, Ctrl+V, F1, F2, Ins) as well as more exotic combinations.

Here then, is the current code for the simple menu application. Just for kicks, notice how you are able to

C# and the .NET Platform, Second Edition

set the BackColor property of the Form using the MainMenu.GetForm() method:

Apress © 2003 (1200 pages)

// The Simple Menu Application.

This comprehensive text starts with a brief overview of the

public class MainForm : Form

C# language and then quickly moves to key technical and

{architectural issues for .NET developers.

//The Form's main menu.

private MainMenu mainMenu = new MainMenu();

Table of //ContentsRun the application.

public static void Main(string[] args)

C# and the .NET Pla form, Second Edition

{

Introduction

Application.Run(new MainForm());

Part One - Introducing C# and the .NET Platform

}

Chapter 1 - The Philosophy of .NET

// Construct the form.

Chapter 2 - Building C# Applications

public MainForm()

Part Two - The C# Programming Language

Chapter{3 - C# Language Fundamentals

// Configure the initial look and feel of this form.

Chapter 4 - Object-Oriented Programming with C#

Text = "Simple Menu";

Chapter 5 - Exceptions and Object Lifetime

CenterToScreen();

Chapter 6 - Interfaces and Collections

// Create the 'File | Exit' Menu.

Chapter 7 - Callback Interfaces, Delegates, and Events

MenuItem miFile = mainMenu.MenuItems.Add("&File");

Chapter 8 - Advanced C# Type Construction Techniques

miFile.MenuItems.Add(new MenuItem("&Exit",

Part Three - Programming with .NET Assemblies

new EventHandler(this.FileExit_Clicked),

Chapter 9 - Understanding .NET AssembliesShortcut.CtrlX));

Chapter 10 - Processes, AppDomains, Contexts, and Threads

// Attach main menu to the Form object.

Chapter 11 - Type ReflMenuction, Late Binding, and Attribute-Based Programming this. = mainMenu;

Part Four - Leveraging// MainMenuthe .NET.GetForm()Libraries returns a reference to the owning Form.

Chapter 12 - Object// ToSeriaillustrateization nd...the .NET Remoting Layer

Chapter 13 - BuildimainMenugBetter.GetForm()Window (Introducing.BackColorWindows= ColorF rms).Black;

Chapter}14 - A Better Painting Framework (GDI+)

// File | Exit Menu item handler

Chapter 15 - Programming with Windows Forms Controls

private void FileExit_Clicked(object sender, EventArgs e)

Chapter 16 - The System.IO Namespace

Chapter{17 - Data Access with ADO.NET

this.Close(); // Just close the application...

Part Five - Web Applications and XML Web Services

Chapter}18 - ASP.NET Web Pages and Web Controls

}

Chapter 19 - ASP.NET Web Applications Chapter 20 - XML Web Services

Index

ListAddingof F guresAnother Topmost Menu Item

List of Tables

Now, what if you wish to add another topmost menu named "Help" that contains a single subitem named "About" (Figure 13-16)?

Figure 13-16: A more elaborate main menu

The code models the "File | Exit" menu logic almost exactly: Begin by adding a new MenuItem ("Help") to the MainMenu object. From here, add a new subitem ("About"):

public class MainForm : Form

C# and the .NET Platform, Second Edition

// Create the 'File | Exit' Menu.

MenuItem miFile = mainMenu.MenuItems.Add("&File");

Table of ContentsmiFile.MenuItems.Add(new MenuItem("E&xit",

C# and the .NET Platform,newSecondEventHandler(thisEdition .FileExit_Clicked),

}

Chapter 5 - Exceptions and Object Lifetime

// Help | About Menu handler

Chapter 6 - Interfaces and Collections

private void HelpAbout_Clicked(object sender, EventArgs e)

Chapter 7 - Callback Interfaces, Delegates, and Events

{

Chapter 8 - Advanced C# Type Construction Techniques

MessageBox.Show("The amazing menu app...");

Part Three - Programming with .NET Assemblies

}

Chapter 9 - Understanding .NET Assemblies

}

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

ChapterSOURCE12 - Object SerializationThe SimpleMenuand the application.NET Remotingis locatedLay r under the Chapter 13 subdirectory.

CODE

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

Creating a C#Popand-Upthe .MenuNET Platform, Second Edition

Let's now examine the process of building a context-sensitive pop-up (i.e., right-click) menu. The

Apress © 2003 (1200 pages)

ContextMenu class represents the pop-up menu itself. Like the process of building a MainMenu, your goal

This comprehensive text starts with a brief overview of the

is to add individualC#MenuItemsla guage andto thethenMenuItemCollectionquickly moves to keytotechnicalrepresentandthe possible selectable subitems. The following classarchitecturalmakes useissuesof a forpop.-NETup menudevelopersto allow. the user to configure the font size of a string rendered to the client area:

Table of Contents

namespace MainForm

C# and the .NET Platform, Second Edition

{

Introduction

// Helper enum for font size.

Part One - Introducing C# and the .NET Platform

internal enum TheFontSize

Chapter 1 - The Philosophy of .NET

{

Chapter 2 - Building C# Applications

FontSizeHuge = 30,

Part Two - The C# Programming Language

FontSizeNormal = 20,

}

// PopUp_Clicked | X Menu item handler

private void PopUp_Clicked(object sender, EventArgs e)

{

// Figure out the string name of the selected item.

MenuItem miClicked = null; if (sender is MenuItem)

miClicked = (MenuItem)sender;

else

return;

string item = miClicked.Text; if(item == "Huge")

currFontSize = TheFontSize.FontSizeHuge;

if(item == "Normal")

C# and the .NET Platform, Second Edition

currFontSize = TheFontSize.FontSizeNormal;

Apress © 2003 (1200 pages)

currFontSize = TheFontSize.FontSizeTiny;

This comprehensive text starts with a brief overview of the

Invalidate();

} C# language and then quickly moves to key technical and

architectural issues for .NET developers.

private void MainForm_Paint(object sender, PaintEventArgs e)

{

Table of Contents Graphics g = e.Graphics;

g.DrawString("Please click on me...",

C# and the .NET Platform, Second Edition

new Font("Times New Roman", (float)currFontSize),

Introduction

new SolidBrush(Color.Black),

Part One - Introducing C# and the .NET Platform

this.DisplayRectangle);

Chapter 1 - The Philosophy of .NET

}

Chapter}2 - Building C# Applications

Part Two - The C# Programming Language

}

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

ChapterNotice 5that-asExceptionsyou add andthe subitemsObject Lifetimeto the ContextMenu, you have assigned the same event handler to CheachpterMenuItem6 - Interfactype.sWhenand Collectioa givensitem is clicked, the flow of logic brings us to the PopUp_Clicked()

method. Using the "sender" argument, you are able to determine the textual name of the MenuItem and

Chapter 7 - Callback Interfaces, Delegates, and Events

take an appropriate course of action (which works just fine, assuming you are not interested in localizing

Chapter 8 - Advanced C# Type Construction Techniques

the application).

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Also notice that once you have created a ContextMenu, you associate it to the Form using the

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Control.ContextMenu property. Be aware that any control can be assigned a context menu. For example,

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

you could create a Button object on a dialog box that responds to a particular context menu. In this way,

Part Four - Leveraging the .NET Libraries

the menu would only be displayed if the mouse button were clicked while within the bounding rectangle of

Chapter 12 - Object Serialization and the .NET Remoting Layer the button.

Chapter 13 - Building a Better Window (Introducing Windows Forms) Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

C# and the .NET Platform, Second Edition

SOURCE The PopUpMenu project is contained under the Chapter 13 subdirectory.

CODE by Andrew Troelsen ISBN:1590590554

Apress © 2003 (1200 pages)

This comprehensive text starts with a brief overview of the C# language and then quickly moves to key technical and architectural issues for .NET developers.

Table of Contents

C# and the .NET Platform, Second Edition

Introduction

Part One - Introducing C# and the .NET Platform

Chapter 1 - The Philosophy of .NET

Chapter 2 - Building C# Applications

Part Two - The C# Programming Language

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

Chapter 5 - Exceptions and Object Lifetime

Chapter 6 - Interfaces and Collections

Chapter 7 - Callback Interfaces, Delegates, and Events

Chapter 8 - Advanced C# Type Construction Techniques

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

Building a MenuC# a d theUsing.NET Platform,VisualSecondStudioEdition.NET

Indeed, knowledge is power. On the other hand, now that you understand how you can write raw C# code

Apress © 2003 (1200 pages)

to create and configure a menu system, let's examine how Visual Studio .NET can offer some design-time

This comprehensive text starts with a brief overview of the

assistance. To begin,C# languageassumeandthatthenyouquicklyhave createdmoves atonewkey C#technicalWindowsand Application project workspace.

architectural issues for .NET developers.

Using the Toolbox window, double-click the MainMenu icon. Once you do, you see a new icon appear at the icon tray of the design-time template. Furthermore, you see a design-time representation of your menu

Tableattachedof Contentsto the top of your Form. To add new menu items, simply double-click a slot and type away!

C#Considerand theFigure.NET Platform,13-18. Second Edition

Introduction

Part

Chapter

Chapter

Part

Chapter

Chapter

Chapter

Chapter

Chapter

Chapter

Part

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Figure 13-18: The integrated menu editor of VS .NET

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

As far as handling events for a given item (as well as configuring a number of other properties), select the

Chapter 16 - The System.IO Namespace

MenuItem you wish to configure using the VS .NET Properties window (Figure 13-19).

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter

Chapter

Chapter

Index

List of

List of

Figure 13-19: Handing menu-centric events using VS .NET

Once you enter the name of our event handler, the Visual Studio .NET IDE automatically generates stub code for the event handler:

private void mnuFileExit_Clicked (object sender, System.EventArgs e)

{

// Respond to File | Exit selection...

}

C# and the .NET Platform, Second Edition

Be aware, that asApressyou modify© 2003 your(1200 menuspages) at design time, the IDE is updating the InitializeComponent() helper function, asThiswellcompreheas addingsivemembertext startsvariableswith a tobriefrepresentoverviewtheoftypesthe you are manipulating at design time. If you examineC# languagethe code,andthingsthen(Iquicklyhope) lookm vesveryto familiarkey technical. and

architectural issues for .NET developers.

Note VS .NET also supports design-time configuration of pop-up menus. Simply drag a ContextMenu item onto your Form and edit the selections using the menu editor. Once this has been done,

Table of Contents

assign this object to the ContextMenu property of the widget you wish to leverage this pop-up.

C# and the .NET Platform, Second Edition

Introduction

Part One - Introducing C# and the .NET Platform

Chapter 1 - The Philosophy of .NET

Chapter 2 - Building C# Applications

Part Two - The C# Programming Language

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

Chapter 5 - Exceptions and Object Lifetime

Chapter 6 - Interfaces and Collections

Chapter 7 - Callback Interfaces, Delegates, and Events

Chapter 8 - Advanced C# Type Construction Techniques

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

UnderstandingC# andStatusthe .NET PlBarstform, Second Edition

In addition to a menu system, many Forms also maintain a status bar. Status bars may be divided into any

Apress © 2003 (1200 pages)

number of "panes." Panes hold some textual (or graphical) information such as menu help strings, or

This comprehensive text starts with a brief overview of the other application-C#specificlanguageinformationand then. ThequicklyStatusBarmoves totypekeyderivestechnicaldirectlyand from

System.Windowsarchitectural.Forms.Controlissues. In foraddition.NET developersto the inherited. members, StatusBar defines the core

properties shown in Table 13-21.

Part Four - Leveraging the .NET Libraries

Once you create a StatusBar, your next task is to add any number of panels (represented by the

Chapter 12 - Object Serialization and the .NET Remoting Layer

StatusBarPanel class) into the nested StatusBar$StatusBarPanelCollection. Be aware that the constructor

Chapter 13 - Building a Better Window (Introducing Windows Forms)

of StatusBarPanel automatically configures the new panel with a default look and feel (therefore, if you

Chapter 14 - A Better Painting Framework (GDI+)

are happy with this initial configuration, your programming task is made even simpler). Table 13-22 lists of

Chapterthe core15members- Programmingof the StatusBarPanelwith Windows FormstypeControls.

Chapter 16 - The System.IO Namespace

ChTablept r 137-22:- DataPropertiesAccess withof theADOStatusBarPanel.NET Type

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Property

Chapter 19 - ASP.NET Web Applications

ChapterAlignment20 - XML Web ServicesDetermines the alignment of text in the pane.

Apress © 2003 (1200 pages)

Building a StatusThis comprehensiveBar text starts with a brief overview of the

C# language and then quickly moves to key technical and

architectural issues for .NET developers.

To illustrate, let's construct a StatusBar object that is divided into two panes. The first pane is used to show helpful prompts describing the functionality of each menu selection. The second pane displays the current

system time. And let's place a small icon on the far left side of the first pane (just to keep things

Table of Contents

interesting). Check out Figure 13-20.

C# and the .NET Platform, Second Edition

Introduction

Part

Chapter

Chapter

Part

Chapter

Chapter

Chapter

Chapter 6 - Interfaces and Collections

Figure 13-20: A custom status bar

Chapter 7 - Callback Interfaces, Delegates, and Events

Chapter 8 - Advanced C# Type Construction Techniques

Assume you have updated the SimpleMenu application created earlier in this chapter, to support this

Part Three - Programming with .NET Assemblies

status bar. Like any Control-derived type, the StatusBar needs to be added to the Form's Controls

Chapter 9 - Understanding .NET Assemblies

collection (more details on this collection in Chapter 15). As you might guess, this collection contains an

Chapter 10 - Processes, AppDomains, Contexts, and Threads

entry for any GUI widget mounted on the client area, including StatusBars types. Here is the status bar

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming logic:

Part Four - Leveraging the .NET Libraries

List of Tablesprivate void BuildStatBar()

{

// Configure the status bar.

statusBar.ShowPanels = true;

statusBar.Size = new System.Drawing.Size(212, 20);

statusBar.Location = new System.Drawing.Point(0, 216);

// AddRange() allows you to add a set of panes at once.

statusBar.Panels.AddRange(new StatusBarPanel[]

{sbPnlPrompt, sbPnlTime});

//Configure prompt panel.

sbPnlPrompt.BorderStyle = StatusBarPanelBorderStyle.None;

sbPnlPrompt.AutoSize = StatusBarPanelAutoSize.Spring;

sbPnlPrompt.Width = 62;

sbPnlPrompt.Text = "Ready";

// Configure time pane.

sbPnlTime.AutoSize = StatusBarPanelAutoSize.Spring;

timer1.Enabled = true;

C# and the .NET Platform, Second Edition timer1.Tick += new EventHandler(timer1_Tick);

}Apress © 2003 (1200 pages)

This comprehensive text starts with a brief overview of thesecond

// This method will be called (roughly) every .

C# language and then quickly moves to key technical and private void timer1_Tick(object sender, EventArgs e)

architectural issues for .NET developers.

{

DateTime t = DateTime.Now;

string s = t.ToLongTimeString();

Table of Contents

// Change text of pane to current time.

C# and the .NET Platform, Second Edition sbPnlTime.Text = s;

Introduction

}

Part One - Introducing C# and the .NET Platform

}

Chapter 1 - The Philosophy of .NET

Chapter 2 - Building C# Applications

Part Two - The C# Programming Language

ChapterNotice 3that-theC# TimerLanguageeventFundamentalshandler makes use of the DateTime type. Here, you simply find the current

Chaptersystem4time- Objectusing-theOrientedNow pProperty,grammiandg withuse itC#to set the Text property of the correct StatusBarPanel

Chapterobject.5 - Exceptions and Object Lifetime

Chapter 6 - Interfaces and Collections

ChapterDisplaying7 - CallbackMenuInterfaces,SelectionDelegates, andPromptsEvents

Chapter 8 - Advanced C# Type Construction Techniques

PartFinally,Threeyou- Programmingmust configurewiththe.NETfirstAssembliespane to hold menu help strings. As you know, most applications send

Chaptera small9bit-ofUnderstandingtext information.NETtoAssembliesthe first pane of a status bar whenever the end user selects a menu item

Chapter(e.g., "This10 -terminatesProcesses, AppDomains,the application")Contexts,. and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Assume the menu system for this application is identical to the Simple Menu application. This time, however, you need to respond to the Select event of each subitem. When the user selects "File | Exit" or "Help | About" you tell the first StatusBarPanel object to display a given text message. Note, you also

handle the MenuComplete event (described in the bold code comment below). Here is the update:

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

public class MainForm: Form

Chapter 16 - The System.IO Namespace

{

Chapter 17 - Data Access with ADO.NET

...

Part Five - Web Applications and XML Web Services

public MainForm ()

Chapter 18 - ASP.NET Web Pages and Web Controls

{

// Helper functions.

private void BuildMenuSystem()

{

// First make the main menu.

C# and the .NET Platform, Second Edition mainMenu = new MainMenu();

Apress © 2003 (1200 pages)

MenuItem miFile = mainMenu.MenuItems.Add("&File");

This comprehensive text starts with a brief overview of the miFile.MenuItems.Add(new MenuItem("E&xit",

C# language and then quickly moves to key technical and

new EventHandler(this.FileExit_Clicked), architectural issues for .NET developers.

Shortcut.CtrlX));

// Handle the Select event for the Exit menu item.

miFile.MenuItems[0].Select += new EventHandler(FileExit_Selected);

Table of Contents

// Now create a 'Help | About' menu.

C# and the .NET Platform, Second Edition

MenuItem miHelp = mainMenu.MenuItems.Add("Help");

Introduction

miHelp.MenuItems.Add(new MenuItem("&About",

Part One - Introducing C# and the .NET Platform

new EventHandler(this.HelpAbout_Clicked),

Chapter 1 - The Philosophy of .NET

Shortcut.CtrlA));

Chapter 2 - Building C# Applications

// Handle the Select event for the About menu item.

Part Two - The C# Programming Language

miHelp.MenuItems[0].Select +=

Chapter 3 - C# Language Fundamentals

new EventHandler(HelpAbout_Selected);

Chapter 4 - Object-Oriented Programming with C#

// Attach main menu to the Form object.

Chapter 5 - Exceptions and Object Lifetime

this.Menu = mainMenu;

Chapter 6 - Interfaces and Collections

}

Chapter... 7 - Callback Interfaces, Delegates, and Events

Chapter} 8 - Advanced C# Type Construction Techniques

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Excellent! As you may guess, the Visual Studio IDE also provides some design-time assistance to facilitate

Chapter 10 - Processes, AppDomains, Contexts, and Threads

the building of status bar objects. In just a bit, you examine how to build a toolbar using tools provided by

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

the IDE. Once you understand this process, you should have no problems designing status bars using the

Part Four - Leveraging the .NET Libraries

design-time tools.

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

SOURCE The StatusBarApp project is included under the Chapter 13 subdirectory.

Chapter 14 - A Better Painting Framework (GDI+)

CODE

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

Building a ToolC# andBarthe .NET Platform, Second Edition

The final Form level GUI item to examine in this chapter is the ToolBar type. As you know, tool bars typically

Apress © 2003 (1200 pages)

provide an alternate means to activate a given menu item. Thus, if the user would rather click a Save button,

This comprehensive text starts with a brief overview of the

this has the sameC#effectlanguageas selectingand then"Filequickly| Savemoves." In tothekeyWindowstechnicalFormsand namespace, a handful of types are defined to allow youarchitecturalto build suchissuesa beastfor .NET. Let'sdevelopersstart with. the ToolBar class itself. Note the core properties as seen in Table 13-24.

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Wrappable ToolBar buttons can optionally "wrap" to the next line when the ToolBar

Chapter 11 - Type Reflection,becomesLate Binditoo narrowg, andtoAttribincludete-Basedall buttonsProgrammingon the same line.

Part Four - Leveraging the .NET Libraries

ChapterWhen a12Form- ObjectmaintainsSerializationToolBarand the(or .two),NET Remotingthe goal isLayerto create some number of individual ToolBarButton

Chapterobjects13and- Buildingadd thema Betterto the WindowToolBar(Intr$ToolBarButtoducing WindowsCollectionForms)type. Each button may contain text, images,

Chapteror both14. To- keepA BetterthingsPaintingsimple,Frameworklet's build(GDI+)a toolbar containing two buttons displaying text prompts only. Table

Chapter13-25 presents15 - Prograsomemingimportantwith WindowsmembersFormsof theControlsToolBarButton.

Chapter 16 - The System.IO Namespace

Table 13-25: Properties of the ToolBarButton Type

Ch pter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Property

Chapter 19 - ASP.NET Web Applications

ChapterDropDownMenu20 - XML Web ServicesToolBarButtons can optionally specify a pop-up menu that is shown whenever the drop-down button is pressed. This property lets you control just which menu is shown. Note that this is only shown if the Style property is set to DropDownButton.

Returns the index of the image that this ToolBarButton is using. The index comes from the parent ToolBar's ImageList.

Returns the style of the ToolBar button. This will form the

ToolBarButtonStyle enumeration.

The caption that will be displayed in this ToolBar button.

If the parent ToolBar has the ShowToolTips property turned on, then this property describes the text that will be displayed for this button.

Indicates whether the button is visible or not. If the button is not visible, it will not be shown and will be unable to receive user input.

Your custom toolbar will contain two buttons, echoing the behavior supplied by the Save and Exit menu items. Here is the code update:

public class MainForm: Form

C# and the .NET Platform, Second Edition

{

// State data for the toolbar and two buttons.

Apress © 2003 (1200 pages)

private ToolBarButton tbSaveButton = new ToolBarButton();

This comprehensive text starts with a brief overview of the

private ToolBarButton tbExitButton = new ToolBarButton();

C# language and then quickly moves to key technical and

private ToolBar toolBar = new ToolBar(); architectural issues for .NET developers.

public MainForm()

{

...

Table of Contents

BuildToolBar(); // Helper function.

C# and the .NET Platform, Second Edition

}

Introduction

private void BuildToolBar()

Part One - Introducing C# and the .NET Platform

{

Chapter 1 - The Philosophy of .NET

// Configure each button.

Chapter 2 - Building C# Applications

tbSaveButton.Text = "Save";

Part Two - The C# Programming Language

tbSaveButton.ToolTipText = "Save";

Chapter 3 - C# Language Fundamentals tbExitButton.Text = "Exit";

Chapter 4 - Object-Oriented Programming with C# tbExitButton.ToolTipText = "Exit";

Chapter 5 - Exceptions and Object Lifetime

// Configure ToolBar and add buttons.

Chapter 6 - Interfaces and Collections

toolBar.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;

Chapter 7 - Callback Interfaces, Delegates, and Events

toolBar.ShowToolTips = true;

Chapter 8 - Advanced C# Type Construction Techniques

toolBar.Buttons.AddRange(new ToolBarButton[]

Part Three - Programming with .NET Assemblies

{ tbSaveButton, tbExitButton} );

Chapter 9 - Understanding .NET Assemblies

toolBar.ButtonClick += new

Chapter 10 - Processes,ToolBarButtonClickEventHandler(ToolBarAppDomains, Contexts, Thre ds _Clicked));

Chapter 11 - Type// Reflection,Add theLatenewBinding,bar toandtheAttributeControls-Based Programmingcollection.

Part Four - Leveragingthis.Controlsthe .NET Libraries.Add(toolBar);

Chapter }12 - Object Serialization and the .NET Remoting Layer

Chapter //13 -ButtonBuilding aclickBetter Windowhandler(Introducing. Windows Forms)

private void ToolBar_Clicked(object sender, ToolBarButtonClickEventArgs e)

Chapter 14 - A B tter Painting Framework (GDI+)

{

Chapter 15 - Programming with Windows Forms Controls

MessageBox.Show(e.Button.ToolTipText);

Chapter 16 - The System.IO Namespace

}

Chapter 17 - Data Access with ADO.NET

...

Part Five - Web Applications and XML Web Services

}

Chapter 18 - ASP.NET Web Pages and Web Controls Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

When you run the application, things will look quite bland (after all, how many toolbars display only text)? You

Index

will add some images in just a moment, but first let's analyze some code. The BuildToolBar() helper function

List of Figures

begins by configuring some basic properties for each ToolBarButton. Next, add them to the ToolBar Listcollectionof Tablesusing the AddRange() method (rather than calling Add() multiple times). To handle the Click events for a given button, you must handle the ButtonClick event.

toolBar.ButtonClick += new ToolBarButtonClickEventHandler(ToolBar_Clicked);

The ToolBarButtonClickEventHandler delegate can only call methods taking a second parameter of type ToolBarButtonClickEventArgs. This type may be examined to determine which button sent the event, using the Button property:

private void ToolBar_Clicked(object sender, ToolBarButtonClickEventArgs e)

{

// Just show the corresponding tool bar text.

MessageBox.Show(e.Button.ToolTipText);

}

C# and the .NET Platform, Second Edition

This comprehensive text starts with a brief overview of the

Real Toolbar buttons contain images. When you wish to configure your buttons to do so, the first step is to

C# language and then quickly moves to key technical and

have the Form create an ImageList type. This class represents a set of images that are consumed by some architectural issues for .NET developers.

other type (like a ToolBar). If you have ever created a toolbar using Visual Basic 6.0, you should feel right at home with this aspect of Windows Forms. Let's update your existing ToolBarForm to make use of two icons

for display purposes, in addition to simple text strings. Here is the relevant update:

Table of Contents

C# and the .NET Platform, Second Edition

public class MainForm: Form

Introduction

{

Part One - Introducing C# and the .NET Platform

// Contains the images used by the toolbar.

Chapter 1 - The Philosophy of .NET

private ImageList toolBarIcons = new ImageList();

Chapter 2 - Building C# Applications

...

Part Two - The C# Programming Language

private void BuildToolBar()

Chapter 3 - C# Language Fundamentals

{

Chapter 4 - Object-Oriented Programming with C#

// Configure save button.

Chapter 5 - Exceptions and Object Lifetime tbSaveButton.ImageIndex = 0;

Chapter 6 - Interfaces and Collections tbSaveButton.ToolTipText = "Save";

Chapter 7 - Callback Interfaces, Delegates, and Events

// Configure exit button.

Chapter 8 - Advanced C# Type Construction Techniques tbExitButton.ImageIndex = 1;

Part Three - Programming with .NET Assemblies

tbExitButton.ToolTipText = "Exit";

Chapter 9 - Understanding .NET Assemblies

// Create ToolBar and add buttons.

Chapter 10 - Processes, AppDomains, Contexts, and Threads

toolBar.ImageList = toolBarIcons;

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

...

Part Four - Leveraging the .NET Libraries

// Load images (again, the icons need to be in the app dir).

Chapter 12 - Object Serialization and the .NET Remoting Layer

toolBarIcons.ImageSize = new System.Drawing.Size(32, 32);

Chapter 13 - BuildingtoolBarIconsBetter Window.Images(Introducing.Add(newWindowsIcon("filesaveForms) .ico"));

Chapter 14 - A toolBarIconsBetter Painting Framework.Images(GDI+).Add(new Icon("fileexit.ico"));

Chapter 15 - ProgrammingtoolBarIconswith Windows.ColorDepthForms Contr= ColorDepthls .Depth16Bit;

toolBarIcons.TransparentColor = System.Drawing.Color.Transparent;

Chapter 16 - The System. O Namespace

...

Chapter 17 - Data Access with ADO.NET

Part Five}- Web Applications and XML Web Services

}

Chapter 18 - ASP.NET Web Pages and Web Controls Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Notice the following points:

Index

ListofYouFiguresmust tell each ToolBarButton which image to use, via the ImageIndex property.

List of Tables

You add new images to the ImageList class using the Images.Add() method.

The ToolBar itself must be told which ImageList it is associated with using the ImageList property.

If you now run the application (Figure 13-21), you will see a much more pleasing end result (if you wish these buttons to look more standard, simply adjust the size to 16 × 16):

Edition

ISBN:1590590554

a brief overview of the

to key technical and

developers.

Table

Figure 13-21: A custom tool bar

C# and the .NET Platform, Second Edition

Part Three - Programming with .NET Assemblies

Chapter 9 - Understanding .NET Assemblies

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Chapter 11 - Type Reflection, Late Binding, and Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

Chapter 13 - Building a Better Window (Introducing Windows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

Chapter 16 - The System.IO Namespace

Chapter 17 - Data Access with ADO.NET

Part Five - Web Applications and XML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of Figures

List of Tables

Building ToolBarsC# and theat.NETDesignPlatform,TimeSecond Edition

As you would guess, VS .NET has design-time support for constructing toolbar entities. The first step is to

Apress © 2003 (1200 pages)

drag a ToolBar from the Toolbox window onto your design-time template. Design-time configuration of the

This comprehensive text starts with a brief overview of the

ToolBar is accomplishedC# languageusingandthethenPropertiesquickly movesWindowto. Forkey example,technical andif you wish to add buttons to the ToolBar type, doublearchitectural-click theissButtonses for property.NET developers. This opens. a dialog that allows you to add, remove, and configure the individual ToolBarButton items (Figure 13-22).

Table of Contents

C# and

Part

Chapter

Chapter

Part

Chapter

Chapter

Chapter

Chapter

Chapter

Chapter

Part

Chapter

Chapter Threads

ChapterFigure11 - 13Type-22:Reflection,ToolbarsLatelaBinding,VS .NETand Attribute-Based Programming

Part Four - Leveraging the .NET Libraries

Chapter 12 - Object Serialization and the .NET Remoting Layer

ChapterAdding13 - anBuildingImageListBetter Windowat (IntroduciDesigngTimeWindows Forms)

Chapter 14 - A Better Painting Framework (GDI+)

Notice how this same dialog also allows you to assign an iconic image to each button using the

Chapter 15 - Progra ming with Windows Forms Controls

ImageIndex property. However, this property is useless until you add an ImageList type to your current

Chapter 16 - The System.IO Namespace

project. To add an ImageList member to a Form at design time, return to the Toolbox window and double-

Chapter 17 - Data Access with ADO.NET

click the icon. At this point, you can use the Properties window to add the individual images using the

Part Five - Web Applications and XML Web Services

Images property. Once you have added each image file to the ImageList, inform the ToolBar which

Chapter 18 - ASP.NET Web Pages and Web Controls

ImageList it is to make use of using the Properties window (Figure 13-23).

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

Index

List of

List of

Figure 13-23: Assigning an ImageList via VS .NET

At this point, return to the ToolBar button editor and map a given image in the ImageList to each button (Figure 13-24).

Edition

ISBN:1590590554

brief overview of the

to key technical and

.

Table

C# and

Part