Now that you have seen the DirectoryInfo type in action, you can learn about the Directory type. By and

Apr ss © 2003 (1200 pages)

large, the members of the Directory mimic the same functionality provided by the instance-level members

This comprehensive text starts with a brief overview of the

defined by DirectoryInfo,C# languagewith andfewthennotablequicklyexceptionsmoves to(GetLogicalDrives()key technical and for one). They also generally return strings ratherarchitecturalthan objectsissues. Dueforto.NETthedeveloperscommon public. interface of each type, I assume you will consult online help to view each member of the Directory class.

TableThisoffinalContentsiteration of the MyDirectory class lists the names of all drives mapped to the current computer C#andandusesthethe.NETstaticPlatform,DirectorySecond.Delete()Editionmethod to remove the \MyFoo and \MyBar\MyQaaz subdirectories

previously created:

Introduction

Part One - Introducing C# and the .NET Platform

Chapterclass1MyDirectory- The Phil sophy of .NET

Chapter{ 2 - Building C# Applications

Part Twopublic- The C#staticProgrammingvoidLanguageMain(String[] args)

Chapter {3 - C# Language Fundamentals

DirectoryInfo dir = new DirectoryInfo(@"C:\WinNT");

Chapter 4 - Object-Oriented Programming with C#

Chapter 5 - Exceptions and Object Lifetime

// Now call some static members of the Directory class.

Chapter 6 - Interfaces and Collections

// List all drives on current computer.

Chapter 7 - Callback Interfaces, Delegates, and Events

string[] drives = Directory.GetLogicalDrives();

Chapter 8 - Advanced C# Type Construction Techniques

Console.WriteLine("Here are your drives:");

Part Three - Programming with .NET Assemblies

foreach(string s in drives)

Chapter 9 - Understanding .NET Assemblies

{

Chapter 10 - Processes, AppDomains, Contexts, and Threads

Console.WriteLine("->{0} ", s);

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

}

Part Four - Leveraging the .NET Libraries

// Delete what was created.

Chapter 12 - Object Serialization and the .NET Remoting Layer

Console.Write("Going to delete\n->" + dir.FullName +

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

"\\MyBar\\MyQaaz.\nand\n->" + dir.FullName +

Chapter 14 - A Better Painting Framework (GDI+)

"\\MyFoo.\n" +"Press a key to continue!");

Chapter 15 - Programming with Windows Forms Controls

Console.Read();

Chapter 16 - The System.IO Namespace

try

Chapter 17 - Data{ Access with ADO.NET

Part Five - Web ApplicatDirectoryons and XML.Delete(@"C:\WinNT\MyFoo");Web S rvices

Console.WriteLine(e.Message);

}

}

}

Great! At this point you have investigated some core behaviors of the Directory and DirectoryInfo types. Next, you need to learn how to create, open, close, and destroy the files that populate a given directory.

SOURCE The MyDirectoryApp project is located under the Chapter 16 subdirectory.

CODE

The FileInfoC#Classand the .NET Platform, Second Edition

The role of the FileInfo class is to obtain a number of details regarding existing files on your hard drive

Apress © 2003 (1200 pages)

(time created, size, file attributes, and so forth) as well as aid in the creation, copying, moving, and

This comprehensive text starts with a brief overview of the

destruction of filesC#. Inlanguageadditionandto thethensetquicklyof functionalitymoves to inheritedkey technicalby FileSystemInfo,and Table 16-5 describes some core membersarchitecturalunique toissuthesFileInfofor .NETclassdevelopers. .

Table 16-5: FileInfo Core Members

ChaptOpenText()r 17 - Data Access withCreatesADO.aNETStreamReader type (described later) that reads from an existing

Part Five - Web ApplicationstextandfileXML Web Services

Chapter 18 - ASP.NET Web Pages and Web Controls

Chapter 19 - ASP.NET Web Applications

Chapter 20 - XML Web Services

First, you should be aware that many methods defined by FileInfo return a specific stream-centric type

Index

(FileStream, StreamWriter, StreamReader, and so forth) that allows you to begin reading and writing data

List of Figures

to (or reading from) the associated file in a variety of ways. We'll check out these types later in this

List of Tables

chapter; however, until then, the following code block illustrates the most generic (and least flexible) way to create a file programmatically:

public class FileManipulator

{

public static int Main(string[] args)

{

// Make a new file on the C: drive.

FileInfo f = new FileInfo(@"C:\Test.txt");

FileStream fs = f.Create();

// Print some basic traits of the test.txt file.

Console.WriteLine("Creation: {0} ", f.CreationTime); Console.WriteLine("Full name: {0} ", f.FullName); Console.WriteLine("Full atts: {0} ", f.Attributes.ToString()); Console.Write("Press a key to delete file");

Console.Read();

// Close the file stream and delete the file.

C# and the .NET Platform, Second Edition fs.Close();

Notice that the FileInfo.Create() method returns a FileStream type that allows you to close the new file

Table of Contents

before removing it from the hard drive. (You will see additional uses of FileStream later in the chapter.)

C# and the .NET Platform, Second Edition

When you run this application, you will be able to find your newly created *.txt file under the C drive.

Introduction

Part One - Introducing C# and the .NET Platform

Examining the FileInfo.Open() Method

Chapter 1 - The Philosophy of .NET

Chapter 2 - Building C# Applications

The FileInfo.Open() method can be used to open existing files as well as create new files with far more

Part Two - The C# Programming Language

precision than FileInfo.Create(). To illustrate, ponder the following logic:

Chapter 3 - C# Language Fundamentals

Chapter 4 - Object-Oriented Programming with C#

// Open (or create) a file with read/write attributes (no sharing),

Chapter 5 - Exceptions and Object Lifetime

// and store file handle in a FileStream object.

Chapter 6 - Interfaces and Collections

FileInfo f2 = new FileInfo(@"C:\HelloThere.ini");

Chapter 7 - Callback Interfaces, Delegates, and Events

FileStream s = f2.Open(FileMode.OpenOrCreate,FileAccess.ReadWrite,

Chapter 8 - Advanced C# Type Construction Techniques

FileShare.None);

Part Three - Programming with .NET Assemblies

...

Chapter 9 - Understanding .NET Assemblies

s.Close();

Chapter 10 - Processes, AppDomains, Contexts, and Threads

f2.Delete();

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

Part Four - Leveraging the .NET Libraries

This version of the overloaded Open() method requires three parameters. The first parameter specifies

Chapter 12 - Object Serialization and the .NET Remoting Layer

the general flavor of the open request (e.g., make a new file, open an existing file, append to a file, and so

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

on), which is specified using the FileMode enumeration (Table 16-6).

Chapter 14 - A Better Painting Framework (GDI+)

Chapter 15 - Programming with Windows Forms Controls

The second parameter, a value from the FileAccess enumeration, is used to determine the read/write behavior of the underlying stream (Table 16-7).

FileInfo.AppendText() Members

C# and the .NET Platform, Second Edition

Another "open-centric" member of the FileInfo type is OpenText(). Unlike Open(), OpenRead(), and

Apress © 2003 (1200 pages)

OpenWrite(), the OpenText() method returns an instance of the StreamReader type, rather than a

This comprehensive text starts with a brief overview of the

FileStream-derived type:

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

// Get a StreamReader object.

FileInfo f5 = new FileInfo(@"C:\bootlog.txt");

Table of Contents

StreamReader sreader = f5.OpenText();

C#...and the .NET Platform, Second Edition

Intsreaderoduction.Close();

Part One - Introducing C# and the .NET Platform

Chapter 1 - The Philosophy of .NET

The final two methods of interest at this point are CreateText() and AppendText(), both of which return a

Chapter 2 - Building C# Applications

StreamWriter reference, as shown here:

Part Two - The C# Programming Language

Chapter 3 - C# Language Fundamentals

// Get some StreamWriters.

Chapter 4 - Object-Oriented Programming with C#

FileInfo f6 = new FileInfo(@"D:\AnotherTest.txt");

Chapter 5 - Exceptions and Object Lifetime

f6.Open(FileMode.Create, FileAccess.ReadWrite);

Chapter 6 - Interfaces and Collections

StreamWriter swriter = f6.CreateText();

Chapter 7 - Callback Interfaces, Delegates, and Events

...

Chapter 8 - Advanced C# Type Construction Techniques

swriter.Close();

Part Three - Programming with .NET Assemblies

FileInfo f7 = new FileInfo(@"D:\FinalTest.txt");

Chapter 9 - Understanding .NET Assemblies f7.Open(FileMode.Create, FileAccess.ReadWrite);

Chapter 10 - Processes, AppDomains, Contexts, and Threads

StreamWriter swriterAppend = f7.AppendText();

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

...

Part Four - Leveraging the .NET Libraries

swriterAppend.Close();

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

ChapterAt this point,14 - AyouBetterhavePaintinggoodFrameworkfeel for the(GDI+)functionality provided by the FileInfo type. (You will see exactly Chapterwhat to15do-withProgrammingthe FileStream,with WindowsStreamReader,Forms Controlsand StreamWriter types shortly.)

Chapter 16 - The System.IO Namespace

Note Be aware that the File type provides almost identical functionality using a number of static

Chapter 17 - Data Access with ADO.NET

members. You will see the File type in action where appropriate, but be sure to check out online

Part Five - Web Applications and XML Web Services

help for an exhaustive listing of each member.

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