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FileInfo.OpenWrite Method

Creates a write-only FileStream.

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)

public FileStream OpenWrite ()
public FileStream OpenWrite ()
public function OpenWrite () : FileStream
Not applicable.

Return Value

A new write-only unshared FileStream object.

Exception typeCondition

UnauthorizedAccessException

path is read-only or is a directory.

DirectoryNotFoundException

The specified path is invalid, such as being on an unmapped drive.

For a list of common I/O tasks, see Common I/O Tasks.

The following example opens a file for writing and then reads from the file.

using System;
using System.IO;
using System.Text;

class Test 
{
    public static void Main() 
    {
        string path = @"c:\MyTest.txt";
        FileInfo fi = new FileInfo(path);

        if (!fi.Exists) 
        {
            //Create the file.
            fi.Create();
        }

        // Open the stream for writing.
        using (FileStream fs = fi.OpenWrite()) 
        {
            Byte[] info = 
                new UTF8Encoding(true).GetBytes("This is to test the OpenWrite method.");

            // Add some information to the file.
            fs.Write(info, 0, info.Length);
        }

        // Open the stream and read it back.
        using (FileStream fs = fi.OpenRead()) 
        {
            byte[] b = new byte[1024];
            UTF8Encoding temp = new UTF8Encoding(true);

            while (fs.Read(b,0,b.Length) > 0) 
            {
                Console.WriteLine(temp.GetString(b));
            }
        }
    }
}
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//This is to test the OpenWrite method.
//
//
//
//
//
//
//
//
//
//
//

import System.*;
import System.IO.*;
import System.Text.*;

class Test
{
    public static void main(String[] args)
    {
        String path = "c:\\MyTest.txt";

        // Delete the file if it exists.
        if (!(File.Exists(path))) {
            // Create the file.
            FileStream fs = File.Create(path);
            try {
            }
            finally {
                fs.Dispose();
            }
        
        }

        // Open the stream for writing.
        {
            FileStream fs = File.OpenWrite(path);
            try {
                ubyte info[] = (new UTF8Encoding(true)).GetBytes("This is to " 
                    + " test the OpenWrite method.");

                // Add some information to the file.
                fs.Write(info, 0, info.length);
            }
            finally {
                fs.Dispose();
            }
        }
        // Open the stream and read it back.
        {
            FileStream fs = File.OpenRead(path);

            try {
                ubyte b[] = new ubyte[1024];
                UTF8Encoding temp = new UTF8Encoding(true);

                while ((fs.Read(b, 0, b.length) > 0)) {
                    Console.WriteLine(temp.GetString(b));
                }
            }
            finally {
                fs.Dispose();
            }
        }
    } //main
} //Test
//This code produces output similar to the following; 
//results may vary based on the computer/file structure/etc.:
//
//This is to test the OpenWrite method.
//
//
//
//
//
//
//
//
//
//
//
//

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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