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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

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.

The following table lists examples of other typical or related I/O tasks.

To do this...

See the example in this topic...

Create a text file.

How to: Write Text to a File

Write to a text file.

How to: Write Text to a File

Read from a text file.

How to: Read Text from a File

Append text to a file.

How to: Open and Append to a Log File

File.AppendText

FileInfo.AppendText

Rename or move a file.

File.Move

FileInfo.MoveTo

Copy a file.

File.Copy

FileInfo.CopyTo

Get the size of a file.

FileInfo.Length

Get the attributes of a file.

File.GetAttributes

Set the attributes of a file.

File.SetAttributes

Determine if a file exists.

File.Exists

Read from a binary file.

How to: Read and Write to a Newly Created Data File

Write to a binary file.

How to: Read and Write to a Newly Created Data File

Create a directory.

CreateDirectory

Directory

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:\temp\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));
            }
        }
    }
}

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

class Test
{
    public static void main(String[] args)
    {
        String path = "c:\\temp\\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

Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

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