HttpResponse.WriteFile Method (String, Int64, Int64)

Writes the specified file directly to an HTTP response output stream.

Namespace: System.Web
Assembly: System.Web (in system.web.dll)

Public Sub WriteFile ( _
	filename As String, _
	offset As Long, _
	size As Long _
Dim instance As HttpResponse
Dim filename As String
Dim offset As Long
Dim size As Long

instance.WriteFile(filename, offset, size)
public void WriteFile (
	String filename, 
	long offset, 
	long size
public function WriteFile (
	filename : String, 
	offset : long, 
	size : long



The name of the file to write to the HTTP output stream.


The byte position in the file where writing will start.


The number of bytes to write to the output stream.

When this method is used with large files, calling the method might result in an exception. The size of the file that can be used with this method depends on the hardware configuration of the Web server. For more information, see article 812406, "PRB: Response.WriteFile Cannot Download a Large File" in the Microsoft Knowledge Base.

The following example writes the entire contents of a text file named "login.txt" (which might contain literal text and HTML input controls) directly to the output stream.

Dim FileName As String
 Dim MyFileInfo As FileInfo
 Dim StartPos, FileSize As Long
 FileName = "c:\\temp\\login.txt"
 MyFileInfo = New FileInfo(FileName)
 FileSize = MyFileInfo.Length 
 Response.Write("Please Login: <br>")
 Response.WriteFile(FileName, StartPos, FileSize)

String fileName;
FileInfo myFileInfo;
long startPos = 0;
long fileSize;

fileName = "c:\\temp\\login.txt";
myFileInfo = new FileInfo(fileName);
fileSize = myFileInfo.get_Length();

get_Response().Write("Please Login: <br>");
get_Response().WriteFile(fileName, startPos, fileSize);

var fileName : String
var myFileInfo : FileInfo
var startPos : long = 0
var fileSize : long

fileName = "c:\\temp\\login.txt"
myFileInfo = new FileInfo(fileName)
fileSize = myFileInfo.Length 

Response.Write("Please Login: <br>")
Response.WriteFile(fileName, startPos, fileSize)

Windows 98, Windows 2000 SP4, 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

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