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FileWebRequest::BeginGetRequestStream Method

Begins an asynchronous request for a Stream object to use to write data.

Namespace:  System.Net
Assembly:  System (in System.dll)

[HostProtectionAttribute(SecurityAction::LinkDemand, ExternalThreading = true)]
virtual IAsyncResult^ BeginGetRequestStream(
	AsyncCallback^ callback, 
	Object^ state
) override


Type: System::AsyncCallback
The AsyncCallback delegate.
Type: System::Object
An object that contains state information for this request.

Return Value

Type: System::IAsyncResult
An IAsyncResult that references the asynchronous request.


The Method property is GET and the application writes to the stream.


The stream is being used by a previous call to BeginGetRequestStream.


No write stream is available.


The FileWebRequest was aborted.

The BeginGetRequestStream method starts an asynchronous request for a stream used to send data to a file system resource. The callback method that implements the AsyncCallback delegate uses the EndGetRequestStream method to return the request stream.


The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The following code example uses BeginGetRequestStream to make an asynchronous request for a Stream object.

public ref class RequestDeclare
   FileWebRequest^ myFileWebRequest;
   String^ userinput;
      myFileWebRequest = nullptr;


ref class FileWebRequest_reqbeginend
   static ManualResetEvent^ allDone = gcnew ManualResetEvent( false );
   static void ReadCallback( IAsyncResult^ ar )

         // State of the request is asynchronous.
         RequestDeclare^ requestDeclare = dynamic_cast<RequestDeclare^>(ar->AsyncState);
         FileWebRequest^ myFileWebRequest = requestDeclare->myFileWebRequest;
         String^ sendToFile = requestDeclare->userinput;

         // End the Asynchronus request by calling the 'EndGetRequestStream()' method.
         Stream^ readStream = myFileWebRequest->EndGetRequestStream( ar );

         // Convert the String* into Byte array.
         ASCIIEncoding^ encoder = gcnew ASCIIEncoding;
         array<Byte>^byteArray = encoder->GetBytes( sendToFile );

         // Write to the stream.
         readStream->Write( byteArray, 0, sendToFile->Length );
         Console::WriteLine( "\nThe String you entered was successfully written into the file." );
         Console::WriteLine( "\nPress Enter to continue." );
      catch ( ApplicationException^ e ) 
         Console::WriteLine( "ApplicationException is : {0}", e->Message );



int main()
   array<String^>^args = Environment::GetCommandLineArgs();
   if ( args->Length < 2 )
      Console::WriteLine( "\nPlease enter the file name as command line parameter:" );
      Console::WriteLine( "Usage:FileWebRequest_reqbeginend <systemname>/<sharedfoldername>/<filename>\n" );
      Console::WriteLine( "Example:FileWebRequest_reqbeginend shafeeque/shaf/hello.txt" );

         // Place a webrequest.
         WebRequest^ myWebRequest = WebRequest::Create( String::Concat( "file://", args[ 1 ] ) );

         // Create an instance of the 'RequestDeclare' and associate the 'myWebRequest' to it.
         RequestDeclare^ requestDeclare = gcnew RequestDeclare;
         requestDeclare->myFileWebRequest = dynamic_cast<FileWebRequest^>(myWebRequest);

         // Set the 'Method' property of 'FileWebRequest' Object* to 'POST' method.
         requestDeclare->myFileWebRequest->Method = "POST";
         Console::WriteLine( "Enter the String* you want to write into the file:" );
         requestDeclare->userinput = Console::ReadLine();

         // Begin the Asynchronous request for getting file content using 'BeginGetRequestStream()' method .
         IAsyncResult^ r = dynamic_cast<IAsyncResult^>(requestDeclare->myFileWebRequest->BeginGetRequestStream( gcnew AsyncCallback( &FileWebRequest_reqbeginend::ReadCallback ), requestDeclare ));
      catch ( ProtocolViolationException^ e ) 
         Console::WriteLine( "ProtocolViolationException is : {0}", e->Message );
      catch ( InvalidOperationException^ e ) 
         Console::WriteLine( "InvalidOperationException is : {0}", e->Message );
      catch ( UriFormatException^ e ) 
         Console::WriteLine( "UriFormatExceptionException is : {0}", e->Message );


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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