FileWebRequest.EndGetRequestStream(IAsyncResult) 方法

定义

结束对 Stream 实例的异步请求,应用程序使用该实例写入数据。

public:
 override System::IO::Stream ^ EndGetRequestStream(IAsyncResult ^ asyncResult);
public override System.IO.Stream EndGetRequestStream (IAsyncResult asyncResult);
override this.EndGetRequestStream : IAsyncResult -> System.IO.Stream
Public Overrides Function EndGetRequestStream (asyncResult As IAsyncResult) As Stream

参数

asyncResult
IAsyncResult

引用对流的挂起请求的 IAsyncResult

返回

应用程序用于写入数据的 Stream 对象。

例外

asyncResultnull

示例

以下示例使用 EndGetRequestStream 方法结束对 Stream 对象的异步请求。

public ref class RequestDeclare
{
public:
   FileWebRequest^ myFileWebRequest;
   String^ userinput;
   RequestDeclare()
   {
      myFileWebRequest = nullptr;
   }

};

ref class FileWebRequest_reqbeginend
{
public:
   static ManualResetEvent^ allDone = gcnew ManualResetEvent( false );
   static void ReadCallback( IAsyncResult^ ar )
   {
      try
      {
         
         // 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 );
         readStream->Close();
         allDone->Set();
         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" );
   }
   else
   {
      try
      {
         
         // 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 ));
         FileWebRequest_reqbeginend::allDone->WaitOne();
         Console::Read();
      }
      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 );
      }

   }
}

public class RequestDeclare
{
     public FileWebRequest myFileWebRequest;	
     public String userinput;

    public RequestDeclare()
    {
        myFileWebRequest = null;
    }
}

class FileWebRequest_reqbeginend
{
    public static ManualResetEvent allDone = new ManualResetEvent(false);

    static void Main(string[] args)
    {
      if (args.Length < 1)
      {
        Console.WriteLine("\nPlease enter the file name as command line parameter:");
           Console.WriteLine("Usage:FileWebRequest_reqbeginend <systemname>/<sharedfoldername>/<filename>\nExample:FileWebRequest_reqbeginend shafeeque/shaf/hello.txt");
      }
      else
      {

        try
         {

              // Place a webrequest.
              WebRequest myWebRequest= WebRequest.Create("file://"+args[0]);
        
              // Create an instance of the 'RequestDeclare' and associate the 'myWebRequest' to it.		
              RequestDeclare requestDeclare = new RequestDeclare();
              requestDeclare.myFileWebRequest = (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=(IAsyncResult) requestDeclare.myFileWebRequest.BeginGetRequestStream(new AsyncCallback(ReadCallback),requestDeclare);			
              allDone.WaitOne();

              Console.Read();
        }
        catch(ProtocolViolationException e)
        {
              Console.WriteLine("ProtocolViolationException is :"+e.Message);
        }
        catch(InvalidOperationException e)
        {
            Console.WriteLine("InvalidOperationException is :"+e.Message);
        }
        catch(UriFormatException e)
        {
            Console.WriteLine("UriFormatExceptionException is :"+e.Message);
         }
     }
    }

    private static void ReadCallback(IAsyncResult ar)
    {	

     try
  {

          // State of the request is asynchronous.
          RequestDeclare requestDeclare=(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 = new ASCIIEncoding();
          byte[] byteArray = encoder.GetBytes(sendToFile);
        
          // Write to the stream.
          readStream.Write(byteArray,0,sendToFile.Length);
          readStream.Close();
          allDone.Set();
            
          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 :"+e.Message);
      }				
    }
Public Class RequestDeclare
    Public myFileWebRequest As FileWebRequest
    Public userinput As [String]
    
    
    Public Sub New()
        myFileWebRequest = Nothing
    End Sub
End Class


Class FileWebRequest_reqbeginend
    Public Shared allDone As New ManualResetEvent(False)
    
    ' Entry point which delegates to C-style main Private Function.
    Public Overloads Shared Sub Main()
        Main(System.Environment.GetCommandLineArgs())
    End Sub
    
    
    Overloads Shared Sub Main(args() As String)
        If args.Length < 2 Then
            Console.WriteLine(ControlChars.Cr + "Please enter the file name as command line parameter:")
            Console.WriteLine("Usage:FileWebRequest_reqbeginend <systemname>/<sharedfoldername>/<filename>")
        Console.WriteLine("Example: FileWebRequest_reqbeginend shafeeque/shaf/hello.txt")
        
        Else
            Try

                ' Place a webrequest.
                Dim myWebRequest As WebRequest = WebRequest.Create(("file://" + args(1)))
                
                ' Create an instance of the 'RequestDeclare' and associate the 'myWebRequest' to it.		
                Dim requestDeclare As New RequestDeclare()
                requestDeclare.myFileWebRequest = CType(myWebRequest, FileWebRequest)
                ' 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 .
                Dim r As IAsyncResult = CType(requestDeclare.myFileWebRequest.BeginGetRequestStream(AddressOf ReadCallback, requestDeclare), IAsyncResult)
                allDone.WaitOne()
                
                Console.Read()
            Catch e As ProtocolViolationException
                Console.WriteLine(("ProtocolViolationException is :" + e.Message))
            Catch e As InvalidOperationException
                Console.WriteLine(("InvalidOperationException is :" + e.Message))
            Catch e As UriFormatException
                Console.WriteLine(("UriFormatExceptionException is :" + e.Message))
            End Try

        End If 
    End Sub
    
    
    Private Shared Sub ReadCallback(ar As IAsyncResult)
        Try

            ' State of the request is asynchronous.
            Dim requestDeclare As RequestDeclare = CType(ar.AsyncState, RequestDeclare)
            Dim myFileWebRequest As FileWebRequest = requestDeclare.myFileWebRequest
            Dim sendToFile As [String] = requestDeclare.userinput
            
            ' End the Asynchronus request by calling the 'EndGetRequestStream()' method.
            Dim readStream As Stream = myFileWebRequest.EndGetRequestStream(ar)
            
            ' Convert the string into byte array.
            Dim encoder As New ASCIIEncoding()
            Dim byteArray As Byte() = encoder.GetBytes(sendToFile)
            
            ' Write to the stream.
            readStream.Write(byteArray, 0, sendToFile.Length)
            readStream.Close()
            allDone.Set()

            
            Console.WriteLine(ControlChars.Cr +"The String you entered was successfully written into the file.")
            Console.WriteLine(ControlChars.Cr +"Press Enter to continue.")

            Catch e As ApplicationException
            Console.WriteLine(("ApplicationException is :" + e.Message))
        End Try

    End Sub

注解

方法 EndGetRequestStream 完成由 BeginGetRequestStream 方法启动的异步流请求。

注意

若要避免垃圾回收的计时问题,请务必通过在调用 方法后对 方法返回GetResponseStream的流调用 Close 方法来关闭响应流EndGetResponse

适用于

另请参阅