SslStream.EndRead(IAsyncResult) 方法

定義

命名空間:

System.Net.Security

組件:

System.Net.Security.dll

來源:

SslStream.cs

結束由先前呼叫 BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) 所開始的非同步讀取作業。

public:
 override int EndRead(IAsyncResult ^ asyncResult);

public override int EndRead (IAsyncResult asyncResult);

override this.EndRead : IAsyncResult -> int

Public Overrides Function EndRead (asyncResult As IAsyncResult) As Integer

參數

asyncResult

IAsyncResult

IAsyncResult 執行個體，由對 BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) 的呼叫所傳回。

傳回

Int32

Int32 值，指定從基礎資料流中讀取的位元組數。

例外狀況

ArgumentNullException

asyncResult 為 null。

ArgumentException

asyncResult 不是由呼叫 BeginRead(Byte[], Int32, Int32, AsyncCallback, Object) 的方式所建立。

InvalidOperationException

不存在要完成的暫止讀取作業。

-或-

尚未執行驗證。

IOException

讀取作業失敗。

範例

下列程式代碼範例示範結束異步讀取作業。

static void ReadCallback( IAsyncResult^ ar )
{
   
   // Read the  message sent by the server.
   // The end of the message is signaled using the
   // "<EOF>" marker.
   SslStream^ stream = dynamic_cast<SslStream^>(ar->AsyncState);
   int byteCount = -1;
   try
   {
      Console::WriteLine( L"Reading data from the server." );
      byteCount = stream->EndRead( ar );
      
      // Use Decoder class to convert from bytes to UTF8
      // in case a character spans two buffers.
      Decoder^ decoder = Encoding::UTF8->GetDecoder();
      array<Char>^chars = gcnew array<Char>(decoder->GetCharCount( buffer, 0, byteCount ));
      decoder->GetChars( buffer, 0, byteCount, chars, 0 );
      readData->Append( chars );
      
      // Check for EOF or an empty message.
      if ( readData->ToString()->IndexOf( L"<EOF>" ) == -1 && byteCount != 0 )
      {
         
         // We are not finished reading.
         // Asynchronously read more message data from  the server.
         stream->BeginRead( buffer, 0, buffer->Length, gcnew AsyncCallback( ReadCallback ), stream );
      }
      else
      {
         Console::WriteLine( L"Message from the server: {0}", readData );
      }
   }
   catch ( Exception^ readException ) 
   {
      e = readException;
      complete = true;
      return;
   }

   complete = true;
}

static void ReadCallback(IAsyncResult ar)
{
    // Read the  message sent by the server.
    // The end of the message is signaled using the
    // "<EOF>" marker.
    SslStream stream = (SslStream) ar.AsyncState;
    int byteCount = -1;
    try
    {
        Console.WriteLine("Reading data from the server.");
        byteCount = stream.EndRead(ar);
        // Use Decoder class to convert from bytes to UTF8
        // in case a character spans two buffers.
        Decoder decoder = Encoding.UTF8.GetDecoder();
        char[] chars = new char[decoder.GetCharCount(buffer,0, byteCount)];
        decoder.GetChars(buffer, 0, byteCount, chars,0);
        readData.Append (chars);
        // Check for EOF or an empty message.
        if (readData.ToString().IndexOf("<EOF>") == -1 && byteCount != 0)
        {
            // We are not finished reading.
            // Asynchronously read more message data from  the server.
            stream.BeginRead(buffer, 0, buffer.Length,
                new AsyncCallback(ReadCallback),
                stream);
        }
        else
        {
            Console.WriteLine("Message from the server: {0}", readData.ToString());
        }
    }
    catch (Exception readException)
    {
        e = readException;
        complete = true;
        return;
    }
    complete = true;
}

Shared Sub ReadCallback(ar As IAsyncResult)
    ' Read the  message sent by the server.
    ' The end of the message is signaled using the
    ' "<EOF>" marker.
    Dim stream = CType(ar.AsyncState, SslStream)
    Dim byteCount As Integer
    Try
        Console.WriteLine("Reading data from the server.")
        byteCount = stream.EndRead(ar)
        ' Use Decoder class to convert from bytes to UTF8
        ' in case a character spans two buffers.
        Dim decoder As Decoder = Encoding.UTF8.GetDecoder()
        Dim chars = New Char(decoder.GetCharCount(buffer, 0, byteCount)) {}
        decoder.GetChars(buffer, 0, byteCount, chars, 0)
        readData.Append(chars)
        ' Check for EOF or an empty message.
        If readData.ToString().IndexOf("<EOF>") = -1 AndAlso byteCount <> 0 Then
            ' We are not finished reading.
            ' Asynchronously read more message data from  the server.
            stream.BeginRead(buffer, 0, buffer.Length, New AsyncCallback(AddressOf ReadCallback), stream)
        Else
            Console.WriteLine("Message from the server: {0}", readData.ToString())
        End If
    Catch readException As Exception
        e = readException
        complete = True
        Return
    End Try
    complete = True
End Sub

備註

如果作業尚未完成，這個方法會封鎖直到它完成為止。

若要同步執行這項作業，請使用 Read 方法。

在成功驗證之前，您無法呼叫此方法。 若要驗證呼叫其中AuthenticateAsClient一個、 或 BeginAuthenticateAsClient、 AuthenticateAsServerBeginAuthenticateAsServer 方法。