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SslStream.EndRead Method

Note: This method is new in the .NET Framework version 2.0.

Ends an asynchronous read operation started with a previous call to BeginRead.

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

public override int EndRead (
	IAsyncResult asyncResult
public int EndRead (
	IAsyncResult asyncResult
public override function EndRead (
	asyncResult : IAsyncResult
) : int



An IAsyncResult instance returned by a call to BeginRead

Return Value

A Int32 value that specifies the number of bytes read from the underlying stream.

Exception typeCondition


asyncResult is a null reference (Nothing in Visual Basic).


asyncResult was not created by a call to BeginRead.


There is no pending read operation to complete.


The read operation failed.


Authentication has not occurred.

If the operation has not completed, this method blocks until it does.

To perform this operation synchronously, use the Read method.

You cannot call this method until you have successfully authenticated. To authenticate call one of the AuthenticateAsClient, or BeginAuthenticateAsClient, AuthenticateAsServer, BeginAuthenticateAsServer methods.

The following code example demonstrates ending an asynchronous read operation.

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;
        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),
            Console.WriteLine("Message from the server: {0}", readData.ToString());
    catch (Exception readException)
        e = readException;
        complete = true;
    complete = true;

Windows 98, Windows 2000 SP4, Windows Millennium Edition, 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