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SslStream.EndRead Method

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


Type: System.IAsyncResult
An IAsyncResult instance returned by a call to BeginRead

Return Value

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


asyncResult is null.


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;

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.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.