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HttpListener::GetContext Method

Waits for an incoming request and returns when one is received.

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

public:
HttpListenerContext^ GetContext()

Return Value

Type: System.Net::HttpListenerContext
An HttpListenerContext object that represents a client request.

ExceptionCondition
HttpListenerException

A Win32 function call failed. Check the exception's ErrorCode property to determine the cause of the exception.

InvalidOperationException

This object has not been started or is currently stopped.

-or-

The HttpListener does not have any Uniform Resource Identifier (URI) prefixes to respond to. See Remarks.

ObjectDisposedException

This object is closed.

Before calling this method, you must call the Start method and add at least one URI prefix to listen for by adding the URI strings to the HttpListenerPrefixCollection returned by the Prefixes property. For a detailed description of prefixes, see the HttpListener class overview.

This method blocks while waiting for an incoming request. If you want incoming requests to be processed asynchronously (on separate threads) so that your application does not block, use the BeginGetContext method.

Notes to Callers

This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in the .NET Framework.

The following code example demonstrates calling this method.

// This example requires the System and System.Net namespaces. 
public static void SimpleListenerExample(string[] prefixes)
{
    if (!HttpListener.IsSupported)
    {
        Console.WriteLine ("Windows XP SP2 or Server 2003 is required to use the HttpListener class.");
        return;
    }
    // URI prefixes are required, 
    // for example "http://contoso.com:8080/index/".
    if (prefixes == null || prefixes.Length == 0)
      throw new ArgumentException("prefixes");

    // Create a listener.
    HttpListener listener = new HttpListener();
    // Add the prefixes. 
    foreach (string s in prefixes)
    {
        listener.Prefixes.Add(s);
    }
    listener.Start();
    Console.WriteLine("Listening...");
    // Note: The GetContext method blocks while waiting for a request. 
    HttpListenerContext context = listener.GetContext();
    HttpListenerRequest request = context.Request;
    // Obtain a response object.
    HttpListenerResponse response = context.Response;
    // Construct a response. 
    string responseString = "<HTML><BODY> Hello world!</BODY></HTML>";
    byte[] buffer = System.Text.Encoding.UTF8.GetBytes(responseString);
    // Get a response stream and write the response to it.
    response.ContentLength64 = buffer.Length;
    System.IO.Stream output = response.OutputStream;
    output.Write(buffer,0,buffer.Length);
    // You must close the output stream.
    output.Close();
    listener.Stop();
}

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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