关于.net：多线程设计最佳实践

using System.Net; // need this somewhere

// need to declare an class so we can cast our state object back out
class RequestState {
    public WebRequest Request { get; set; }
}

static void Main( string[] args ) {
    // stupid cast neccessary to create the request
    HttpWebRequest request = WebRequest.Create("http://www.stackoverflow.com" ) as HttpWebRequest;

    request.BeginGetResponse(
        /* callback to be invoked when finished */
        (asyncResult) => {
            // fetch the request object out of the AsyncState
            var state = (RequestState)asyncResult.AsyncState;
            var webResponse = state.Request.EndGetResponse( asyncResult ) as HttpWebResponse;

            // there we go;
            Debug.Assert( webResponse.StatusCode == HttpStatusCode.OK );

            Console.WriteLine("Got Response from server:" + webResponse.Server );
        },
        /* pass the request through to our callback */
        new RequestState { Request = request }  
    );

    // blah
    Console.WriteLine("Waiting for response. Press a key to quit" );
    Console.ReadKey();
}