public class DataRequest

{

    public string paramData=string.Empty;//请求参数

    public string resData=string.Empty;//返回值

    public HttpStatusCode statusCode;//状态记录

    public Exception errorAsync;//记录异步函数中的错误

    public static Encoding dataEncode = Encoding.UTF8;//字符编码方式为UTF8

    public void RequestURL(string url)

    {

        HttpWebRequest webReq = (HttpWebRequest)WebRequest.Create(new Uri(url));

        webReq.Method = "POST";

        webReq.ContentType = "application/x-www-form-urlencoded";

        webReq.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), webReq);

    }

    private void GetRequestStreamCallback(IAsyncResult asynchronousResult)

    {

        try

        {

            HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;

            Stream postStream = request.EndGetRequestStream(asynchronousResult);

            byte[] byteArray = dataEncode.GetBytes(paramData);

            postStream.Write(byteArray, 0, byteArray.Length);

            postStream.Close();

            request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request);

        }

        catch (Exception ee)

        {

            errorAsync = ee;

         }

    }

    private void GetResponseCallback(IAsyncResult asynchronousResult)

    {

        try

        {

            HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;

            HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);

            Stream streamResponse = response.GetResponseStream();

            StreamReader streamRead = new StreamReader(streamResponse);

            statusCode=response.StatusCode;

            resData = streamRead.ReadToEnd();

            streamResponse.Close();

  &nb