/// <summary>
/// 异步方式发起http get请求
/// </summary>
/// <param name="url">包含QueryString的URL</param>
/// <param name="callback">结束后的回调</param>
/// <returns>请求是否发出，异常时返回false</returns>
public bool HttpGet(string url, AsyncHttpCallback callback)
{
var webRequest = CreateRequest(url, HttpMethod.GET);
try
{
var state = new RequestState { AsyncCallBack = callback, Request = webRequest };
IAsyncResult result = webRequest.BeginGetResponse(ResponseCallback, state);
// this line implements the timeout, if there is a timeout, the callback fires and the request becomes aborted
ThreadPool.RegisterWaitForSingleObject(result.AsyncWaitHandle, TimeoutCallback, webRequest, RequestTimeout, true);
// The response came in the allowed time. The work processing will happen in the callback function.
AllDone.WaitOne();
// Release the HttpWebResponse resource.
state.Response.Close();
}
catch
{
return false;
//throw;
}
return true;
}
/// <summary>
/// 异步方式发起http post请求
/// </summary>
/// <param name="url"></param>
/// <param name="postData"></param>
/// <param name="callback"></param>
/// <returns></returns>
public bool HttpPost(string url, string postData, AsyncHttpCallback callback)
{
StreamWriter requestWriter = null;
StreamReader responseReader = null;
string responseData = null;
var webRequest = CreateRequest(url, HttpMethod.POST);
webRequest.ContentType = "application/x-www-form-urlencoded";
try
{
//POST the data.
requestWriter = new StreamWriter(webRequest.GetRequestStream());
requestWriter.Write(postData);
requestWriter.Close();
requestWriter = null;
var state = new RequestState { AsyncCallBack = callback, Request = webRequest };
IAsyncResult result = webRequest.BeginGetResponse(ResponseCallback, state);
// this line implements the timeout, if there is a timeout, the callback fires and the request becomes aborted
ThreadPool.RegisterWaitForSingleObject(result.AsyncWaitHandle, TimeoutCallback, webRequest,
RequestTimeout, true);
// The response came in the allowed time. The work processing will happen in the
// callback function.
AllDone.WaitOne();
// Release the HttpWebResponse resource.
state.Response.Close();
}
catch
{
return false;
//throw;
}
finally
{
if (requestWriter != null)
requestWriter.Close();
}
return true;
}
private void FireCallback(RequestState state)
{
//call back
if (state.AsyncCallBack != null)
{
state.AsyncCallBack(this, state.RequestData.ToString());
}
}