使用HttpWebRequest连接HTTP服务判断是否连通，各种异常啊！

Question

public void TryConnectByHttpRequest()         {             HttpWebRequest httpReq = null;             try             {                 if (!string.IsNullOrEmpty(this.servUrl))                 {                     string param = "test1=zh-CN&test2=request";                     byte[] data = Encoding.ASCII.GetBytes(param);                       httpReq = (HttpWebRequest)HttpWebRequest.Create(this.servUrl);                     httpReq.Method = "POST";//不用Post用Get某些Http服务会报错：远程服务器返回错误: (411) 所需的长度。                     httpReq.ContentType = "application/x-www-form-urlencoded;charset=gb2312";                     httpReq.ContentLength = data.Length;                     //忽略缓存，完全使用服务器满足请求                     httpReq.CachePolicy = new RequestCachePolicy(RequestCacheLevel.NoCacheNoStore);                     //响应延时为4S                     httpReq.Timeout = 4000;                     //这个在Post的时候，一定要加上，如果服务器返回错误，他还会继续再去请求，不会使用之前的错误数据，做返回数据                     httpReq.ServicePoint.Expect100Continue = false;                     httpReq.ServicePoint.ConnectionLimit = 500;                       using (Stream reqStream = httpReq.GetRequestStream())                     {                         reqStream.Write(data, 0, data.Length);                     }                       IAsyncResult result = httpReq.BeginGetResponse(new AsyncCallback(RespCallback), httpReq);                       int DefaultTimeout = 2 * 60 * 1000; // 2 minutes timeout                     ThreadPool.RegisterWaitForSingleObject(result.AsyncWaitHandle, new WaitOrTimerCallback(TimeoutCallback), httpReq, DefaultTimeout, true);                 }             }             catch (WebException ex)             {                 FrmMain.Instance.WriteClientLog("尝试连接Web服务出现异常：" + ex.Message);             }         }           public void TryConnectByHttpRequestGet()         {             HttpWebRequest httpReq = null;             try             {                 if (!string.IsNullOrEmpty(this.servUrl))                 {                     httpReq = (HttpWebRequest)HttpWebRequest.Create(this.servUrl);                     httpReq.Method = "GET";                     httpReq.ContentType = "application/x-www-form-urlencoded;charset=gb2312";                     //忽略缓存，完全使用服务器满足请求                     httpReq.CachePolicy = new RequestCachePolicy(RequestCacheLevel.NoCacheNoStore);                     //响应延时为4S                     httpReq.Timeout = 4000;                       IAsyncResult result = httpReq.BeginGetResponse(new AsyncCallback(RespCallback), httpReq);                       int DefaultTimeout = 2 * 60 * 1000; // 2 minutes timeout                     ThreadPool.RegisterWaitForSingleObject(result.AsyncWaitHandle, new WaitOrTimerCallback(TimeoutCallback), httpReq, DefaultTimeout, true);                 }             }             catch (WebException ex)             {                 FrmMain.Instance.WriteClientLog("尝试连接Web服务出现异常：" + ex.Message);             }         }   上面写的两个方法分别是用的Post 和Get请求！   客户公司提供了HTTP服务 我用Post方法正常连通 Get方法异常:远程服务器返回错误: (411) 所需的长度。 我自己用HttpListener写的Http服务 我用Post方法异常：操作超时 Get方法正常连通。   为啥会出现不同的情况啊？还有一般去请求HTTP到底是用Get还是Http啊？

Answer 1

从名称上看，大致上，我们通常这样分：如果是从服务器下载数据，一般用GET（获取的意思），如果是从客户端提交数据，一般用POST（提交的意思） 当然，这两者并没有明确的界限。获取数据也可以用POST，提交数据也可以用GET（如果提交的数据为简单数据的话）

Answer 2

你可要从服务上获取数据，使用get方法，要制定获取数据的长度，要不然服务器不知道你要获取多少。