C#模拟http 发送post或get请求的简单实例

private string HttpPost(string Url, string postDataStr)
   {
     HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
     request.Method = "POST";
     request.ContentType = "application/x-www-form-urlencoded";
     request.ContentLength = Encoding.UTF8.GetByteCount(postDataStr);
     request.CookieContainer = cookie;
     Stream myRequestStream = request.GetRequestStream();
     StreamWriter myStreamWriter = new StreamWriter(myRequestStream, Encoding.GetEncoding("gb2312"));
     myStreamWriter.Write(postDataStr);
     myStreamWriter.Close();

HttpWebResponse response = (HttpWebResponse)request.GetResponse();

response.Cookies = cookie.GetCookies(response.ResponseUri);
     Stream myResponseStream = response.GetResponseStream();
     StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
     string retString = myStreamReader.ReadToEnd();
     myStreamReader.Close();
     myResponseStream.Close();

return retString;
   }

public string HttpGet(string Url, string postDataStr)
   {
     HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url + (postDataStr == "" ? "" : "?") + postDataStr);
     request.Method = "GET";
     request.ContentType = "text/html;charset=UTF-8";

HttpWebResponse response = (HttpWebResponse)request.GetResponse();
     Stream myResponseStream = response.GetResponseStream();
     StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
     string retString = myStreamReader.ReadToEnd();
     myStreamReader.Close();
     myResponseStream.Close();

return retString;
   }

在post的时候有时也用的到cookie，像登录163发邮件时候就需要发送cookie，所以在外部一个cookie属性随时保存 CookieContainer cookie = new CookieContainer();

注意：有时候请求会重定向，但我们就需要从重定向url获取东西，像QQ登录成功后获取sid，但上面的会自动根据重定向地址跳转。我们可以用：

request.AllowAutoRedirect = false;设置重定向禁用，你就可以从headers的Location属性中获取重定向地址