【转】C#模拟http 发送post或get请求

原文地址：http://www.cnblogs.com/xssxss/archive/2012/07/03/2574554.html

模拟POST Json

public static string PostMoths(string url, string param)
{
string strURL = url;
System.Net.HttpWebRequest request;
request = (System.Net.HttpWebRequest)WebRequest.Create(strURL);
request.Method = "POST";
request.ContentType = "application/json;charset=UTF-8";
string paraUrlCoded = param;
byte[] payload;
payload = System.Text.Encoding.UTF8.GetBytes(paraUrlCoded);
request.ContentLength = payload.Length;
Stream writer = request.GetRequestStream();
writer.Write(payload, 0, payload.Length);
writer.Close();
System.Net.HttpWebResponse response;
response = (System.Net.HttpWebResponse)request.GetResponse();
System.IO.Stream s;
s = response.GetResponseStream();
string StrDate = "";
string strValue = "";
StreamReader Reader = new StreamReader(s, Encoding.UTF8);
while ((StrDate = Reader.ReadLine()) != null)
{
strValue += StrDate + "\r\n";
}
return strValue;
}

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