调用接口 （带参）

public string httpposturlxm()
{
string strURL = "http://www.baidu.com";
System.Net.HttpWebRequest request;
request = (System.Net.HttpWebRequest)WebRequest.Create(strURL);
//Post请求方式
request.Method = "POST";
// 内容类型
request.ContentType = "application/x-www-form-urlencoded";
// 参数经过URL编码
string paraUrlCoded = System.Web.HttpUtility.UrlEncode("jsonData");
paraUrlCoded += "=" + System.Web.HttpUtility.UrlEncode("{ \"sysApiKey\":\"加密账号\",\"documentId\":\"文档id，查询该文档id对应的提交批次的数据处理情况\"}");
byte[] payload;
//将URL编码后的字符串转化为字节
payload = System.Text.Encoding.UTF8.GetBytes(paraUrlCoded);
//设置请求的 ContentLength
request.ContentLength = payload.Length;
//获得请 求流
System.IO.Stream writer = request.GetRequestStream();
//将请求参数写入流
writer.Write(payload, 0, payload.Length);
// 关闭请求流
writer.Close();
System.Net.HttpWebResponse response;
// 获得响应流
response = (System.Net.HttpWebResponse)request.GetResponse();
System.IO.StreamReader myreader = new System.IO.StreamReader(response.GetResponseStream(), Encoding.UTF8);
string responseText = myreader.ReadToEnd();
myreader.Close();
return responseText;

}