C# 发送Post请求（带参数）

此处内容传输都是用UTF-8编码

1.不带参数发送Post请求

        /// <summary>
        /// 指定Post地址使用Get 方式获取全部字符串
        /// </summary>
        /// <param name="url">请求后台地址</param>
        /// <returns></returns>
        public static string Post(string url)
        {
            string result = "";
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "POST";
            HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
            Stream stream = resp.GetResponseStream();
            //获取内容
            using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
            {
                result = reader.ReadToEnd();
            }
            return result;
        }

2.带参数Post请求,指定键值对

        /// <summary>
        /// 指定Post地址使用Get 方式获取全部字符串
        /// </summary>
        /// <param name="url">请求后台地址</param>
        /// <returns></returns>
        public static string Post(string url,Dictionary<string,string> dic)
        {
            string result = "";
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            #region 添加Post 参数
            StringBuilder builder = new StringBuilder();
            int i = 0;
            foreach (var item in dic)
            {
                if (i > 0)
                    builder.Append("&");
                builder.AppendFormat("{0}={1}", item.Key, item.Value);
                i++;
            }
            byte[] data = Encoding.UTF8.GetBytes(builder.ToString());
            req.ContentLength = data.Length;
            using (Stream reqStream = req.GetRequestStream())
            {
                reqStream.Write(data, 0, data.Length);
                reqStream.Close();
            }
            #endregion
            HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
            Stream stream = resp.GetResponseStream();
            //获取响应内容
            using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
            {
                result = reader.ReadToEnd();
            }
            return result;
        }

3.带参数的Post请求，指定发送字符串内容

/// <summary>
/// 指定Post地址使用Get 方式获取全部字符串
/// </summary>
/// <param name="url">请求后台地址</param>
/// <param name="content">Post提交数据内容(utf-8编码的)</param>
/// <returns></returns>
public static string Post(string url, string content)
{
    string result = "";
    HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
    req.Method = "POST";
    req.ContentType = "application/x-www-form-urlencoded";
 
    #region 添加Post 参数
    byte[] data = Encoding.UTF8.GetBytes(content);
    req.ContentLength = data.Length;
    using (Stream reqStream = req.GetRequestStream())
    {
        reqStream.Write(data, 0, data.Length);
        reqStream.Close();
    }
    #endregion
 
    HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
    Stream stream = resp.GetResponseStream();
    //获取响应内容
    using (StreamReader reader = new StreamReader(stream, Encoding.UTF8))
    {
        result = reader.ReadToEnd();
    }
    return result;
}

转载方法：

 HttpWebRequest req = (HttpWebRequest)HttpWebRequest.Create("http://fanyi.baidu.com/transcontent");
            Encoding encoding = Encoding.UTF8;
            string param = "ie=utf-8&source=txt&query=hello&t=1327829764203&token=8a7dcbacb3ed72cad9f3fb079809a127&from=auto&to=auto";
            //encoding.GetBytes(postData);
            byte[] bs = Encoding.ASCII.GetBytes(param);
            string responseData = String.Empty;            
            req.Method = "POST";
            req.ContentType = "application/x-www-form-urlencoded";
            req.ContentLength = bs.Length;
            using (Stream reqStream = req.GetRequestStream())
            {
                reqStream.Write(bs, 0, bs.Length);
                reqStream.Close();
            }
            using (HttpWebResponse response = (HttpWebResponse)req.GetResponse())
            {
                using (StreamReader reader = new StreamReader(response.GetResponseStream(),encoding))
                {
                    responseData = reader.ReadToEnd().ToString();
                }
                context.Response.Write(responseData);
            }

4.发送get请求

 public static string Get(string Url)
        {
            //System.GC.Collect();
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(Url);
            request.Proxy = null;
            request.KeepAlive = false;
            request.Method = "GET";
            request.ContentType = "application/json; charset=UTF-8";
            request.AutomaticDecompression = DecompressionMethods.GZip;

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream myResponseStream = response.GetResponseStream();
            StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.UTF8);
            string retString = myStreamReader.ReadToEnd();

            myStreamReader.Close();
            myResponseStream.Close();

            if (response != null)
            {
                response.Close();
            }
            if (request != null)
            {
                request.Abort();
            }

            return retString;
        }

5.发送json内容和header设置

 private void postjson()
    {
        string RobotID = Web.DLL.Utility.RequestUtility.GetString("RobotID");//header
        string phoneNumber = Web.DLL.Utility.RequestUtility.GetString("phoneNumber");
        int remainingTime_min = Web.DLL.Utility.RequestUtility.GetInt("remainingTime_min", 0);

        string url = "https://lsrobottest.lscure.com:1800/Robot/WebDeviceInfo";
        //Hashtable hash_json = new Hashtable();
        //hash_json.Add("phoneNumber", phoneNumber);
        //hash_json.Add("remainingTime_min", remainingTime_min);


        string hash_json = "{\"phoneNumber\": \"" + phoneNumber + "\",\"remainingTime_min\": " + remainingTime_min + "}";

        Hashtable hash_header = new Hashtable();
        hash_header.Add("RobotID", RobotID);
        Response.Write(PostJson(url, hash_json.ToString(), hash_header));
        Response.End();
    }
    private string PostJson(string url, string postData, Hashtable headht = null)
    {
        //https的需要加着两行----------------
        ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls;
        ServicePointManager.SecurityProtocol = (SecurityProtocolType)192 | (SecurityProtocolType)768 | (SecurityProtocolType)3072;
        //------------------

        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        request.Method = "POST";
        request.ContentType = "application/json;charset=UTF-8";
        request.Accept = "application/json";

        #region headers设置
        if (headht != null)
        {
            foreach (DictionaryEntry item in headht)
            {
                request.Headers.Add(item.Key.ToString(), item.Value.ToString());
            }
        }
        #endregion

        byte[] paramJsonBytes;
        paramJsonBytes = System.Text.Encoding.UTF8.GetBytes(postData);
        request.ContentLength = paramJsonBytes.Length;
        Stream writer;
        try
        {
            writer = request.GetRequestStream();
        }
        catch (Exception e)
        {
            writer = null;
            Response.Write("连接服务器失败:" + e.ToString());
            Response.End();
        }
        writer.Write(paramJsonBytes, 0, paramJsonBytes.Length);
        writer.Close();
        HttpWebResponse response;
        try
        {
            response = (HttpWebResponse)request.GetResponse();
        }
        catch (WebException ex)
        {
            response = ex.Response as HttpWebResponse;
        }
        Stream resStream = response.GetResponseStream();
        StreamReader reader = new StreamReader(resStream);
        string text = reader.ReadToEnd();
        return text;
    }

6.腾讯文档里的用例：

private const string sContentType = "application/x-www-form-urlencoded";
        private const string sUserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";
        public static string Send(string data, string url)
        {
            return Send(Encoding.GetEncoding("UTF-8").GetBytes(data), url);
        }

        public static string Send(byte[] data, string url)
        {
            Stream responseStream;
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            if (request == null)
            {
                throw new ApplicationException(string.Format("Invalid url string: {0}", url));
            }
            // request.UserAgent = sUserAgent;  
            request.ContentType = sContentType;
            request.Method = "POST";
            request.ContentLength = data.Length;
            Stream requestStream = request.GetRequestStream();
            requestStream.Write(data, 0, data.Length);
            requestStream.Close();
            try
            {
                responseStream = request.GetResponse().GetResponseStream();
            }
            catch (Exception exception)
            {
                throw exception;
            }

            string str = string.Empty;
            using (StreamReader reader = new StreamReader(responseStream, Encoding.GetEncoding("UTF-8")))
            {
                str = reader.ReadToEnd();
            }
            responseStream.Close();
            return str;
        }

方法调用：

 Hashtable hash = new Hashtable();
        Web.DLL.wxItem.userlist u = islogin();
        if (u != null)
        {
            string page_url = Web.DLL.Utility.RequestUtility.GetString("page_url");
            WX_About wa = new WX_About();
            string access_token = wa.getaccess_token(1);
            string url = "https://api.weixin.qq.com/wxa/genwxashortlink?access_token=" + access_token;
            string returnStr = HttpUtil.Send("{\"page_url\": \"" + page_url + "\"}", url);
            errorclass errmode = JsonConvert.DeserializeObject<errorclass>(returnStr);
            if (errmode.ErrCode == 0)
            {
                hash["error"] = 0;
                hash["errorstr"] = "获取成功";
                hash["data"] = returnStr;
            }
            else
            {
                hash["error"] = 1;
                hash["data"] = returnStr;
                hash["errorstr"] = "获取失败";
            }
        }
        else
        {
            hash["error"] = -1;
            hash["errorstr"] = "请先登录";
        }
        Response.Write(JsonMapper.ToJson(hash));
        Response.End();

7.post传递参数：request.ContentType = "application/x-www-form-urlencoded";

 SortedDictionary<string, string> inputPara = new SortedDictionary<string, string>();
                            inputPara.Add("pid", "1017");
                            inputPara.Add("method", "app");
                            inputPara.Add("type", "alipay");
                            inputPara.Add("out_trade_no", orderno);
                            inputPara.Add("notify_url", GlobalData.SiteURL + "/pay_buyer_back_juhe.aspx");
                            inputPara.Add("return_url", "www");
                            inputPara.Add("name", "订单支付");
                            inputPara.Add("money", so.payprice.ToString());
                            inputPara.Add("clientip", HttpContext.Current.Request.UserHostAddress);//
                            //inputPara.Add("param", "order," + u.id);
                            inputPara.Add("timestamp", getTimestamp_ten());
                            inputPara.Add("sign_type", "RSA");

                            Dictionary<string, string> sPara = new Dictionary<string, string>();
                            //过滤空值、sign与sign_type参数
                            sPara = Core.FilterPara(inputPara);
                            //获取待签名字符串
                            string preSignStr = Core.CreateLinkString(sPara);

                            string sign_get = Sign2(preSignStr, appkey_juhe, "utf-8");


                            inputPara.Add("sign", sign_get);

                            string prepayXml = Post("https://szsc.chennels.cn/api/pay/create", inputPara);

 private string Sign2(string dataToSign, string privateKey, string _input_charset)
    {
        //转换成适用于.Net的秘钥
        var netKey = RSAPrivateKeyJava2DotNet(privateKey);
        var rsa = new RSACryptoServiceProvider();
        rsa.FromXmlString(netKey);

        //签名返回
        using (var sha256 = new SHA256CryptoServiceProvider())
        {
            var signData = rsa.SignData(Encoding.UTF8.GetBytes(dataToSign), sha256);
            return Convert.ToBase64String(signData);
        }



    }

 private string getTimestamp_ten()
    {
        long timestamp = (long)(DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc)).TotalSeconds;
        return timestamp.ToString().Substring(0, 10);
    }

private string Post(string url, SortedDictionary<string, string> dic)
    {
        string postData = "";// "key1=value1&key2=value2";

        StringBuilder builder = new StringBuilder();
        int i = 0;
        foreach (var item in dic)
        {
            if (i > 0)
                builder.Append("&");
            builder.AppendFormat("{0}={1}", item.Key, System.Web.HttpUtility.UrlEncode(item.Value, Encoding.UTF8));//这个地方要进行编码，否则传不过去
            i++;
        }
        postData = builder.ToString();


        ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
        request.Method = "POST";
        request.ContentType = "application/x-www-form-urlencoded";
        request.ContentLength = postData.Length;

        StreamWriter requestWriter = new StreamWriter(request.GetRequestStream(), Encoding.ASCII);
        requestWriter.Write(postData);
        requestWriter.Close();

        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
        StreamReader responseReader = new StreamReader(response.GetResponseStream());
        string responseData = responseReader.ReadToEnd();
        responseReader.Close();
        response.Close();

        Console.WriteLine(responseData);

        return responseData;
    }