.NET处理HTTP请求

第一种：使用HttpWebRequest

string result = "";
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(httpUrl);
            request.Method = "POST";
            request.ContentType = "application/json";
            string data = "{
"header": {
"token": "30xxx6aaxxx93ac8cxx8668xx39xxxx",
"username": "jdads",
"password": "liuqiangdong2010",
"action": ""
},
"body": {}
}";
            data = jsonData;
            byte[] byteData = Encoding.UTF8.GetBytes(data.ToString());
            request.ContentLength = byteData.Length;

            using (Stream postStream = request.GetRequestStream())
            {
                postStream.Write(byteData, 0, byteData.Length);
            }
            try
            {
                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)
                {
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    result = reader.ReadToEnd();
                    Console.WriteLine(result);

                }
            }
            

第二种：WebClient，也过时了：
第三种：HttpClient 当前主流用法，异步请求，自.NET4.5开始可从Nuget包管理中获取。

 static async Task<Product> GetProductAsync(string path)
        {
            Product product = null;
            HttpResponseMessage response = await client.GetAsync(path);
            if (response.IsSuccessStatusCode)
            {
                product = await response.Content.ReadAsAsync<Product>();
            }
            return product;
        }

第四种：第三方类库：

RestSharp

REST API请求测试类库，可通过 NuGet 获得。

Flurl.Http

最新的便捷的api测试工具，使用HttpClient实现，可通过 NuGet 安装。

参考

Call a Web API From a .NET Client (C#)