网络编程采用HttpClient类更好

一般人网络编程普遍用HttpWebRequest，类似下面的实现。我也一般都这样实现

 string result = string.Empty;
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(new Uri(requesturl));
                request.Method = method; 
                request.ContentType = "application/json";
                request.Headers["Authorization"] = AuthStr;
                if (!string.IsNullOrWhiteSpace(jsonstr))
                {
                    using (var requestStream = await request.GetRequestStreamAsync())
                    {
                        var writer = new StreamWriter(requestStream);
                        writer.Write(jsonstr);
                        writer.Flush();
                    }
                }
                using (var resp = await request.GetResponseAsync())
                {
                    using (var responseStream = resp.GetResponseStream())
                    {
                        var reader = new StreamReader(responseStream);
                        result = reader.ReadToEnd();
                    }
                }
                return result;

　　但微软建议采用System.Net.Http.HttpClient类：MSDN链接

使用HttpClient类的确是比较简洁了。

 System.Net.Http.HttpClient client = new System.Net.Http.HttpClient();
                client.DefaultRequestHeaders.Authorization =
                    new AuthenticationHeaderValue("Bearer",AuthStr);
                HttpContent content = new StringContent(jsonstr,Encoding.UTF8);
                content.Headers.ContentType.CharSet = null;
                content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/json");
                System.Net.Http.HttpResponseMessage response = await client.PutAsync(new Uri(requesturl), content);
                response.EnsureSuccessStatusCode();
                string responseBody = System.Text.RegularExpressions.Regex.Unescape(await response.Content.ReadAsStringAsync());
                return responseBody;