C# HTTP请求 异步,async await

        static void Main(string[] args)
        {
            new Task(() =>
            {
                Invoke();
            }).Start();
            Console.WriteLine("我是主线程");
            Console.ReadKey();
        }

        public static async void Invoke()
        {
            var result = Keep();
            Console.WriteLine("执行其他的");
            string str = await result;  //等待返回
            Console.WriteLine(str);  //输出返回
        }

        public static async Task<string> Keep()
        {
            HttpWebRequest request = WebRequest.Create("http:/*****************") as HttpWebRequest;
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded; charset=UTF-8";     //这里一定不要忘记了 我排查了好久 发现这里没有写这一句  弄的怀疑人生了 后来通过抓包对比 才发现这个差距  粗心了
            string data = "user;
            byte[] buf = System.Text.Encoding.GetEncoding("UTF-8").GetBytes(data);
            request.ContentLength = buf.Length;
            Stream newStream = request.GetRequestStream();
            newStream.Write(buf, 0, buf.Length);
            newStream.Close();
            HttpWebResponse response = await request.GetResponseAsync() as HttpWebResponse;
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("UTF-8"));
            string result = reader.ReadToEnd();
            return result;
        }

 如果你不写 request.ContentType 那么用下面的这种也可以

        static void Main(string[] args)
        {
            new Task(() =>
            {
                Invoke();
            }).Start();
            Console.WriteLine("我是主线程");
            Console.ReadKey();
        }

        public static async void Invoke()
        {
            var result = Keep();
            Console.WriteLine("执行其他的");
            string str = await result;  //等待返回
            Console.WriteLine(str);  //输出返回
        }

        public static async Task<string> Keep()
        {
            string url = "http://message.sungoin.com/platform-message/getPlatformClientMsg";
            string data = "user;
            url = url + "?" + data;
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "POST";
            HttpWebResponse response = await request.GetResponseAsync() as HttpWebResponse;
            StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding("UTF-8"));
            string result = reader.ReadToEnd();
            return result.ToString();
        }

  ============================================2020年6月28日再次编辑=========================================================

今天看到一篇异步请求的文章,然后点进去一看,发现是自己写的,这感觉有点怪异,

然后我决定更新一下这个博客吧,都2020了,还用老版本的那种写法,很麻烦的。本来也是很简单的东西,但是看着别扭。

HttpClient 的异步操作 还是写一下吧! 现在谁还用HttpWebRequest 写起来麻烦的要死
public async Task<string> Post()
{
  HttpClient httpClient=new HttpClient();
  HttpContent httpContent = new StringContent("");
   var response = await httpClient.PostAsJsonAsync(url, httpContent);
  var content = await response.Content.ReadAsStringAsync();
  httpContent.Dispose();
return content;
}
public async Task<string> Get()
{
  HttpClient httpClient=new HttpClient();
   var response = await httpClient.GetStringAsync(url);
  httpContent.Dispose();
}

这段代码与上面还有有区别的
区别在于,上述部分是直接一个线程,由这个线程去进行http请求,来达到异步的效果
这一段呢!是这个http请求这一个过程异步。
这边就不写具体验证代码了。
public async string Post()
{
  HttpClient httpClient=new HttpClient();
  HttpContent httpContent = new StringContent("");
   var response = httpClient.PostAsJsonAsync(url, httpContent);
  var content = response.Content.ReadAsStringAsync();
  httpContent.Dispose();
return content;
}
非异步