場景重構

  public ActionResult Index(string ucode)
        {
            string userInfo = GetUserInfo(ucode).Result;
            ViewData["UserInfo"] = userInfo;
            return View();
        }

        // 這樣調用死鎖
        async Task<string> GetUserInfo(string ucode)
        {
            HttpClient client = new HttpClient();
            var httpContent = new FormUrlEncodedContent(new Dictionary<string, string>()
            {
                {"ucode", ucode}
            });
            string uri = "http://www.xxxx.com/user/get";
            var response = await client.PostAsync(uri, httpContent);
            return response.Content.ReadAsStringAsync().Result;
        }

解決方案

        // 其他網友的解決方案
        // 也是有問題的
        async Task<string> GetUserInfo1(string ucode)
        {
            HttpClient client = new HttpClient();
            var httpContent = new FormUrlEncodedContent(new Dictionary<string, string>()
            {
                {
 
"ucode", ucode}
            });
            string uri = "http://www.xxxx.com/user/get";
            var response = client.PostAsync(uri, httpContent).Result.Content.ReadAsStringAsync().Result;
            return response;
        }


        // 最終解決方案
        string GetUserInfo2(string ucode)
        {
            HttpClient client 
 
= new HttpClient();
            var httpContent = new FormUrlEncodedContent(new Dictionary<string, string>()
            {
                {"ucode", ucode}
            });
            string uri = "http://www.xxxx.com/user/get";
            var response = client.PostAsync(uri, httpContent).ConfigureAwait(false).GetAwaiter().GetResult().Content.ReadAsStringAsync().ConfigureAwait(false).GetAwaiter().GetResult();
            return response;
        }

參考 網址: https://stackoverflow.com/questions/10004697/calling-configureawait-from-an-asp-net-mvc-action

async、await在ASP.NET[ MVC]中之線程死鎖的故事