从 web api 使用 post 方法时出错答案

【问题标题】：Error while consuming post method from web api从 web api 使用 post 方法时出错
【发布时间】：2021-06-02 22:29:45
【问题描述】：

这是我正在创建团队的 web api 方法的完整代码，我正在客户端中使用此方法。我已经通过 /api/Team/insertTeam 测试了这个发布方法，它在数据库中添加了新团队，但是在使用 httpclient/ 时出错了

    [HttpPost]
            [Route("insertTeam")]
            public int insertTeam(Team team)
            {
                int teamid = -1;
                try
                {
                    using (SqlConnection con = new SqlConnection(ConString))
                    {
                        con.Open();
                        using (SqlCommand cmd = new SqlCommand("dbo.Team", con))
                        {
                            cmd.CommandText = "INSERT INTO team(Score, wideball, Noball, name, wickets, overs) VALUES(@score, @wideball, @noball, @name, @wickets, @overs); SELECT SCOPE_IDENTITY()";
    
                            cmd.Parameters.AddWithValue("@score", team.Score);
                            cmd.Parameters.AddWithValue("@wideball", team.Wideball);
                            cmd.Parameters.AddWithValue("@noball", team.Noball);
                            cmd.Parameters.AddWithValue("@name", team.Name);
                            cmd.Parameters.AddWithValue("@wickets", team.Wickets);
                            cmd.Parameters.AddWithValue("@overs", team.Overs);
    
                            teamid = Convert.ToInt32(cmd.ExecuteScalar());
                            con.Close();
                        }
                    }
                }
                catch (SqlException e)
                {
                    System.Diagnostics.Debug.WriteLine("\n----------Error-----------\n");
                    System.Diagnostics.Debug.WriteLine(e.Message);
                }
                return teamid;
            }

客户项目代码

    private void AddTeam()
                            {
                                HttpClient client = new HttpClient();
                                client.BaseAddress = new Uri("http://localhost:44382/api/Team");
                                //Adding teams
                                Team team1 = new Team
                                {
                                    Name = tbteam1.Text,
                                    Score = 0,
                                    Wideball = 0,
                                    Noball = 0,
                                    Wickets = 0,
                                    Overs = 0,
                                };
                                Team team2 = new Team
                                {
                                    Name = tbteam2.Text,
                                    Score = 0,
                                    Wideball = 0,
                                    Noball = 0,
                                    Wickets = 0,
                                    Overs = 0,
                                };
    
    
                                MediaTypeFormatter[] formatter = new MediaTypeFormatter[] { new JsonMediaTypeFormatter() };
                                HttpContent content = new ObjectContent<Team>(team1, formatter[0]);
                                HttpResponseMessage response = client.PostAsync(client.BaseAddress + "/insertTeam", content).Result;
    
    }

客户端代码中的 postAsync 方法出错

System.AggregateException
  HResult=0x80131500
  Message=One or more errors occurred.
  Source=mscorlib
  StackTrace:
   at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
   at System.Threading.Tasks.Task`1.GetResultCore(Boolean waitCompletionNotification)
   at System.Threading.Tasks.Task`1.get_Result()
   at Client.team.AddTeam() in K:\LiveScoreSystemWebApi\Client\team.aspx.cs:line 259
   at Client.team.GoBtn_Click(Object sender, EventArgs e) in K:\LiveScoreSystemWebApi\Client\team.aspx.cs:line 51

  This exception was originally thrown at this call stack:
    [External Code]

Inner Exception 1:
HttpRequestException: An error occurred while sending the request.

Inner Exception 2:
WebException: The underlying connection was closed: An unexpected error occurred on a receive.

Inner Exception 3:
IOException: Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

Inner Exception 4:
SocketException: An existing connection was forcibly closed by the remote host

【问题讨论】：

错误很明显，即使代码不是，并且包含几个错误。 HTTP 连接突然关闭。至于代码 a) 看起来没有错误处理。您发布的内容类似于应用程序崩溃时写入 Windows 事件日志的事件。您需要添加适当的错误处理和日志记录。 b）您正在使用带有异步方法的.Result。不要那样做。使用async/await。将方法的签名更改为async Task AddTeam()。 c) 代码在每次调用时创建一个新的 HttpClient 实例。 HttpClient 意味着可以重用，即使是来自多个线程
服务器是否在有机会响应甚至发送 500 错误之前就崩溃了？
在邮递员中工作但在客户端中无效
还有其他解决办法吗？？

标签： c# asp.net-web-api

【解决方案1】：

只需将基本地址 https 从 http..!!

【讨论】：

这个答案被版主标记为低质量。我认为这没问题，但也许您可以添加更多关于为什么 https 起作用而不是 http 的详细信息，以帮助未来的读者。

【解决方案2】：

试试这个代码：


public  async Task PostData
{   
                                var team1 = new Team
                                {
                                    Name = tbteam1.Text,
                                    Score = 0,
                                    Wideball = 0,
                                    Noball = 0,
                                    Wickets = 0,
                                    Overs = 0,
                                };
                             

 using var client = new HttpClient();
 client.BaseAddress = new  Uri("http://localhost:44382/api/Team");
 var contentType = new MediaTypeWithQualityHeaderValue("application/json");
client.DefaultRequestHeaders.Accept.Add(contentType);
var stringData = JsonConvert.SerializeObject(team1);
contentData = new StringContent(stringData, Encoding.UTF8, "application/json");
var response = await client.PostAsync(client.BaseAddress + "/insertTeam", contentData);
.....
}

【讨论】：

Exception throw: 'System.Threading.ThreadAbortException' in mscorlib.dll 这个错误也存在
您能否显示调用您的 addteam 方法的代码。请问？
protected void GoBtn_Click(object sender, EventArgs e) { AddTeamAsync(); Response.Redirect("toss.aspx"); }