当尝试使用mysql创建asp.net webapi时，会发生超时异常

Question

我尝试通过连接mysql创建一个asp.net webapi。添加了所有mysql引用。我尝试http://localhost:22522/api/Values/1，然后得到一个错误，如下图所示。我不知道哪里出错了？谁能帮我。

webapi config：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Web.Http;
using Microsoft.Owin.Security.OAuth;
using Newtonsoft.Json.Serialization;
using MySql.Data.MySqlClient;

namespace webapp
{
    public static class WebApiConfig
    {
        public static MySqlConnection conn()
        {
            string conn_string = "server=localhost; port=8080; database=all_users; Uid=root; Pwd =123;";
            MySqlConnection conn = new MySqlConnection(conn_string);
            return conn;
        }
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services
            // Configure Web API to use only bearer token authentication.
            config.SuppressDefaultHostAuthentication();
            config.Filters.Add(new HostAuthenticationFilter(OAuthDefaults.AuthenticationType));

            // Web API routes
            config.MapHttpAttributeRoutes();

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }
    }
}

价值控制器：

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Net;
    using System.Net.Http;
    using System.Web.Http;
    using MySql.Data.MySqlClient;


    namespace webapp.Controllers
    {
        public class ValuesController : ApiController
        {
            public class result
            {
                public string username { get; set; }
                public string password { get; set; }
                public string error { get; set; }

                public result(string username, string password, string error)
                {
                    this.username = username;
                    this.password = password;
                    this.error = error;
                }
            }

            // GET api/values/5
            public List<result> Get(int id)
            {
                MySqlConnection conn = WebApiConfig.conn();
                MySqlCommand query = conn.CreateCommand();
                query.CommandText = "SELECT username, password  From users";
                var result = new List<result>();

                try
                {
                    conn.Open();
                }
                catch (MySql.Data.MySqlClient.MySqlException ex)
                {
                    result.Add(new result(null, null, ex.ToString()));
                }
                MySqlDataReader fetch_query = query.ExecuteReader();

                while (fetch_query.Read())
                {
                    result.Add(new result(fetch_query["username"].ToString(), fetch_query["password"].ToString(), null));
                }
                return result;
            }
        }
    }

的web.config：

 <connectionStrings>
    <add name="conn_string" connectionString="server=localhost; port:8080; User Id=root;database=all_users;password=123" providerName="MySql.Data.MySqlClient"/>
  </connectionStrings>

DB：

错误：