为什么 "no http resource was found that matches the request URI"？

Question

大家好，我试着用 ssms 和 visual studio 制作了一个 api。我看到了一个教程，虽然我的步骤完全正确，但它返回给我 "no http resource was found that matches the request URI":

我的控制器中有这样的代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using EmployeeDataAccess;

namespace EmployeeService1.Controllers
{
    public class EmployeeController : ApiController
    {
        public IEnumerable<Signage> Get()
        {
            using (Raw_DataEntities entities = new Raw_DataEntities())
            {
                return entities.Signages.ToList();
            }
        }

        public Signage Get(int fid)
        {
            using (Raw_DataEntities entities = new Raw_DataEntities())
            {
                return entities.Signages.FirstOrDefault(e => e.FID == fid);
            }
        }
    }
}

WebApiConfig

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;

namespace EmployeeService2
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {
            // Web API configuration and services

            // Web API routes
            config.MapHttpAttributeRoutes();

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

我做错了什么？当我尝试在指定的本地主机中进行路由时，它 returns 我是这样的：

System.InvalidOperationException HResult=0x80131509 Message=在应用程序配置文件中找不到名为 'Raw_DataEntities' 的连接字符串。 来源= 堆栈跟踪：

Answer 1

您 web.config 缺少名为 'Raw_DataEntities' 的连接字符串，将其添加到您的数据库，它应该可以工作。

<connectionStrings>
  <add name="Raw_DataEntities" connectionString="<your connection string" />
</connectionStrings>