C# 调用WebApi出现 远程服务器返回错误: (500) 内部服务器错误

一、检查错误错误

将 HttpWebResponse response = (HttpWebResponse)request.GetResponse();
改为   HttpWebResponse response;
            try
            {
                response = (HttpWebResponse)request.GetResponse();
            }
            catch (WebException ex)
            {
                response = (HttpWebResponse)ex.Response;
            }
           

二、解决问题

如果抛出异常出现为：找到了与该请求匹配的多个操作

则修改WebApi中的路由

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