写博客原因：添加了区域（用作后台）后,报错：

An unhandled exception occurred while processing the request.
AmbiguousActionException: Multiple actions matched. The following actions matched route data and had all constraints satisfied:

CompanyHome.Controllers.HomeController.Index (CompanyHome)
CompanyHome.Areas.Manage.Controllers.HomeController.Index (CompanyHome)

不是很明白，大概是找不到进入那个路由吧，命名空间冲突。

总览：

一.>>先在Startup.cs中添加对区域路由的路径，如图红框内

代码如下：

routes.MapRoute(

                    name: "areaname",

                    template: "{Manage:exists}/{controller=Home}/{action=Index}/{id?}");

                routes.MapAreaRoute(

                    name: "Manage",

                    areaName: "Manage",

                    template: "Manage/{controller=Home}/{action=Index}"

                    );

二.>>然后再给区域控制器添加如下：