怎样把数据库文件.mdf和.ldf文件添加进入Visual Studio的“解决方案资源管理器”中？

1. If the App_Data folder doesn’t already exist, add the “App_Data” folder to your project. This can be done by selecting it from the “Add ASP.NET Folder” list or just adding a regular folder and naming it accordingly 2. Go to the course website a