不能在WPF项目中使用“this”关键字或某些对象（预期的标识符）

I have a WPF project. When I add a class and a method, and write "this.", I get no intellisense. There is a message in the bottom tab of Visual Studio that an identifier is expected, but that doesn't make sense.I have a WPF project. When I add a class and a