我收到此错误:
Error(3, 19) package android.app does not exist
Error(4, 18) package android.os does not exist
Error(6, 33) cannot find symbol
symbol: class Activity
Error(11, 26)cannot find symbol
symbol: class Bundle
Error(12, 9)cannot find symbol
symbol : variable super
Error(13, 9)cannot find symbol
symbol : method setContentView(int)
Error(10, 5)method does not override or implement a method from a supertype.
我知道我必须安装哪个库,但我对此感到困惑。
我该怎么做?我正在使用 osx
非常感谢。