类分层结构
- java.lang.Object
- android.view.View (implements android.view.accessibility.AccessibilityEventSource, android.graphics.drawable.Drawable.Callback, android.view.KeyEvent.Callback)
- android.view.ViewGroup (implements android.view.ViewManager, android.view.ViewParent)
- android.widget.RelativeLayout
枚举分层结构
- java.lang.Object
- java.lang.Enum<E> (implements java.lang.Comparable<T>, java.io.Serializable)