Android_ui之View与ViewGroup

在Android APP中，所有的用户界面元素都是由View和ViewGroup的对象构成的。View是绘制在屏幕上的用户能与之交互的一个对象。而ViewGroup则是一个用于存放其他View（和ViewGroup）对象的布局容器。、

下面是Android文档提供的关于View的介绍：

public class

View

extends Object

implements Drawable.Callback KeyEvent.Callback AccessibilityEventSource

java.lang.Object
↳	android.view.View

Known Direct Subclasses AnalogClock, ImageView, KeyboardView, MediaRouteButton, ProgressBar, Space, SurfaceView, TextView, TextureView, ViewGroup, ViewStub

Known Indirect Subclasses AbsListView, AbsSeekBar, AbsSpinner, AbsoluteLayout, AdapterView<T extends Adapter>, AdapterViewAnimator, AdapterViewFlipper, and 56 others. 下面是Android文档提供的关于ViewGroup的介绍： public abstract class ViewGroup extends View implements ViewManager ViewParent java.lang.Object    ↳ android.view.View      ↳ android.view.ViewGroup Known Direct Subclasses AbsoluteLayout, AdapterView<T extends Adapter>, DrawerLayout, FragmentBreadCrumbs, FrameLayout, GridLayout, LinearLayout, PagerTitleStrip, RelativeLayout,SlidingDrawer, SlidingPaneLayout, ViewPager Known Indirect Subclasses AbsListView, AbsSpinner, AdapterViewAnimator, AdapterViewFlipper, AppWidgetHostView, CalendarView, DatePicker, DialerFilter, ExpandableListView, and 21 others. 知道这些就行了，剩下的看文档就OK了。