Android Learning History-screen element hierarchy (View,viewgroup)

These days of study, often see View,viewgroup, and what Layoutinflater, and then look back at the original learned things.

Screen element hierarchyAndroid App Basic functional unit is activity-android.app.activity, an Activity can be a lot of things, but it does not exist on the screen itself. In order for your activity to have a screen display and be able to design her UI, you have to use the basic unit of the user interface expression on the views and viewgroups-android platform. Views

A view is an object in the base class Android.view.View. She is a data structure with properties that store content within a particular rectangular area of the layout and screen.

A view object that can handle measurements and layouts (I want to be the location of the layout to determine the meaning of it), draw, focus changes, scrolling, and on-screen gesture manipulation.

The view class is the base class for widgets-a complete set of well-implemented subclasses can draw the elements needed for screen interaction. Those Widgets (controls) handle their own measurements and drawings, so you can build your own UI more quickly. The available widgets include: Text,edittext,inputmethod,movementmethod,button,radiobutton ...

ViewGroup

A viewgroup is an object in the class Android.view.ViewGroup. As its name suggests, a viewgroup is a special type of view object, and her function is to include and manage the views and other viewgroups,viewgruop of its attribution to allow your UI to add structs (my understanding is nested ViewGroup), Create complex screen elements (that is, the view lot),

ViewGroup as the base class for layout-is also a complete set of well-implemented subclasses, providing a common type of screen layout. The layout is provided to you, and then you use the previous set of views to build your view structure.

A tree-structured UI

　　

Layoutparams:how A child specifies its POSITIOB and Size

Each ViewGroup class has an inner class that inherits Viewgroup.layoutparams.

Recommended links, said can also: http://byandby.iteye.com/blog/816718

Android Learning History-screen element hierarchy (View,viewgroup)