android - 什么是 View 层次结构？

Question

我是学android的，当然是新手，老是看view hierarchy之类的，请问这到底是什么意思呢？什么是 View 层次结构？例如

// fragment's containing frame doesn't exist. The fragment // may still be created from its saved state, but there is // no reason to try to create its view hierarchy because it // won't be displayed. Note this is not needed -- we could // just run the code below, where we would create and return // the view hierarchy; it would just never be used.

http://developer.android.com/reference/android/app/Fragment.html

Answer 1

View 在另一个 View 中创建一个层次结构，外部 View 成为内部 View 的父 View ，内部 View 是其 subview 。它只是嵌套 View 。

这是一个例子: