Android如何设置两个view的Z order？

有的时候想让一个view出现在另一个view的上面，可以这样：

You can't use a LinearLayout for this, but you can use a FrameLayout. In a FrameLayout, the z-index is defined by the order in which the items are added, for example:

<FrameLayout
    xmlns:andro
        />
</FrameLayout>

In this instance, the TextView would be drawn on top of the ImageView, along the bottom center of the image.