Fragment implements the function of the bottom menu bar - imitating WeChat

Fragment implements the bottom menu bar, which has less sliding function than WeChat.

1. Realize the effect

Click the option at the bottom of the page to switch Fragments.

2. Project directory

1> A MainActivity.java, corresponding to the layout file activity_main.xml. activity_main.xml is divided into two parts, FrameLayout and the bottom menu bar (layout_bottom.xml).

2> Four Fragments and their corresponding layout files

3> The 4 icons in the bottom menu bar and the 4 icons that turn green after clicking are stored in the drawable. Made by ImageAsset.

3. Specific implementation

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearL