FloatingActionButton
1.P424页的<android.support.design.widget.FloatingActionButton/>应当修改为<com.google.android.material.floatingactionbutton.FloatingActionButton/>
2.P424页的悬浮按钮的src属性所选取的图片应该要来自layout或者drawable文件夹中,否则会报错
CoordinatorLayout
1.应该将FrameLayout替换成<androidx.coordinatorlayout.widget.CoordinatorLayout/>