Java代码：
1 ) 定义 ViewStub
< ViewStub Android : id = "@+ id / stub _ import "
android : inflatedId ="@+ id / panel _ import "
android : layout ="@ layout / progress _ overlay "
android : layout _ width =" fill _ parent "
android:layout_height="wrap_content"
android:layout_gravity="bottom"/>
2 )展开视图
findViewById(R.id.stub_import).setVisibility(View.VISIBLE);
// 或者 获取视图
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