activity theme
<style name="DialogTransparent" parent="Theme.AppCompat.Light.NoActionBar">
<item name="android:windowNoTitle">true</item>
<item name="android:windowIsFloating">true</item>
<item name="android:windowBackground">@android:color/transparent</item>
</style>
让activity全屏显示
getWindow().setLayout(ViewGroup.LayoutParams.MATCH_PARENT,ViewGroup.LayoutParams.MATCH_PARENT);
这行代码必须在setContentView后设置
