这两种语法有什么区别？

Question

android:textAppearance="@android:style/TextAppearance.Small"
android:textAppearance="?android:textAppearanceSmall"

两者都给出相同的结果。编译效率有什么区别吗

Answer 1

 android:textAppearance="@android:style/TextAppearance.Small"

是直接设置文字样式

android:textAppearance="?android:textAppearanceSmall"

是在此Activity或此TextView Theme上设置值的参考文本样式。像这样：

<style name="MyStyle">
<item name="textAppearanceSmall">@style/textStyle</item>
</style>