在app/src/main/res/values/styles.xml中设置AppTheme主题
<style name="AppTheme" parent="Theme.AppCompat.Light.NoActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
在app/AndroidManifest.xml的application标签中应用此主题
android:theme="@style/AppTheme"
