This is **best & easy** way to hide default action bar from android activity.
Put these two styles in `res>values>styles.xml`. You may already have `AppTheme`
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
<style name="AppTheme.NoActionBar" parent="AppTheme">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
and in your manifest class
<activity
android:name=".YourActivityName"
android:theme="@style/AppTheme.NoActionBar">
</activity>
If you just want a theme with no action bar you can use 'NoActionBar' variant, for eg. if your base theme is as below
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
then you can use
<style name="AppThemeNoActionBar" parent="Theme.AppCompat.Light.NoActionBar">
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
</style>
But if you want to retain the properties of your main theme i.e. AppTheme you can do as below
<style name="AppThemeNoActionBar" parent="AppTheme">
<item name="windowActionBar">false</item>
<item name="windowNoTitle">true</item>
</style>
You can retain all the properties of your base theme this way and don't have to explicitly add them in your NoActionBar theme :)
