How to hide the actionbar before the Activity is loaded?

try this in manifest file

<activity
        android:name="yourActivityName"
        android:label="your label"
        android:theme="@android:style/Theme.Holo.Light.NoActionBar.Fullscreen" >

    </activity>

Check this link Android: hide action bar while view load

Code snippets from the link, incase the link breaks down, courtesy @kleopatra:

Setting the properties windowNoTitle to true on your theme will hide the ActionBar. use two different themes both extending parent="Theme.AppCompat.Light" in order to prevent NPE when using getSupportActionBar

set the styles as

<style name="AppThemeNoBar" parent="Theme.AppCompat.Light">
        <item name="android:windowNoTitle">true</item>
</style>
<style name="AppThemeBar" parent="Theme.AppCompat.Light">
        <item name="android:windowNoTitle">false</item>
</style>

Due to some odd behaviour on versions < 11, you need to add

if (Build.VERSION.SDK_INT < 11){ getSupportActionBar().hide(); }

inside activities that do not need the actionbar