I know this question has been asked million times but whichever method I use is not good for me.
If I use
android:theme="@android:style/Theme.NoTitleBar"
in the manifest file, the whole theme of the app changes. If I put
requestWindowFeature(Window.FEATURE_NO_TITLE);
in the onCreate activities, it shows up shortly when starting an app.
Btw I don't have any theme selected, just using standard android.
It is unclear what you mean by "whole theme of app changes". For API Level 11+ devices, you probably should be using @android:style/Theme.Holo.NoActionBar
.