Android Trivial knowledge points collection

1. Recently discovered the V7 package after the Android Studio update, each time the activity was created automatically inherited by the appcompatactivity, very uncomfortable, or accustomed to activity. There's nothing wrong with that. After all, Google's new bag. But one of them still affects me. If you inherit appcompatactivity, the hidden title bar will be invalidated. That code doesn't work and causes a crash . This.requestwindowfeature (window.feature_no_title); I do not know why, I have to re-inherit the activity. Paste the method of how to change the default inheritance appcompatactivity, Someone else wrote it.

Android Trivial knowledge points collection