hi, I'm working in a project which need to show my MainActivity after i run several java class. i need to run bluetooth> register > MainActivity. MainActivity is the only activity that contain layout. because Bluetooth and register doesn't have layout, i deleted this and ;. I also put intent in my program to refer one activity to another. After that i change my AndroidManifest stuctured like this :
after i open the program, it shut down immediately. can you tell me how to switch activity properly without android launcher shooting down? thank you for your help.
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.append(java.lang.CharSequence)' on a null object reference