Cant use button in fragment and app not working when generating an apk file

Question

I am developing an application with navigation drawer activity, using the default options in android studio, and then i created fragments and linked it to the navigation activity.

Now, I want to use a button in that fragment and clicking that button will have to open an activity, but I can't achieve this.

The onclicklistener, switch case ,i tried everything but none of them working when i click the button the application just stopped working

And the another problem is that, the whole application just crashes if i generate this as an apk and use it in a real device ,while this was working fine with an emulator.

Help me with this

Answer 1

Thanks for your time:

I just solved the issue, as being a beginner I forgot to mention my activity in the manifest file, after adding that to the manifest file its working fine now.