Attempt to invoke virtual method 'void android.widget.Button.setVisibility(int)' on a null object reference

Question

I have set the visibilty for button as "gone" but now when i want to set button visible , Getting following error while trying to set visibility for button

    @Bind(R.id.btn1)
    Button btn1;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        View view = inflater.inflate(R.layout.hifragment_main, container, false);

      if(1==1) 
        {
            btn1.setVisibility(View.VISIBLE);
        }
        return view;
    }

Answer 1

you didn't initialize you button, please initialize it as below,

View view = inflater.inflate(R.layout.hifragment_main, container, false);
btn1 = (Button) view.findViewById(R.id.btn1);

Answer 2

You need to initialize your button object.

btn1 = (Button) findViewById(R.id.your_btn_id);

Then you can check if (btn1 != null)

Answer 3

for example if you are in mainActivity : in onCreate method:

if you don't use setcontentView here, it will give you nullException

setContentView(R.layout.activity_main);

and then

btn =findViewById(R.id.btn); btn.setVisibility(View.VISIBLE);