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Android

Posted by Farouk Charkas
Farouk Charkas
1,957 Points

Why is my app crashing again? Help appreciated!

This is the part that is crashing:

//What will happen
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.inject(this);
        ImageButton advancedButton = (ImageButton) findViewById(R.id.advancedButton);

        View.OnClickListener listener = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                setContentView(R.layout.advanced);
            }
        };

        advancedButton.setOnClickListener(listener);

        ImageButton imageButtonRip = (ImageButton) findViewById(R.id.imageButtonRip);
        View.OnClickListener mamans = new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                setContentView(R.layout.activity_main);
            }
        };

        imageButtonRip.setOnClickListener(mamans);

    }
Farouk Charkas
Farouk Charkas
1,957 Points

This is my logcat, the caused by part:

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageButton.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
            at everingapplications.blue_jay.MainActivity.onCreate(MainActivity.java:90)
Farouk Charkas
Farouk Charkas
1,957 Points

Any ideas why Jon Kussmann and Gloria Dwomoh

1 Answer

Jon Kussmann
PLUS
Jon Kussmann
Courses Plus Student 7,254 Points
Jon Kussmann
Jon Kussmann
Courses Plus Student 7,254 Points

You are asking your Activity to find R.id.imageButtonRip while the layout is still R.layout.activity_main. You didn't post your layout files, but I imagine that button only exists in the layout R.layout.advanced

Is there a reason why you aren't just switch activities instead of attempting to change the layout of one activity?

Farouk Charkas
Farouk Charkas
1,957 Points

To be honest Jon Kussmann,

I really do not know. Bu it works! Thank you so so much! I do have a bug, I can only do it once, but that is okay!