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

This error message is typically caused by trying to call the setImageResource() method on an ImageView object that has not been initialized yet.

To resolve this error, you should make sure that you have properly initialized the ImageView object before trying to call any of its methods. This can be done by calling findViewById() to get a reference to the ImageView in your layout file and assigning it to a variable.

For example, if your ImageView has an id of "my_image_view" in your layout file, you could initialize it like this:

ImageView myImageView = findViewById(R.id.my_image_view);

Once you have properly initialized the ImageView object, you should be able to call its setImageResource() method without encountering the null object reference error.