Hey guys,

I've got a main class and a second class that handles an object within the main class. The second class needs to manipulate the layout of the main class (changing background images of objects), but the findViewById() function is returning null every time. The second class isn't a new Activity (at least, I don't think it should be), so I'm pretty sure I don't want to call setContentView(R.layout.main) in the second class, since the main class is an activity with that View.

Here's what I have:

Code: Select all

public class MainClass extends Activity {

public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        SubClass item = new SubClass(this);
   }

}

And then the other class is:

Code: Select all

public class Dice extends View  {
        public Dice(Context context){
      super(context);
      img1 = (ImageView)findViewById(R.id.img1);
   }
}

There is more to the code, but these are the relevant bits. The img1 is always null, no matter what I do.

Ideas?

I'm fairly new to droid, so I can't promise I'll be tons of help.

Essentially, what I think is going on is that you Dice class has no reference to your main.xml. It's not enough for the two files to be in the same package, the class has to call the xml. I'm unaware of a way to reference a layout with out calling setContentView(R.layout.main); but that doesn't mean that one doesn't exist.

My only suggestions would be to either pass changes you want to make back to your MainClass and actually do them there, or call your images that are instantiated in the MainClass from your Dice class.

I hope that's even kind of helpful!

You need to inflate the view main.xml use Layout Inflater so that findViewById won't return null. Hopefully that helps