GridLayout application

[ragnonerodocet]

Hi all, my first post!

I am working on a very simple project:

Only an Activity whit a GridLayout, a 3x3 matrix.

I have also created a custom Adaptor like this:

public View getView(int position, View convertView, ViewGroup parent) {
		ImageView imgV = new ImageView(myContext);
		imgV.setImageResource(R.drawable.icon);
		return imgV;
	}

that simply set an image on each cell.

Now I want to start with an empty grid, so I have deleted the line in which i set the image on every cell ('imgV.setImageResource(R.drawable.icon)').

Every 2 seconds, I want that a casual cell was filled with an image. Every 2 seconds the image diappears and fill another (or also the same) cell.

I have try in this way into my Activity class:

public void onCreate(Bundle savedInstanceState) {
      ....

        GridView grV = (GridView) findViewById(R.id.gridview);
        grV.setAdapter(myAd = new MyAdapter(this));
        
        startAnimation();
    }

private void startAnimation() {

GridView grV = (GridView) findViewById(R.id.gridview);
grV.getChildAt(count).setBackgroundResource(R.drawable.icon);
.....

startAnimation() //recursive!!!

}

but the method getChild does not return a cell (in my case, it returns null).

How can I perform the work?