Null pointer Exception - findViewById()

Question

Can anyone help me to find out what can be the issue with this program. In the onCreate() method the findViewById() returns null for all ids and th

Answer 1

The views you're trying to get are not defined in your activity_main layout. You need to programmatically inflate the views you're trying to add to the pager.-

@Override
public Object instantiateItem(ViewGroup collection, int position) {
    LinearLayout l = null;

    if (position == 0) {
        l = (LinearLayout) View.inflate(this, R.layout.activity_first, null);
    }
    if (position == 1) {
        l = (LinearLayout) View.inflate(this, R.layout.activity_second, null);
    }
    if (position == 2) {
        l = (LinearLayout) View.inflate(this, R.layout.activity_third, null);
    }

    collection.addView(l, position);
    return l;
}