Android：单击每个按钮即可创建新的ImageView

Question

I want to generate and add a new ImageView by a button click everytime the button is pressed. This is my code:

entwicklungskarte.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            ImageView iv = new ImageView(getApplicationContext());
            iv.setImageResource(R.drawable.erfindungek);
            ResourcenActivity.entwicklungskarten.add(iv);
        }
    });

But when I click on the button twice, I get this error:

java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first.

I thought that it would create a new ImageView by every button click. But it obviously doesn't. Is there any other way to create and add an ImageView to the layout by button click?

Answer 1

Declare a field previousId in you class private int previousId=0; You will have to set an incremental id of your image view iv

 iv.setId(++previousId);

before

ResourcenActivity.entwicklungskarten.add(iv);

So that every time the corresponding parent is asked to add a new child with different ID than the previous one.

Answer 2

if(view != null) {
    return view; 
}