如何通过imageview投射视图将背景设置为imageView？

Question

I want to drop an image over an image and I have a code in which View is type casted by ImageView with v.name 'dropped' and this view will display on other ImageView named 'droptarget' as background but cant happend, plzz tell me a solution. my code is here.:

 case DragEvent.ACTION_DROP:

           //handle the dragged view being dropped over a target view

            View view = (View) event.getLocalState();

            //stop displaying the view where it was before it was dragged

            view.setVisibility(View.INVISIBLE);

            //view dragged item is being dropped on

            ImageView dropTarget = (ImageView) v;

            //view being dragged and dropped

            ImageView dropped = (ImageView) view;

            //it give me error in this line

            **dropTarget.setBackgroundResource(dropped);**

Answer 1

You should give us more info about the code but anyway I'm going to suggest something.

I think you're calling setBackgroundResource on a null object. So you're mistake is on the next line

ImageView dropTarget = (ImageView) v;

There probably isn't a view called "v". Maybe you should change that?

Answer 2

I believe you are looking for ImageView.setImageResource . You can also set the backgroundImage, but best practice is to use setimageResource.