How to set image from drawables using AsyncTask in Android Studio

Issue

I am trying to perform a very simple task (loading image to ImageView in the background), but can't make it to work. Any help much appreciated.

Here is what I have so far: This is how I call the class in on create in the main thread:

 LoadImage  newImage=new LoadImage();
 newImage.execute(myImgeView);

Next I created the class:

public class LoadImage extends AsyncTask<ImageView, Void, ImageView> {

ImageView imageView;


        @Override
        protected ImageView doInBackground(ImageView... params) {
            Log.e("myTag",": Can it see this class from where I call it? Yes it does" );
     
            imageView.setImageResource(R.drawable.myNewImage);
       

            return imageView;
        }

    }

I can't figure out how to set it up correctly. It crashes saying something like: Attempt to invoke virtual method 'void android.widget.ImageView.setImageResource(int)' on a null object reference.

Thanks in advance for your help.

Solution

The problem lies in this code:

imageView.setImageResource(R.drawable.myNewImage);

The variable imageView can't be seen from the AsyncTask Class, the imageView you want is inside the params array so you can reference it with params[0]. So replace the above code with:

ImageView imageView = params[0];
imageView.setImageResource(R.drawable.myNewImage);
return imageView;

Answered By - Kidus