Issue while loading Bitmap in AsyncTack

Issue

I am succesfully parsed xml and got text and url from tags and attributes. Text I was succesfully set into my ListView, but I cannot load my bitmap Into ImageView. I think I am forgetting something small, like some conversion somewhere or I have wrote wrong AsyncTask.

Here Is my parsing and AsyncTask call:

    private List<SomeItem> items = new ArrayList();

listView = findViewById(R.id.listView);
        IV = findViewById(R.id.iconsrc);

        ArrayList<String> list = new ArrayList<>();
        try {
            XmlPullParser parser = getResources().getXml(R.xml.myxml);

            while (parser.next() != XmlPullParser.END_DOCUMENT) {
                tagname = parser.getName();
                switch (parser.getEventType()){

                    case XmlPullParser.START_TAG:
                        if (tagname != null && tagname.equals(iconsrc)){
                            iconsrcVALUE = parser.getAttributeValue(0);
                            myBitmap = new AsyncForBitmap().execute(iconsrcVALUE).get();
                            IV.setImageBitmap(myBitmap);
                        }

                        break;

                    case XmlPullParser.TEXT :
                        tagtext = parser.getText();
                         break;

                    case XmlPullParser.END_TAG:

                        if (tagname != null && tagname.equals(displayname)) {

                            programmes.add(new SomeItem(tagtext, myBitmap));
                        }

                        break;
                }
            }

        } catch (Throwable t) {
            Toast.makeText(this,
                    "Error while loading xml document: " + t.toString(), Toast.LENGTH_LONG)
                    .show();
        }

        SomeAdapter adapter = new SomeAdapter(this, R.layout.list_item, items);
        listView.setAdapter(adapter);

My AsyncTask:

class AsyncForBitmap extends AsyncTask<String, Void, Bitmap> {
        private Exception exception;

        protected Bitmap doInBackground(String... urls) {
            try {
                URL url=new URL(urls[0]);
                Bitmap bitmap = BitmapFactory.decodeStream((InputStream)url.getContent());
                return bitmap;

            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }
}

Maybe I must add(overwrite) onPostExecute() method? But what I need to do there?

I tried smth like:

protected void onPostExecute(Bitmap bitmap) {
            IV.setImageBitmap(bitmap);
        }

But It Is wrong.

Solution

You can do something like passing of ImageView into AsyncTask in constructor. For this first modify your AsyncTask as below:

class AsyncForBitmap extends AsyncTask<String, Void, Bitmap> {

    private final ImageView mImageView;

    public AsyncForBitmap(ImageView imageView){
        mImageView = imageView;
    }

    private Exception exception;

    protected Bitmap doInBackground(String... urls) {
        try {
            URL url=new URL(urls[0]);
            Bitmap bitmap = BitmapFactory.decodeStream((InputStream)url.getContent());
            return bitmap;

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    protected void onPostExecute(Bitmap bitmap){
        mImageView.setImageBitmap(bitmap);
    }

}

And then, simply do as:

 ...
 case XmlPullParser.START_TAG:
     if (tagname != null && tagname.equals(iconsrc)){
        iconsrcVALUE = parser.getAttributeValue(0);
        new AsyncForBitmap(IV).execute(iconsrcVALUE);
     }
     break;

Answered By - Chintan Soni