android:display image in listview

Question

I am trying to display an image in listview from url using JSON parsing. the image url displays correctly in log. when i am trying to download image and display in list getting NullPointerException in bmImage.setImageBitmap(result); i am using following code can anyone tell me the solution..

 private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
     ImageView bmImage;

    public DownloadImageTask(ImageView bmImage) {
        this.bmImage = bmImage;
    }

    protected Bitmap doInBackground(String... urls) {

        Bitmap bt_img = null;


        try {
             FileInputStream in = new FileInputStream(urls[0]);

             InputStream in = new java.net.URL(urls[0]).openStream();
             bt_img = BitmapFactory.decodeStream(in);
        } catch (Exception e) {
             Log.e("Error", e.getMessage());
             e.printStackTrace();
        }
        return bt_img;
    } 

    protected void onPostExecute(Bitmap result) {
        try {
            bmImage.setImageBitmap(result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Use Android Query for this dear, its very very efficient and working very fine — Pratik Dasa, Aug 19 '14 at 09:23
Visit here: here is my answer with my name there: http://stackoverflow.com/questions/541966/how-do-i-do-a-lazy-load-of-images-in-listview/17917897#17917897, check it and do like that way, it will work fine I am damn sure — Pratik Dasa, Aug 19 '14 at 09:23
try using Universal Image Loader library for asynchronously loading images.All you have to do is pass the URL of the image and the imageview and you will get your desired results — williamj949, Aug 19 '14 at 10:11

score 0 · Answer 1 · answered Aug 19 '14 at 09:26

0

If you are getting a nullPointerException on the bmImage variable, it means it has not been initialized. As in the code you provide you are not getting its reference, you have to be passing it to the AsyncTask.

What is the code where you pass the bmImage reference, invoking your AsyncTask? The problem seems to be in that code, not in the AsyncTask itself.

answered Aug 19 '14 at 09:26

Adrián Moreno Peña

356
1
5
9

i am calling this AsyncTask in my code as new DownloadImageTask(image).execute(image_); here image is nothing but image = ((ImageView)findViewById(R.id.image_list)); and image_ is my image url. – Namitha Aug 19 '14 at 09:32
@Namitha I think this is totally bad idea, there should be many possibilities to crashing the app, why should you doing hardcoded, because we have libraries to use directly. – Pratik Dasa Aug 19 '14 at 09:34
@pratik can you tell me which libraries i should use – Namitha Aug 19 '14 at 09:40
I have commented you above just check it dear, there are many like AQuery, Picasso, but AQuery is mindblowing. – Pratik Dasa Aug 19 '14 at 09:42
@namitha have you got it or not? – Pratik Dasa Aug 19 '14 at 09:58
no i am getting to create class for AQuery.. i need to add any jar file? – Namitha Aug 19 '14 at 10:07
@namitha yes, you have to add jar file named AQuery.jar , download link is there. You can download from there. Should I send you working example? – Pratik Dasa Aug 19 '14 at 10:14
give me your email id, let me send you aQuery.jar file first – Pratik Dasa Aug 19 '14 at 10:22
hmmm, now just use it, and that's it, just one line of code and you are done – Pratik Dasa Aug 19 '14 at 10:46

Priyank Prajapati · Answer 2 · 2014-08-19T10:01:30.560

0

 1)  best way is use Lazy Loding 
    and
 2) second way is try this code,
    try {
            URL imageURL = new URL(imgUrl);
            qrBitmap = BitmapFactory.decodeStream(imageURL.openStream());

            image.setImageBitmap(qrBitmap);

            } catch (Exception e) {
            Log.d("QRDisplay", e.getMessage());
            }

edited Aug 19 '14 at 10:01

answered Aug 19 '14 at 09:46

Priyank Prajapati

183
10

score -1 · Answer 3 · answered Aug 19 '14 at 20:10

-1

You have to use the Universal Image Loader for getting the images from the server.

this link help to u

https://github.com/nostra13/Android-Universal-Image-Loader

answered Aug 19 '14 at 20:10

sachin bhanot

19
3

android:display image in listview

3 Answers3