Reputation: 446
I have this code to download a photo from a URL and display it in an ImageView on Android.
I am not sure how to loop this if I had a ArrayList or Array of multiple Urls to download and display on different ImageViews. I would appreciate any help or insight on how to proceed! Thank you!
public class DisplayPhotoTask extends AsyncTask<String, Void, Bitmap> {
@Override
protected Bitmap doInBackground(String... urls) {
Bitmap map = null;
for (String url : urls) {
map = downloadImage(url);
}
return map;
}
//sets bitmap returned by doInBackground
@Override
protected void onPostExecute(Bitmap result) {
ImageView imageView1 = (ImageView) findViewById(R.id.imageView);
imageView1.setImageBitmap(result);
}
//creates Bitmap from InputStream and returns it
private Bitmap downloadImage(String url) {
Bitmap bitmap = null;
InputStream stream = null;
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inSampleSize = 1;
try {
stream = getHttpConnection(url);
bitmap = BitmapFactory.decodeStream(stream, null, bmOptions);
stream.close();
} catch (IOException e1) {
e1.printStackTrace();
}
return bitmap;
}
//makes httpurlconnection and returns inputstream
private InputStream getHttpConnection(String urlString) throws IOException {
InputStream stream = null;
URL url = new URL(urlString);
URLConnection connection = url.openConnection();
try {
HttpURLConnection httpConnection = (HttpURLConnection) connection;
httpConnection.setRequestMethod("GET");
httpConnection.connect();
if (httpConnection.getResponseCode() == HttpURLConnection.HTTP_OK) {
stream = httpConnection.getInputStream();
}
} catch (Exception ex) {
ex.printStackTrace();
}
return stream;
}
}
Upvotes: 0
Views: 2856
Reputation: 2303
You can for example make a result of AsyncTask as List ant write something like this
protected Bitmap doInBackground(String... urls) {
List<Bitmap> bitmaps = new ArrayList<Bitmap>;
for (String url : urls) {
bitmaps.add(downloadImage(url));
}
return bitmaps;
}
protected void onPostExecute(List<Bitmap> result) {
//...
}
But what I really would recommend you is to use Volley library written by Google, it has really easy and powerful API (here is Google I/O session about it https://developers.google.com/live/shows/474338138 and repository https://android.googlesource.com/platform/frameworks/volley/)
Upvotes: 1