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javaandroidandroid-bitmap

"Canvas: trying to draw too large bitmap" problem in Android Studio


When I try to get bitmap from website, Canvas: trying to draw too large problem is occured.

So I search this problem on google and many people wrote their solutions, but that solution is about bitmap file in directory drawable.

  • What should I do if the bitmap image taken from the website is too large?

This is my code.

            Thread mThread = new Thread() {
                @Override
                public void run() {
                    try {
                        URL url = new URL(postImgUrl);

                        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                        conn.setDoInput(true);
                        conn.connect();

                        InputStream inputStream = conn.getInputStream();
                        postImgBitmap = BitmapFactory.decodeStream(inputStream);
                        inputStream.close();
                        conn.disconnect();

                    } catch (MalformedURLException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            };
            mThread.start();
            mThread.join();

            if (postImgBitmap != null){
                postImg.setImageBitmap(postImgBitmap);

When a problem occurs, variable postImgUrl is "http://www.hstree.org/data/ck_tmp/202001/de3kOOtFqV6Bc2o7xCa7vg1UwFWJ.jpg" and variable postImg is ImageView.

Please advise me.


Solution

  • The error means the size of Bitmap is too large for the ImageView. Before setImageBitmap() to ImageView, you can scale the large Bitmap to a smaller one with Bitmap.createScaledBitmap(). Then you can safely set the Bitmap to ImageView.

    A sample code:

    public class MainActivity extends AppCompatActivity {
        private static final String imageUrl
            = "http://www.hstree.org/data/ck_tmp/202001/de3kOOtFqV6Bc2o7xCa7vg1UwFWJ.jpg";
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            final ImageView imageView = findViewById(R.id.imageView);
    
            new Thread(new Runnable() {
                @Override
                public void run() {
                    URL url = null;
                    try {
                        url = new URL(imageUrl);
                    } catch (MalformedURLException e) {
                        e.printStackTrace();
                    }
    
                    try (BufferedInputStream bufferedInputStream
                            = new BufferedInputStream(url.openStream())) {
                        Bitmap bitmap = BitmapFactory.decodeStream(bufferedInputStream);
    
                        final Bitmap scaledBitmap = Bitmap.createScaledBitmap(
                            bitmap,
                            (int) (bitmap.getWidth() * 0.1),
                            (int) (bitmap.getHeight() * 0.1),
                            true
                        );
    
                        runOnUiThread(new Runnable() {
                            @Override
                            public void run() {
                                imageView.setImageBitmap(scaledBitmap);
                            }
                        });
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }).start();
        }
    }