Viewpager Webview memory issue

Question

I\'m using a viewpager to load around 50 webviews... All the webviews are loaded into assests and each weview has an HTML page that is accessing around 70 images each... As

Answer 1

Try to scale down bitmap.Most of the time Bitmap is a main reason we get Memory issue. Also learn about how to recycle the bitmaps. Following snippet will help you.

BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeFile( filename, options );
        options.inJustDecodeBounds = false;
        options.inSampleSize = 2; 

        bitmap = BitmapFactory.decodeFile( filename, options );
        if ( bitmap != null && exact ) {
            bitmap = Bitmap.createScaledBitmap( bitmap, width, height, false );
        }

Also make sure you did override following method.

@Override
public void destroyItem(View collection, int position, Object view) {
    ((ViewPager) collection).removeView((TextView) view);
}

Or you can create a function to Scale Down Bitmap

private byte[] resizeImage( byte[] input ) {

    if ( input == null ) {
        return null;
    }

    Bitmap bitmapOrg = BitmapFactory.decodeByteArray(input, 0, input.length);

    if ( bitmapOrg == null ) {
        return null;
    }

    int height = bitmapOrg.getHeight();
    int width = bitmapOrg.getWidth();
    int newHeight = 250;

    float scaleHeight = ((float) newHeight) / height;

    // creates matrix for the manipulation
    Matrix matrix = new Matrix();
    // resize the bit map
    matrix.postScale(scaleHeight, scaleHeight);

    // recreate the new Bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
            width, height, matrix, true);

    bitmapOrg.recycle();

    ByteArrayOutputStream bos = new ByteArrayOutputStream();
    resizedBitmap.compress(CompressFormat.PNG, 0 /*ignored for PNG*/, bos);            

    resizedBitmap.recycle();

    return bos.toByteArray();            
}       

Answer 2

Setting layer type of webview to software works.

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
    webView.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}

But now you lose hardware acceleration and your webview may slow down.

Answer 3

The WebView works with the JNI and this can only hold 512 local references, try loading your content directly from web and the problem shouldn't occur.

I get this problem when I override shouldInterceptRequest(WebView view, String url) in webviewclient and hand local references from my own caching mechanism.

This might be a bug in the webview itself. At least it isn't how it should behave if you ask me.