Recycle ImageView's Bitmap

Question

I have something like this:

Bitmap.Config conf = Bitmap.Config.ARGB_8888;
WeakReference<Bitmap> bm = new WeakReference<Bitmap>(Bitmap.createBitmap(3000 + 3000, 2000, conf));

Canvas canvas = new Canvas(bm.get());
canvas.drawBitmap(firstBitmap, 0, 0, null);
canvas.drawBitmap(bm, firstBitmap.getWidth(), 0, null);

imageView.setImageBitmap(bm);

And I apply this on more than 10 imageView's which are created one by one. Whenever I create new ImageView, I want to recycle the 'bm' object from the first one, cause this code up there, causes my heap to grow more and more and then throw OutOfMemoryError, so I do:

bm.recycle()

right after I set the Bitmap (bm) to the imageView object. This causes exception that the ImageView's canvas wants to draw recycled Bitmap.

What is the way to recycle a Bitmap that has already been put as image on ImageView?

Thanksb

Answer 1

In your onDestroy method you could try something like this:

ImageView imageView = (ImageView)findViewById(R.id.my_image);
Drawable drawable = imageView.getDrawable();
if (drawable instanceof BitmapDrawable) {
    BitmapDrawable bitmapDrawable = (BitmapDrawable) drawable;
    Bitmap bitmap = bitmapDrawable.getBitmap();
    bitmap.recycle();
}

The cast should work since setImageBitmap is implemented as

public void setImageBitmap(Bitmap bm) {
    setImageDrawable(new BitmapDrawable(mContext.getResources(), bm));
}