How to convert a Drawable to a Bitmap?

Question

I would like to set a certain Drawable as the device\'s wallpaper, but all wallpaper functions accept Bitmaps only. I cannot use WallpaperMan

Answer 1

Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.icon);

This will not work every time for example if your drawable is layer list drawable then it gives a null response, so as an alternative you need to draw your drawable into canvas then save as bitmap, please refer below a cup of code.

public void drawableToBitMap(Context context, int drawable, int widthPixels, int heightPixels) {
    try {
        File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/", "drawable.png");
        FileOutputStream fOut = new FileOutputStream(file);
        Drawable drw = ResourcesCompat.getDrawable(context.getResources(), drawable, null);
        if (drw != null) {
            convertToBitmap(drw, widthPixels, heightPixels).compress(Bitmap.CompressFormat.PNG, 100, fOut);
        }
        fOut.flush();
        fOut.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

private Bitmap convertToBitmap(Drawable drawable, int widthPixels, int heightPixels) {
    Bitmap bitmap = Bitmap.createBitmap(widthPixels, heightPixels, Bitmap.Config.ARGB_8888);
    Canvas canvas = new Canvas(bitmap);
    drawable.setBounds(0, 0, widthPixels, heightPixels);
    drawable.draw(canvas);
    return bitmap;
}

above code save you're drawable as drawable.png in the download directory