Android上bitmap和drawable之间互转简介

Drawable drawable = new BitmapDrawable(mActivity.getResources(),bitmap);

public static Bitmap getBitmapFromDrawable(Drawable drawable) {
    Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), drawable
            .getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
            : Bitmap.Config.RGB_565);
    Canvas canvas = new Canvas(bitmap);
    drawable.draw(canvas);
    return bitmap;
}

Bitmap bitmap = ((BitmapDrawable) mActivity.getDrawable(R.drawable.item_selected_bg)).getBitmap();