bitmap設置背景顏色

    public static Bitmap drawBitmapBg(int color, Bitmap bt) {
        Paint paint = new Paint();
        paint.setColor(color);
        Bitmap bitmap = Bitmap.createBitmap(orginBitmap.getWidth(),
                orginBitmap.getHeight(), orginBitmap.getConfig());
        Canvas canvas = new Canvas(bt);
        canvas.drawRect(0, 0, orginBitmap.getWidth(), orginBitmap.getHeight(), paint);
        canvas.drawBitmap(orginBitmap, 0, 0, paint);
        return bitmap;

    }

如果canvas不設置paint,則背景顏色微透明。