把一張圖縮小放到另一張背景圖上。

   /**
     *  bitmap 圖片縮放到指定大小
     */
    public static Bitmap resizeImage(Bitmap bitmap, int w, int h)
    {
        Bitmap BitmapOrg = bitmap;
        int width = BitmapOrg.getWidth();
        int height = BitmapOrg.getHeight();
        int newWidth = w;
        int newHeight = h;
        
        float scaleWidth = ((float)newWidth) / width;
        float scaleHeight = ((float)newHeight) / height;
        
        Matrix matrix = new Matrix();
        matrix.postScale(scaleWidth, scaleHeight);
        // if you want to rotate the Bitmap
        // matrix.postRotate(45);
        Bitmap resizedBitmap = Bitmap.createBitmap(BitmapOrg, 0, 0, width, height, matrix, true);
        return resizedBitmap;
    }

   /**
     * 把一張圖放到另一張背景圖上。
     */

public static Drawable addbackground4onlyicon(Bitmap b1, Bitmap b2,Context mContext)
    {
        if (!b1.isMutable())
        {
            // 設置圖片為背景為透明
            b1 = b1.copy(Bitmap.Config.ARGB_8888, true);
        }
        Paint paint = new Paint();
        Canvas canvas = new Canvas(b1);
        
        
        
        canvas.drawBitmap(b2, 17.5f, 17.5f, paint);// 疊加新圖b2 (120-85)/2= 17.5
        canvas.save(Canvas.ALL_SAVE_FLAG);
        canvas.restore();
        return  new BitmapDrawable(mContext.getResources(), b1);
    }