[]点击区域问题

发现精灵的点击区域不对，要怎么弄呢，下面是代码

        var space = Browser.clientWidth / 12;
        var btnWidth = (Browser.clientWidth - space * 5) / 4;
        var btnHeight = btnWidth;
        btn_bottom.size(btnWidth, btnHeight);
        scaleX = btnWidth / btn_imgWidth;
        scaleY = btnHeight / btn_imgHeight;
        var scaleMin = scaleX > scaleY ? scaleY : scaleX;
        btn_bottom[i].pos(btnWidth * i + space * (i + 1), Browser.clientHeight - btnHeight - 10);
        btn_bottom[i].scale(scaleMin, scaleMin);
        var rect = new Laya.Rectangle(btnWidth * i + space * (i + 1), Browser.clientHeight - btnHeight - 10, btnWidth, btnHeight);
        console.log("rect"+i+":"+rect);
//        btn_bottom[i].hitArea = rect; 
        btn_bottom[i].on("click", this, bottomClick, [i]);[/i][/i][/i][/i][/i]
不加hitArea时，点击区域在左上方一小块，加了后完全无效