页面上有个fixed悬浮按钮，希望可以在页面上任意拖动位置，但是现在的问题是写出来的拖动效果特别不流畅（反应延迟），请问有什么好的办法解决？ <view class='helpbox' style="bottom:{{bottom}}px;right:{{right}}px;" catchtouchmove='setTouchMove'> <image class='helpimg' src='/images/help.png'></image> </view> js代码： setTouchMove:function(e){     var that = this;     var width = 35 * rpx;     var screenWidth = wx.getSystemInfoSync().windowWidth;     var screenHeight = wx.getSystemInfoSync().windowHeight;     var clientX = e.touches[0].clientX;     var clientY = e.touches[0].clientY;     //此处clientY与clientX为拖动悬浮窗超过设定的大小会返回默认显示位置     if (clientX < (screenWidth - width) && clientY < (screenHeight - width) && clientX > width && clientY > width) {         that.setData({             right: screenWidth - clientX - width,             bottom: screenHeight - clientY - width         })     } else {         return;         // that.setData({         //   right: 0, //默认显示位置 left距离         //   bottom: 0  //默认显示位置 top距离         // })     } }