可任意拖动的客服按钮

html：

 <button style="bottom:{{ballBottom}}px;right:{{ballRight}}px;" bindtouchmove="ballMoveEvent">  
 </button>

JS:

Page({
	    data: {
	        ballBottom: 240,
	        ballRight: 120,
	        screenHeight: 0,
	        screenWidth: 0,  
	   },
	   onl oad: function (option) {
	         var that = this;
	        wx.getSystemInfo({
	            success: function (res) {
	                that.setData({
	                    screenHeight: res.windowHeight,
	                    screenWidth: res.windowWidth,
	                });
	            }
	        });
	    },
	    ballMoveEvent: function (e) {
		        // console.log('我被拖动了....')
		        var touchs = e.touches[0];
		        var pageX = touchs.pageX;
		        var pageY = touchs.pageY;
		        //防止坐标越界,view宽高的一般
		        if (pageX < 30) return;
		        if (pageX > this.data.screenWidth - 30) return;
		        if (this.data.screenHeight - pageY <= 30) return;
		        if (pageY <= 30) return;
		        //这里用right和bottom.所以需要将pageX pageY转换
		        var x = this.data.screenWidth - pageX - 30;
		        var y = this.data.screenHeight - pageY - 30;
		        // console.log('x: ' + x)
		        // console.log('y: ' + y)
		        this.setData({
			            ballBottom: y,
			            ballRight: x
		        });
	    }
})

标签：function,拖动,res,pageY,可任意,pageX,按钮,var,screenWidth
来源： https://blog.csdn.net/qq_43218075/article/details/96562352