Component({ data: { top: "550px", left: "345px", viewHeight: null }, lifetimes: { attached: function () { let that = this; wx.getSystemInfo({ success: (res => that.setData({ viewHeight: res.windowHeight })) }); }, }, methods: { viewTouchMove(e) { let left = e.touches[0].pageX; if (left > 375) left = 375; if (left < 0) left = 0; let top = e.touches[0].pageY; if (top < 0) top = 0; if (top > this.data.viewHeight) top = this.data.viewHeight; this.setData({ left: left + 'px', top: top + 'px' }) } } })