小程序bindtouchend在向左滑动时移出屏幕外不触发，但向右向上向下都可以触发
wxml

<view id="id" class = "ball" bindtouchstart = "handletouchtart" bindtouchmove="handletouchmove" bindtouchend="handletouchend" style = "width : 100%px; height : 40px;">
{{text}}
</view>

wxss

.ball {
  box-shadow:2px 2px 10px #AAA;
  border-radius: 20px;
  position: absolute; 
  left: 50%;
  top: 50%;
 }

js

Page({
 data: {
  lastX: 0,     //滑动开始x轴位置
  lastY: 0,     //滑动开始y轴位置
  text: "没有滑动",
  currentGesture: 0, //标识手势
 },
 //滑动移动事件
 handletouchmove: function (event) {
  var currentX = event.touches[0].pageX
  var currentY = event.touches[0].pageY
  var tx = currentX - this.data.lastX
  var ty = currentY - this.data.lastY
  var text = ""
  //左右方向滑动
  if (Math.abs(tx) > Math.abs(ty)) {
   if (tx < 0)
    text = "向左滑动"
   else if (tx > 0)
    text = "向右滑动"
  }
  //上下方向滑动
  else {
   if (ty < 0)
    text = "向上滑动"
   else if (ty > 0)
    text = "向下滑动"
  }
 
  //将当前坐标进行保存以进行下一次计算
  this.data.lastX = currentX
  this.data.lastY = currentY
  this.setData({
   text: text,
  });
 },
 
 //滑动开始事件
 handletouchtart: function (event) {
  //console.log(this.data.lastX)
  this.data.lastX = event.touches[0].pageX
  this.data.lastY = event.touches[0].pageY
 },
 //滑动结束事件
 handletouchend: function (event) {
  console.log(event)
  this.data.currentGesture = 0;
  this.setData({
   text: "没有滑动",
  });
 },
})