vue-router 手势滑动触发返回功能

vue-router的路由变换只存在“变换前”和“变换后”，不存在“切换中”的状态，所以做不到大多数app（微信那样的）在滑动过程中让界面跟随手指移动。但滑动事件还是可以监听的，我们可以在滑动之后再触发路由回退事件。

微博的滑动返回基本上就是这样的原理：先滑动、再触发返回事件，但用起来很是怪异，有严重的滞后感。夸克浏览器做的就比较好：一是滑动时界面虽然不动，但是界面上有小图标提示，能让用户接受到反馈；二是返回过程很快，没有多余的过渡动画。

app.vue文件如下：

<template>
 <div id="app" v-on:touchstart="bodyTouchStart" v-on:touchmove="bodyTouchMove" v-on:touchend="bodyTouchEnd">
 <transition :name="direction">
  <keep-alive include="home">
  <router-view class="appView"></router-view>
  </keep-alive>
 </transition>
 </div>
</template>

<script>
var swidth = document.documentElement.clientWidth;

export default {
 name: 'app',
 data: () => ({
 // direction 页面切换的过渡动画，配合transition组件使用
 direction: "slide-left",
 // touchLeft 划动起点界限，起点在靠近屏幕左侧时才有效
 touchLeft: swidth*2/5,
 // touchStartPoint 记录起始点X坐标
 touchStartPoint: 0,
 // distance 记录划动的距离
 distance: 0,
 // 回退按钮的dom，根据页面上是否存在此dom来判断该路由是否可回退
 backBtn: null
 }),

 watch: {
 // 监听路有变化，决定页面过渡动画
 $route(to, from) {
  if (from.name == "login" || from.path.indexOf("home") > -1) {
  this.direction = "slide-left";
  } else if (to.path.indexOf("home") > -1) {
  this.direction = "slide-right";
  } else {
  const toDepth = to.path.split("/").length;
  const fromDepth = from.path.split("/").length;
  this.direction = toDepth < fromDepth ? "slide-right" : "slide-left";
  }
 }
 },

 methods: {
 bodyTouchStart: function(event) {
  this.backBtn = document.getElementById("navback");
  if (this.backBtn) {
  // 获得起点X坐标，初始化distance为0
  this.touchStartPoint = event.targetTouches[0].pageX;
  this.distance = 0;
  }
 },
 bodyTouchMove: function(event) {
  if (this.backBtn && this.touchStartPoint < this.touchLeft) {
  // 只监听单指划动，多指划动不作响应
  if (event.targetTouches.length > 1) {
   return;
  }
  // 实时计算distance
  this.distance = event.targetTouches[0].pageX - this.touchStartPoint;
  // 根据distance在页面上做出反馈。这里演示通过返回按钮的背景变化作出反馈
  if (this.distance > 0 && this.distance < 100) {
   this.backBtn.style.backgroundPosition = ((this.distance - 100) / 100) * 50 + "px 0";
  } else if (this.distance >= 100) {
   this.backBtn.style.backgroundPosition = "0 0";
  } else {
   this.backBtn.style.backgroundPosition = "-50px 0";
  }
  }
 },
 bodyTouchEnd: function(event) {
  if (this.backBtn && this.touchStartPoint < this.touchLeft) {
  // 划动结束，重置数据
  this.touchStartPoint = 0;
  this.backBtn.style.backgroundPosition = "-50px 0";
  // 当划动距离超过100px时，触发返回事件
  if (this.distance > 100) {
   // 返回前修改样式，让过渡动画看起来更快
   document.getElementById("app").classList.add("quickback");
   this.$router.back();
   setTimeout(function(){
   document.getElementById("app").classList.remove("quickback");
   },250)
  }
  }
 }
 }
}
</script>

<style>
#app {
 -webkit-font-smoothing: antialiased;
 -moz-osx-font-smoothing: grayscale;
 width: 100%;
 overflow-x: hidden;
}
.appView {
 position: absolute;
 width: 100%;
 background: #fff;
 min-height: 100vh;
 transition: transform 0.24s ease-out;
}
#app.quickback .appView{
 transition-duration: 0.1s;
}
.slide-left-enter {
 transform: translate(100%, 0);
}
.slide-left-leave-active {
 transform: translate(-50%, 0);
}
.slide-right-enter {
 transform: translate(-50%, 0);
}
.slide-right-leave-active {
 transform: translate(100%, 0);
}
</style>

下面看下vue图片左右滑动及手势缩放

引入vue-awesome-swiperimport 'swiper/dist/css/swiper.css';

import { swiper, swiperSlide } from 'vue-awesome-swiper';components: {
 swiper,
 swiperSlide,
},data() {
 return {
 swiperOption: {
  width: window.innerWidth,
  zoom : true,
  initialSlide: 0,
 },
 };
},<swiper :options="swiperOption" ref="imgOverview" style="height: 100%;">
 <swiper-slide v-for="(img, index) in previewImg">
 <div class="swiper-zoom-container">
  <img :src="img" alt="">
 </div>
 </swiper-slide>
</swiper>

代码案例见 https://github.com/yource/VueSPA

总结