<router-view v-slot="{ Component }">
      <transition :name="transitionName" mode="out-in">
        <component :is="Component" />
      </transition>
    </router-view>

 data() {
    return {
      // schema: "MainFade",
      transitionName: "slide-left",
    };
  },

watch: {
    //使用watch 监听$router的变化
    $route(to, from) {
      //如果to索引大于from索引,判断为前进状态,反之则为后退状态
      if (to.meta.index > from.meta.index) {
        //设置动画名称
        this.transitionName = "slide-left";
      } else {
        this.transitionName = "slide-right";
      }
    },
  },

//css样式 
.slide-right-enter-active,
.slide-right-leave-active,
.slide-left-enter-active,
.slide-left-leave-active {
  will-change: transform;
  transition: all 500ms;
  position: absolute;
}
.slide-right-enter {
  opacity: 0;
  transform: translate3d(-100%, 0, 0);
}
.slide-right-leave-active {
  opacity: 0;
  transform: translate3d(100%, 0, 0);
}
.slide-left-enter {
  opacity: 0;
  transform: translate3d(100%, 0, 0);
}
.slide-left-leave-active {
  opacity: 0;
  transform: translate3d(-100%, 0, 0);
}

<template>
  <div>
    <router-view v-slot="{ Component }">
      <transition :name="transitionName" mode="out-in">
        <component :is="Component" />
      </transition>
    </router-view>
  </div>
</template>
<script>
export default {
  name: "AppTestApp",
  data() {
    return {
      // schema: "MainFade",
      transitionName: "slide-left",
    };
  },
  mounted() {},
  methods: {},
  watch: {
    //使用watch 监听$router的变化
    $route(to, from) {
      //如果to索引大于from索引,判断为前进状态,反之则为后退状态
      console.log(to, "to");
      console.log(from, "from");
      if (to.meta.index > from.meta.index) {
        //设置动画名称
        this.transitionName = "slide-left";
      } else {
        this.transitionName = "slide-right";
      }
    },
  },
};
</script>
<style>
.slide-right-enter-active,
.slide-right-leave-active,
.slide-left-enter-active,
.slide-left-leave-active {
  will-change: transform;
  transition: all 500ms;
  position: absolute;
}
.slide-right-enter {
  opacity: 0;
  transform: translate3d(-100%, 0, 0);
}
.slide-right-leave-active {
  opacity: 0;
  transform: translate3d(100%, 0, 0);
}
.slide-left-enter {
  opacity: 0;
  transform: translate3d(100%, 0, 0);
}
.slide-left-leave-active {
  opacity: 0;
  transform: translate3d(-100%, 0, 0);
}
</style>