【VUE】用vue写一个轮播图组件（二）

接上篇

• 先总结下上篇技巧：
• 提供一个v-model进行父子组件间数据交换。
• 使用vue内置动画实现移动的动画效果。
• 另外用watch监控value的变动来显示子组件变化。
• 这次要实现的功能：
• 完成可以正序播放和逆序播放功能。
• 完成鼠标移入停止，移出继续轮播功能。
• 加入轮播图小点功能，点击小点可以切换轮播页面。
• 建立index.html支持手机端大小。
• 加入轮播图左右按钮，可左右切换轮播。

代码

App.vue

<template>
  <swiper v-model="selected" autoplay>
    <swiperItem name="box1">
      <div class="content" style="background:red">页面1div>
    swiperItem>
    <swiperItem name="box2">
      <div class="content" style="background:green">页面2div>
    swiperItem>
    <swiperItem name="box3">
      <div class="content" style="background:yellow">页面3div>
    swiperItem>
  swiper>
template>
<script>
import swiperItem from "./components/SwiperItem";
import swiper from "./components/Swiper";
export default {
  data: () => {
    return { selected: "box3" };
  },
  components: {
    swiper,
    swiperItem
  }
};
script>
<style lang="stylus">
.content {
  width: 100%;
  height: 300px;
  text-align: center;
  margin: auto;
}
style>

Swiper.vue

<template>
  

    <div class="viewport">
      <slot>slot>
      <div class="dot">
        <span
          v-for="(item,index) in len "
          :key="index"
          :class="{active:active===index}"
          @click="select(index)"
        >{{item}}span>
      div>
      <div class="sidebutton">
        <div @click="leftclick">左div>
        <div @click="rightclick">右div>
      div>
    div>
  div>
template>

<script>
export default {
  props: {
    value: {
      type: String,
      default: ""
    },
    autoplay: {
      type: Boolean,
      default: true
    }
  },
  methods: {
    touchmove(e){
      console.log('移动');
      console.log(e);
    },
    touchstart(e){
      this.startx = e.touches[0].clientX
      clearInterval(this.timer)
    },
    touchend(e){
      let endx = e.changedTouches[0].clientX
      let distance = endx-this.startx
      let trifNum = 20
      if(distance>trifNum){
        this.select(this.active-1)
      }else if(distance < -trifNum){
        this.select(this.active+1)
      }
      this.autoShow()
    },
    leftclick() {
      let newIndex = this.active - 1;
      this.select(newIndex);
    },
    rightclick() {
      let newIndex = this.active + 1;
      this.select(newIndex);
    },
    select(newIndex) {
      this.prev = this.active;
      if (newIndex === this.names.length) newIndex = 0;
      if (newIndex === -1) newIndex = this.names.length - 1;
      this.$emit("input", this.names[newIndex]);
    },
    showChild() {
      this.currentName = this.value || this.$children[0].name;
      this.$children.forEach(vm => {
        this.$nextTick(() => {
          vm.selected = this.currentName;
        });
        let updateIndex = this.active;
        let reverse = updateIndex > this.prev ? false : true;
        if (this.prev === 0 && updateIndex === this.len - 1) reverse = true;
        if (this.prev === this.len - 1 && updateIndex === 0) reverse = false;
        vm.reverse = reverse;
      });
    },
    autoShow() {
      if (this.autoplay) {
        this.timer = setInterval(() => {
          let index = this.active;
          let newIndex;
          let isreverse = false;
          if (isreverse) {
            newIndex = index - 1;
          } else {
            newIndex = index + 1;
          }
          this.select(newIndex);
        }, 2000);
      }
    },
    mouseEnter() {
      clearInterval(this.timer);
      this.timer = null;
    },
    mouseLeave() {
      if (!this.timer) {
        this.autoShow();
      }
    }
  },
  computed: {
    active() {
      return this.names.indexOf(this.currentName);
    }
  },
  watch: {
    value() {
      this.showChild();
    }
  },
  beforeDestroy() {
    clearInterval(this.timer);
  },
  data() {
    return { currentName: "", len: 0 };
  },
  mounted() {
    this.names = this.$children.map(vm => vm.name);
    this.len = this.names.length;
    this.showChild();
    this.autoShow();
    this.prev = this.active;
  }
};
script>
<style lang="stylus">
.swiper {
  border: 5px solid black;
  height: 300px;
  margin: auto;
  text-align: center;
}

.viewport {
  position: relative;
  overflow: hidden;
  width: 100%;
  height: 100%;
}

.dot {
  display: flex;
  justify-content: center;
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;

  span {
    height: 30px;
    width: 30px;
    border-radius: 100%;
    background-color: white;
    text-align: center;
    line-height: 30px;
    border: 1px solid black;
    margin: 0 10px 0;
    cursor: pointer;

    &.active {
      background-color: red;
    }
  }
}

.sidebutton {
  display: flex;
  justify-content: space-between;
  position: absolute;
  width: 100%;
  height: w = 30px;
  top: 50%;
  transform: translateY(-50%);
  text-align: center;
  line-height: w;
  font-size: 15px;

  div {
    background-color: purple;
    padding: 1px;

    &:nth-child(1) {
      border-top-left-radius: 80%;
      border-bottom-left-radius: 80%;
    }

    &:nth-child(2) {
      border-top-right-radius: 80%;
      border-bottom-right-radius: 80%;
    }
  }
}
style>

SwiperItem.vue

<template>
  <transition>
    <div class="swiper-item" v-if="isShow" :class="{reverse}">
      <slot>slot>
    div>
  transition>
template>

<script>
export default {
  props: {
    name: {
      type: String,
      required: true
    }
  },
  data() {
    return { selected: "", reverse: "" };
  },
  mounted() {},
  computed: {
    isShow() {
      return this.name === this.selected;
    }
  }
};
script>
<style lang="stylus">
.v-enter-active, .v-leave-active {
  transition: all 0.5s linear;
}

.v-leave-to {
  transform: translate(-100%);
}

.v-enter {
  transform: translate(100%);
}

.v-leave-to.reverse {
  transform: translate(100%);
}

.v-enter.reverse {
  transform: translate(-100%);
}

.v-leave-active {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
}
style>

• html就是直接感叹号出来的就不发了。使用vue serve 默认挂到id为app的节点。
• 总的来说还有不少缺点，样式不够美观，功能没完全放给用户，再学习一段时间后准备重弄个更好的试试。