Vue 滑块验证组件实战：支持自定义图片与拖拽交互

Vue 滑块验证组件实战：支持自定义图片与拖拽交互

在实际项目中，我们经常遇到需要防刷或人机验证的场景。原生实现滑块验证码不仅繁琐，还要处理移动端兼容和边界限制。这里分享一个基于 Vue 的滑块验证组件方案，支持自定义背景图和滑块样式，同时兼顾了鼠标和触摸事件。

核心逻辑拆解

这个组件的核心在于子组件对拖拽行为的控制。我们需要监听 mousedown、mousemove 和 mouseup（以及对应的 touch 事件），计算偏移量并限制在容器范围内。此外，为了防止页面滚动穿透，还需要动态锁定 body 的滚动位置。

子组件实现

子组件负责渲染界面和处理交互。通过 data 属性接收配置，如宽高、图片路径等，并通过 $emit 向父组件反馈拖动状态。

<template>
  <div style="padding: 6px 7px">
    <!-- 背景图区域 -->
    <div class="box" :style="getStyle(1)">
      <img :style="getStyle(1)" :src="\`data:image/jpeg;base64,${data.image}\`" alt="">
      <!-- 缺口位置 -->
      <div class="slids" :style="{'left': elePos.x + 'px', 'top': elePos.y + 'px', ...getStyle(3) }">
        <img style="width: 100%; height: 100%" :src="\`data:image/jpeg;base64,${data.slide}\`" alt="">
      </div>
    </div>
    
    <!-- 滑块轨道 -->
    <div class="slidBox" :style="getStyle(2)">
      <div class="slidBoxItem"></div>
      <img class="slid" 
        :style="{width: '52px', height: '52px', margin: '1px 0 0 0','left': elePos.x + 'px', 'top': elePos.y + 'px' }" 
        src="@/assets/images/saleAndPurchase/handler_bg.png" alt=""
        @mousedown.self="dragStartHandler"
        @touchstart.stop="dragStartHandler"
        @mousemove="draggingHandler"
        @touchmove.stop="draggingHandler"
        @mouseup="dragEndHandler"
        @touchend.stop="dragEndHandler"
      >
    </div>
    
    <!-- 操作按钮 -->
    <div class="repossessColse">
      <img @click.stop="close" style="width: 24px; height: 24px; margin: 0 16px" src="@/assets/images/saleAndPurchase/closes.png" alt="">
      <img @click.stop="repossess" style="width: 24px; height: 24px" src="@/assets/images/saleAndPurchase/repossess.png" alt="">
    </div>
  </div>
</template>

<script>
/**
 * 必传参数 data
 * data={ width:number,height:number,randomStr:string,pos:{height:number},slideWidth:number,slideHeight:number,image:string}
 * ******************************
 * 回调方法 callBack(type,distance)
 * type: 按下滑块｜拖动滑块｜松开滑块
 * distance: 滑块已滑动的距离
 */
export default {
  props:['data'],
  components: {},
  data() {
    return {
      fatherbox: null,
      innerbox: null,
      slidsbox: null,
      // 元素位置，用于样式绑定，动态更新位置
      elePos: {
        x: null,
        y: null
      },
      // 手指（鼠标）触摸点距离拖拽元素左上角的距离
      diffOfTarget: {
        x: 0,
        y: 0
      }
    };
  },
  mounted() {
    this.$nextTick(() => {
      // 注意：实际项目中需确保这些选择器在当前 DOM 中可用
      this.fatherbox = document.querySelector('.van-popup');
      this.innerbox = document.querySelector('.slid');
      this.slidsbox = document.querySelector('.slids');
    });
  },
  methods: {
    getStyle(e){
      if(e == 1){
        return {
          width: this.data.width+'px',
          height: this.data.height+'px',
        }
      }else if(e == 2){
        return {
          width: this.data.width+'px',
        }
      }else if(e == 3){
        return {
          width: this.data.slideWidth+'px',
          height: this.data.slideHeight+'px',
          top: this.data.pos.height + 6 + 'px',
        }
      }
    },
    dragStartHandler (e) {
      let touch = e
      if (e.touches) {
        touch = e.touches[0]
      }
      // 记录初始偏移量
      this.diffOfTarget.x = touch.clientX - e.target.offsetLeft
      this.diffOfTarget.y = touch.clientY - e.target.offsetTop
      
      // 解决滑动穿透问题，固定 body 滚动位置
      let scrollTop = document.scrollingElement.scrollTop
      document.body.classList.add('modal-open')
      document.body.style.top = -scrollTop + 'px'
      
      let dragEndHandlerLeft = this.innerbox.offsetLeft-7
      this.$emit('callBack','dragStartHandler',dragEndHandlerLeft)
    },
    draggingHandler (e) {
      let touch = e
      if (e.touches) {
        touch = e.touches[0]
      }
      
      // 设置拖拽元素的位置
      this.elePos.x = touch.clientX - this.diffOfTarget.x

      // 限制元素不能超过滑道范围
      let limitWidth = this.fatherbox.offsetWidth - this.slidsbox.offsetWidth  - 7
      let limitHeight = window.screen.height
      
      if (this.elePos.x < 7) {
        this.elePos.x = 7
      } else if (this.elePos.x > limitWidth) {
        this.elePos.x = limitWidth
      }
      if (this.elePos.y < 0) {
        this.elePos.y = 0
      } else if (this.elePos.y > limitHeight) {
        this.elePos.y = limitHeight - e.target.clientHeight
      }

      let dragEndHandlerLeft = this.innerbox.offsetLeft-7
      this.$emit('callBack','draggingHandler',dragEndHandlerLeft)
    },
    dragEndHandler (e) {
      let dragEndHandlerLeft = this.innerbox.offsetLeft-7
      // 恢复 body 滚动
      document.body.classList.remove('modal-open')
      this.$emit('callBack','dragEndHandler',dragEndHandlerLeft)
    },
    repossess() { // 刷新重置
      this.elePos.x = null
      this.diffOfTarget.x = 0
      
      let scrollTop = document.scrollingElement.scrollTop
      document.body.classList.add('modal-open')
      document.body.style.top = -scrollTop + 'px'
      document.body.classList.remove('modal-open')
      this.$emit('repossess')
    },
    close() {
      this.$emit('close')
    }
  },
};
</script>

<style lang="scss" scoped>
.box {
  width: 350px;
  height: 100px;
  overflow: hidden;
}
.repossessColse {
  height: 40px;
  display: flex;
  justify-content: flex-end;
  flex-direction: row;
  align-items:flex-end;
}
.slidBox {
  width: 100%;
  height: 52px;
  overflow: none;
  margin: auto;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  .slidBoxItem {
    width: 98%;
    height: 37px;
    background-color: #E6E6E6;
    border-radius: 50px;
  }
  &::-webkit-scrollbar {
    width: 0px;
    height: 0px;
  }
  .slid {
    width: 52px;
    height: 52px;
  }
}
.slid {
  position: fixed;
  left: 7px;
  bottom: 46px;
  cursor: pointer;
}
.slids {
  position: fixed;
  left: 7px;
  top: 0px;
  width: 50px;
  height: 50px;
  cursor: pointer;
}
</style>