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基于Vue3实现鼠标滑动和滚轮控制的轮播

作者：Jiude

在这篇文章主要为大家详细介绍了如何一步步地实现一个基于 Vue 3 的轮播组件,这个组件的特点是可以通过鼠标滑动和滚轮来控制轮播图的切换,感兴趣的可以了解下

需求

实现一个轮播组件，这个组件应该有以下的特性：

效果图

分析与设计

数组结构：

interface ListType {
    title: string
    icon: string
    img: string
    desc: string[]
}
const list: ListType = []

轮播中有一个唯一的active项，设置其下标为activeIndex

<ul class="swipper-wrapper">
    <li class="swipper-item" 
        v-for="(item, index) in list" 
        :class="{ active: index === activeIndex }"
        @click="activeIndex = index"
     >
      <img class="swipper-item-icon" :src="item.icon" alt="">
      {{ item.title }}
    </li>
 </ul>

const activeIndex = ref(0)

轮播最多可以同时展示7项，设置常量NUM默认值为7，理论上来说可以通过activeIndex获取展示的这7项的下标（即取距离activeIndex最近的7项, 因为需要距离最近，所以暂定这里NUM为奇数）：

const NUM = 7 // 展示的卡片数量（奇数）
function getSurroundingNumbers(length: number, activeIndex: number) {
  var start = activeIndex - (NUM - 1) / 2;
  var end = activeIndex + (NUM + 1) / 2;

  if (activeIndex < (NUM - 1) / 2) {
    start = 0;
    end = NUM;
  }

  if (activeIndex > length - (NUM + 1) / 2) {
    start = length - NUM;
    end = length;
  }

  var result = [];
  for (var i = start; i < end; i++) {
    result.push(i);
  }

  return result;
}

const surroundingNumbers = computed(() => getSurroundingNumbers(list.length, activeIndex.value))

比较每一项的下标和surroundingNumbers，知道他在数组的前面还是后面还是里面，从而设置相应的样式：

function getSwiperItemStyle(index: number) {
  // 每个卡片高度60px 间隔16px
  // 最多正常展示NUM个，其余藏在后，只露出16px高度
  const HIDEH = 15,
    H = 60,
    M = 16;
  
  let y = 0,
    scaleX = 1,
    backgroundColor = '#f9fbfc',
    zIndex = 9999,
    boxShadow = '2px 2px 1px 0px rgba(0,0,0,0.04), #fff 0px -2px 0px 0px';

  if (!surroundingNumbers.value.includes(index)) {
    backgroundColor = '#EBEDF2'
    zIndex = zIndex - Math.abs(activeIndex.value - index) + 2
    scaleX = 0.98 ** (Math.abs(activeIndex.value - index) + 2)

    if (index < surroundingNumbers.value[0]) {
      // 在上面
      y = HIDEH * index
      scaleX = 0.98 ** (surroundingNumbers.value[0] - index)
      boxShadow = '2px 2px 1px 0px rgba(255, 255, 255, .3) inset';
    } else {
      // 在下面
      y = surroundingNumbers.value[0] * HIDEH + (NUM - 1) * (H + M) + (index - surroundingNumbers.value.at(-1)!) * HIDEH
      scaleX = 0.98 ** (index - surroundingNumbers.value.at(-1)!)
      boxShadow = '2px 2px 1px 0px rgba(0,0,0,0.04)';
    }
  } else {
    y = surroundingNumbers.value[0] * HIDEH + (index - surroundingNumbers.value[0]) * (H + M)
  }

  if (activeIndex.value === index) {
    boxShadow = '5px 6px 12px 0px rgba(0,0,0,0.08), #fff 0px -2px 0px 0px';
  }


  return {
    transform: 'translateY(' + y / 19.2 + 'vw) scaleX(' + scaleX + ')',
    backgroundColor,
    zIndex,
    boxShadow
  }
}

<ul class="swipper-wrapper">
    <li class="swipper-item" 
        v-for="(item, index) in list" 
        :class="{ active: index === activeIndex }"
        :style="getSwiperItemStyle(index)"
        @click="activeIndex = index"
     >
      <img class="swipper-item-icon" :src="item.icon" alt="">
      {{ item.title }}
    </li>
 </ul>

交互实现

鼠标滚轮切换

绑定滚动事件@wheel="wheel"

// 处理鼠标滚动
function wheel(event: WheelEvent) {
  event.preventDefault(); // 防止页面滚动
  if (event.deltaY < 0) {
    // 向下滚动，activeIndex减少
    activeIndex.value = Math.max(0, activeIndex.value - 1);
  } else {
    // 向上滚动，activeIndex增加
    activeIndex.value = Math.min(list.length - 1, activeIndex.value + 1);
  }
}

鼠标滑动切换

绑定鼠标事件@mousedown="startSwipe" @mousemove="swipe" @mouseup="endSwipe" @mouseleave="endSwipe"

// 处理滑动
let startY = 0; // 鼠标按下时的y坐标
let accumulatedDiffY = 0; // 累积的滑动距离
let swiping = false; // 是否正在滑动

function startSwipe(event: MouseEvent) {
  startY = event.clientY;
  swiping = true;
}

function swipe(event: MouseEvent) {
  if (!swiping) return;
  const currentY = event.clientY;
  const diffY = currentY - startY;

  // 累积滑动距离
  accumulatedDiffY += diffY;

  // 假设每个元素的高度是100px
  const elementHeight = 84;

  // 使用累积的滑动距离计算滑动的元素数量，向下取整
  const numItems = Math.floor(Math.abs(accumulatedDiffY) / elementHeight);

  if (accumulatedDiffY > 0) {
    // 向下滑动，activeIndex减少
    if (activeIndex.value <= 2) return
    activeIndex.value = Math.min(list.length - 3, activeIndex.value)
    activeIndex.value = Math.max(0, activeIndex.value - numItems);
    accumulatedDiffY -= numItems * elementHeight; // 更新累积的滑动距离
  } else {
    // 向上滑动，activeIndex增加
    if (activeIndex.value >= list.length - 3) return
    activeIndex.value = Math.max(2, activeIndex.value)
    activeIndex.value = Math.min(list.length - 1, activeIndex.value + numItems);
    accumulatedDiffY += numItems * elementHeight; // 更新累积的滑动距离
  }

  // 更新起始Y坐标
  startY = currentY;
}

function endSwipe(event: MouseEvent) {
  swiping = false;
  accumulatedDiffY = 0; // 结束滑动时重置累积的滑动距离
}

自动切换

// 自动切换定时器
const { pause, resume } = useIntervalFn(() => {
  activeIndex.value++
  if (activeIndex.value >= list.length - 1) {
    activeIndex.value = 0
  }
}, 3000)

// 重新自动切换的倒计时
const { start: startTimeoutFn, stop: stopTimeoutFn } = useTimeoutFn(resume, 5000)

在每个用户操作的方法里先暂停自动切换pause()并停止继续切换的倒计时stopTimeoutFn，结束操作时再开启继续切换的倒计时startTimeoutFn。

完整代码

到此这篇关于基于Vue3实现鼠标滑动和滚轮控制的轮播的文章就介绍到这了,更多相关Vue3轮播内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！

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