vue实现下拉div

实现下拉展开/收起的Div组件

在Vue中实现下拉div效果可以通过动态控制CSS类和条件渲染实现。以下是两种常见实现方式：

基于CSS过渡的实现

<template>
  <div>
    <button @click="toggle">Toggle Dropdown</button>
    <div 
      class="dropdown-content"
      :class="{ 'active': isOpen }"
    >
      <p>下拉内容区域</p>
    </div>
  </div>
</template>

<script>
export default {
  data() {
    return {
      isOpen: false
    }
  },
  methods: {
    toggle() {
      this.isOpen = !this.isOpen
    }
  }
}
</script>

<style>
.dropdown-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out;
}

.dropdown-content.active {
  max-height: 500px; /* 调整为实际需要的高度 */
}
</style>

使用Vue过渡组件

<template>
  <div>
    <button @click="toggle">Toggle Dropdown</button>
    <transition name="slide">
      <div v-show="isOpen" class="dropdown-content">
        <p>过渡动画下拉内容</p>
      </div>
    </transition>
  </div>
</template>

<script>
export default {
  data() {
    return {
      isOpen: false
    }
  },
  methods: {
    toggle() {
      this.isOpen = !this.isOpen
    }
  }
}
</script>

<style>
.slide-enter-active, .slide-leave-active {
  transition: max-height 0.5s;
}
.slide-enter, .slide-leave-to {
  max-height: 0;
}
.slide-enter-to, .slide-leave {
  max-height: 500px;
}

.dropdown-content {
  overflow: hidden;
}
</style>

带点击外部关闭的功能

实现点击div外部区域关闭下拉效果：

<template>
  <div v-click-outside="close">
    <button @click="toggle">Toggle Dropdown</button>
    <div v-show="isOpen" class="dropdown-content">
      <p>点击外部关闭的内容</p>
    </div>
  </div>
</template>

<script>
export default {
  directives: {
    'click-outside': {
      bind(el, binding, vnode) {
        el.clickOutsideEvent = function(event) {
          if (!(el === event.target || el.contains(event.target))) {
            vnode.context[binding.expression](event)
          }
        }
        document.body.addEventListener('click', el.clickOutsideEvent)
      },
      unbind(el) {
        document.body.removeEventListener('click', el.clickOutsideEvent)
      }
    }
  },
  data() {
    return {
      isOpen: false
    }
  },
  methods: {
    toggle() {
      this.isOpen = !this.isOpen
    },
    close() {
      this.isOpen = false
    }
  }
}
</script>

可复用下拉组件封装

创建可复用的Dropdown组件：

<!-- Dropdown.vue -->
<template>
  <div class="dropdown" v-click-outside="close">
    <div class="dropdown-trigger" @click="toggle">
      <slot name="trigger"></slot>
    </div>
    <transition name="fade">
      <div v-show="isOpen" class="dropdown-menu">
        <slot name="content"></slot>
      </div>
    </transition>
  </div>
</template>

<script>
export default {
  props: {
    closeOnClickOutside: {
      type: Boolean,
      default: true
    }
  },
  data() {
    return {
      isOpen: false
    }
  },
  methods: {
    toggle() {
      this.isOpen = !this.isOpen
    },
    close() {
      if (this.closeOnClickOutside) {
        this.isOpen = false
      }
    }
  }
}
</script>

<style>
.dropdown {
  position: relative;
  display: inline-block;
}

.dropdown-menu {
  position: absolute;
  background: white;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  z-index: 1000;
}

.fade-enter-active, .fade-leave-active {
  transition: opacity 0.2s;
}
.fade-enter, .fade-leave-to {
  opacity: 0;
}
</style>

使用示例：

<template>
  <Dropdown>
    <template v-slot:trigger>
      <button>点击展开</button>
    </template>
    <template v-slot:content>
      <p>自定义下拉内容</p>
      <button>选项1</button>
    </template>
  </Dropdown>
</template>