vue+element select树形下拉

组件页面代码（新增multiple 多选模式默认 false）

<template>
  <el-select
    :title="multiple? optionData.name : ''"
    ref="select"
    :value="value"
    placeholder="请选择"
    size="mini"
    clearable
    :disabled="disabled"
    :filterable="filterable"
    :filter-method="filterMethod"
    style="width: 100%;"
    @clear="clear"
    @visible-change="visibleChange"
  >
    <el-option
      ref="option"
      class="tree-select__option"
      :value="optionData.id"
      :label="optionData.name"
    >
      <el-tree
        ref="tree"
        class="tree-select__tree"
        :class="`tree-select__tree--${multiple ? 'checked' : 'radio'}`"
        :node-key="nodeKey"
        :data="data"
        :props="props"
        :default-expanded-keys="[value]"
        :show-checkbox="multiple"
        :highlight-current="!multiple"
        :expand-on-click-node="multiple"
        :filter-node-method="filterNode"
        @node-click="handleNodeClick"
        @check-change="handleCheckChange"
      ></el-tree>
    </el-option>
  </el-select>
</template>

<script>
export default {
  name: 'TreeSelect',
  props: {
    // v-model绑定
    value: {
      type: [String, Number],
      default: ''
    },
    multiple: {
      type: Boolean,
      default: true //单项 false   多选true
    },
    // 树形的数据
    data: {
      type: Array,
      default: function () {
        return []
      }
    },
    // 每个树节点用来作为唯一标识的属性
    nodeKey: {
      type: [String, Number],
      default: 'id'
    },
    filterable: {
      type: Boolean,
      default: false
    },
    disabled: {
      type: Boolean,
      default: false
    },
    // tree的props配置
    props: {
      type: Object,
      default: function () {
        return {
          label: 'label',
          children: 'children'
        }
      }
    }
  },
  data() {
    return {
      optionData: {
        id: '',
        name: ''
      },
      filterFlag: false
    }
  },
  watch: {
    value: {
      handler(val) {
        if (!this.isEmpty(this.data)) {
          this.init(val)
        }
      },
      immediate: true
    },
    data: function (val) {
      if (!this.isEmpty(val)) {
        this.init(this.value)
      }
    }
  },
  created() {},
  methods: {
    // 是否为空
    isEmpty(val) {
      for (let key in val) {
        return false
      }
      return true
    },
    handleNodeClick(data) {
      if (this.multiple) {
        return
      }
      this.$emit('input', data[this.nodeKey])
      this.$refs.select.visible = false
    },
    handleCheckChange() {
      const nodes = this.$refs.tree.getCheckedNodes()
      const value = nodes.map((item) => item[this.nodeKey]).join(',')
      this.$emit('input', value)
    },
    init(val) {
      // 多选
      if (this.multiple) {
        const arr = val.toString().split(',')
        this.$nextTick(() => {
          this.$refs.tree.setCheckedKeys(arr)
          const nodes = this.$refs.tree.getCheckedNodes()
          this.optionData.id = val
          this.optionData.name = nodes
            .map((item) => item[this.props.label])
            .join(',')
        })
      }
      // 单选
      else {
        val = val === '' ? null : val
          this.$nextTick(() => {
            this.$refs.tree.setCurrentKey(val)
            if (val === null) {
              return
            }
            const label = this.props.label || 'name'
            const node = this.$refs.tree.getNode(val)
            this.optionData.id = val
            this.optionData[label] = node.label
          })
      }
    },
    visibleChange(e) {
      if (e) {
        const tree = this.$refs.tree
        this.filterFlag && tree.filter('')
        this.filterFlag = false
        let selectDom = null
        if(this.multiple) {
          selectDom = tree.$el.querySelector('.el-tree-node.is-checked')
        } else {
          selectDom = tree.$el.querySelector('.is-current')
        }
        setTimeout(() => {
          this.$refs.select.scrollToOption({ $el: selectDom })
        }, 0)
      }
    },
    clear() {
      this.$emit('input', '')
    },
    filterMethod(val) {
      this.filterFlag = true
      this.$refs.tree.filter(val)
    },
    filterNode(value, data) {
      if (!value) return true
      const label = this.props.label || 'name'
      return data[label].indexOf(value) !== -1
    }
  }
}
</script>

<style lang="scss">
.tree-select__option {
  &.el-select-dropdown__item {
    height: auto;
    line-height: 1;
    padding: 0;
    background-color: #fff;
  }
}

.tree-select__tree {
  padding: 4px 20px;
  font-weight: 400;
  &.tree-select__tree--radio {
    .el-tree-node.is-current > .el-tree-node__content {
      color: $mainColor;
      font-weight: 700;
    }
  }
}
</style>

vue 页面引用

<template>
    <div class="container">
        <cy-tree-select v-model="value" filterable :data="list" ref="tselect"></cy-tree-select>
    </div>
</template>

<script>
	import cyTreeSelect from '../components/treeSelect/index'
export default {
    data() {
        return {
            list: [{
                label: '系统',
                id: 1,
                children: [
                    { label: '用户', id: 2 },
                    { label: '用户组', id: 3 },
                    { label: '角色', id: 4 },
                    { label: '菜单', id: 5 },
                    { label: '组织架构', id: 6 }
                ]
            },
            {
                label: '商品',
                id: 7,
                children: [
                    { label: '列表', id: 8 },
                    { label: '添加', id: 9 },
                    { label: '修改', id: 10 },
                    { label: '删除', id: 11 },
                    { label: '商品分类', id: 12 },
                    { label: '分类修改', id: 13 }
                ]
            }],
            value: 1 //多选时获取的是label，单选时获取的是id
        }
    }
}
//let s = this.$refs.tselect.optionData
	//			console.log(s) //数据拿取 optionData: {id: '',name: ''}格式
</script>

转载于https://zhuanlan.zhihu.com/p/415995268，供学习