element-ui级联选择器为多选（multiple:true,emitPath:false,checkStrictly:false）
核心在于值改变后，检查全选子集，push对应上级菜单
选中

5824CFA3-3FEA-4c99-9FD8-A1F6207C54BC.png

返回

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<div class="block">
  <el-cascader
    :options="options"
    :props="props"
    @change="cascaderChange"
    v-model="cascaderData"
    clearable></el-cascader>
</div>

<script>
  export default {
    data() {
      return {
        cascaderData:[],
        props: { multiple:true,emitPath:false,checkStrictly:false },
        options: [{
          value: '1',
          label: '东南',
          children: [{
            value: '2',
            label: '上海',
            children: [
              { value: '3', label: '普陀' },
              { value: '4', label: '黄埔' },
              { value: '5', label: '徐汇' }
            ]
          }, {
            value: '7',
            label: '江苏',
            children: [
              { value: '8', label: '南京' },
              { value: '9', label: '苏州' },
              { value: '10', label: '无锡' }
            ]
          }, {
            value: '12',
            label: '浙江',
            children: [
              { value: '13', label: '杭州' },
              { value: '14', label: '宁波' },
              { value: '15', label: '嘉兴' }
            ]
          }]
        }, {
          value: '17',
          label: '西北',
          children: [{
            value: '18',
            label: '陕西',
            children: [
              { value: '19', label: '西安' },
              { value: '20', label: '延安' }
            ]
          }, {
            value: '21',
            label: '新疆维吾尔自治区',
            children: [
              { value: '22', label: '乌鲁木齐' },
              { value: '23', label: '克拉玛依' }
            ]
          }]
        }]
      };
    },
    methods: {
      cascaderChange(val){
        if (val && val.length > 0) {
        //赋值
        let ob = {};
        //recursive处理ob数据源
        //参数1：ob 接收处理后的数据
        //参数2：this.options el-cascader 选择数据源
        //参数3：'value'  值键名
        //参数4：'children' 子集键名
        //参数5：null
        //参数6：null
        this.recursive(ob,this.options,'value','children',null,null)
        //检测赋值
        if(ob&&JSON.stringify(ob)!="{}"){
          for (const key in ob) {
            let len = 0
            for(let j = 0 ; j < val.length ; j++){
              if(ob[key].includes(val[j])){
                len ++
              }
            }
            if(ob[key].length===len){
              this.cascaderData.push(key)
            }
          }
        }
        }
      },
    // element Cascader 级联选择器 数据处理
    recursive(object,data,valueKey,subsetKey,last,lastData){
      if(last){
        object[last] = [];
      }
      if(data&&data.length>0){
        for(let i = 0 ; i < data.length ; i++){
          if(last&&!data[i][subsetKey]){
            object[last].push(data[i][valueKey])
          }
          if(lastData&&!data[i][subsetKey]){
            lastData.push(data[i][valueKey])
          }
          if(data[i][subsetKey]&&data[i][subsetKey].length>0){
            this.recursive(object,data[i][subsetKey],valueKey,subsetKey,data[i][valueKey],object[last])
          }
        }
      }
    },
    }
  };
</script>