element Cascader 选中任意一级，点击文字选中且选

<el-form-item label="组织者" prop="organizer">
                  <el-cascader
                    ref="organizerUnit"
                    v-model="temp.organizer"
                    :options="joinPeopleList"
                    :disabled="isShow.isDisabled"
                    :props="{ checkStrictly: true , value: 'id', label: 'name',}"
                    placeholder="请选择组织者"
                    :show-all-levels="false"
                    expand-trigger="hover"
                    class="w100_pidR30"
                    @change="organizerUnit"
                  />
  </el-form-item>


  organizerUnit(a) {
      if (this.$refs.organizerUnit) {
        this.$refs.organizerUnit.dropDownVisible = false
      }
    },