前端工作总结116-实际案例解决vue+el-element二级联动，选项选择后不显示的问题

<el-form-item label="所属部门" :label-width="formLabelWidth">
            <select-form @change="DepartmentList"  v-model="form.department_id" />
          </el-form-item>
         <!-- <el-form-item prop="business_module" label="所属栏目" 
:label-width="formLabelWidth">
            <!&ndash;注意用户的返回值&ndash;>
            <el-select v-model="form.business_module"  
placeholder="请选择所属栏目" multiple>
              <el-option @click="resetLoginFrom" v-for="label in business_module" 
:label="label" :value="label"></el-option>
            </el-select>
          </el-form-item>-->
          <!--7column-->
          <el-form-item prop="column" label="所属单元" :label-width="formLabelWidth">
            <!--注意用户的返回值-->
            <el-select @change="updateFun" v-model="form.column"  
placeholder="请选择所属栏目" multiple>
              <el-option  v-for="column in columns" :label="column" 
:value="column"></el-option>
            </el-select>
          </el-form-item>

methods: {
    updateFun(){
      this.$forceUpdate();
    },
    /*封装网络请求 该数据为所属单元和所属项目*/
    DepartmentList(val) {
      /*取到val的数值*/
      this.form.column=''
        getAction("/department/attribute/"+val).then(res => {
          //回显数据
            /*this.business_module = res.data.business_module;*/
          console.log(res.data)
            this.columns = res.data.column;
      });
    },