iView的Select选择框动态取值

 <Form v-show="show_step2" :model="editPosition" style="padding:10px 0;">
        <Row>
            <FormItem label="职位：">
                <Select v-model="editPosition.positionName" @on-change="changeSelect">
                    <Option
                        v-for="(positionType) in positionTypes"
                        :key="positionType.id"
                        :value="positionType.name"
                    >{{positionType.name}}</Option>
                </Select>
            </FormItem>
        </Row>
</Form>   

方法：

changeSelect(positionName: string) {
    this.editPosition.positionName = positionName;
 }