下拉选择框监听el-option的方式

 <el-select v-model="form.expenseType" placeholder="请选择费用类型" clearable filterable size="small">
            <el-option v-for="item in expenseNameList" :key="item.value" :label="item.label" :value="item.label"
              @click.native="expenseChange(item)" />
</el-select>