表单enter键代替tab键切换（依赖iview组件库）

需求：通过使用键盘enter键，实现tab键对表单元素的切换。通过给每个控件添加class="test"获取需要切换的控件，虽实现功能需求，但仍有很大的优化空间。

1. 封装keydown.js文件

export function getKeyDown(className){
   //当前页面监视键盘输入
   document.onkeydown = function(e) {
       if(e.keyCode === 13){
           // 阻止文本框的换行
           if(window.event){
               window.event.returnValue = false;
           }else{
               e.preventDefault(); //for firefox
           }
           // 标记当前组件为true
           if(e.target.tagName === 'INPUT'){
               e.target.autofocus = true;
           }else if(e.target.tagName === 'TEXTAREA'){
               e.target.autofocus = true;
           }else{
               e.target.firstChild.autofocus = true;
           }
           // 获取所有需要定位的组件
           let arr = document.querySelectorAll("."+className);
           let index2 = -1;
           arr.forEach((i,index) => {
               if(i.querySelectorAll("input")[0]){
                   if(i.querySelectorAll("input")[0].autofocus){
                       index2 = index;
                   }
               }else if(i.querySelectorAll("textarea")[0]){
                   if(i.querySelectorAll("textarea")[0].autofocus){
                       index2 = index;
                   }
               }else{
                   // 暂无其他
               }
           })
           // 超出返回第一个组件
           if(index2 + 1 >= arr.length){
               index2 = -1;
           }
           // 聚焦到下一个组件中
           if(arr[index2 + 1].querySelectorAll("input")[0]){
               if(arr[index2 + 1].querySelectorAll("input")[0].type === 'hidden'){
                   arr[index2 + 1].querySelectorAll("input")[0].parentElement.focus();
               }else{
                   arr[index2 + 1].querySelectorAll("input")[0].focus();
               }
           }else if(arr[index2 + 1].querySelectorAll("textarea")[0]){
               arr[index2 + 1].querySelectorAll("textarea")[0].focus();
           }else{
               // 暂无其他
           }
           // 重置当前组件为false
           if(e.target.tagName === 'INPUT'){
               e.target.autofocus = false;
           }else if(e.target.tagName === 'TEXTAREA'){
               e.target.autofocus = false;
           }else{
               e.target.firstChild.autofocus = false;
           }    
       }
   }
}

2. 组件中引用

<template>
    <Form ref="formValidate" :model="formValidate" :rules="ruleValidate" :label-width="80">
        <FormItem label="Name" prop="name">
            <Input class="test" v-model="formValidate.name" placeholder="Enter your name"></Input>
        </FormItem>
        <FormItem label="E-mail" prop="mail">
            <Input class="test" v-model="formValidate.mail" placeholder="Enter your e-mail"></Input>
        </FormItem>
        <FormItem label="City" prop="city">
            <Select class="test" v-model="formValidate.city" placeholder="Select your city">
                <Option value="beijing">New York</Option>
                <Option value="shanghai">London</Option>
                <Option value="shenzhen">Sydney</Option>
            </Select>
        </FormItem>
        <FormItem label="Date">
            <Row>
                <Col span="11">
                    <FormItem prop="date">
                        <DatePicker class="test" type="date" placeholder="Select date" v-model="formValidate.date"></DatePicker>
                    </FormItem>
                </Col>
                <Col span="2" style="text-align: center">-</Col>
                <Col span="11">
                    <FormItem prop="time">
                        <TimePicker class="test" type="time" placeholder="Select time" v-model="formValidate.time"></TimePicker>
                    </FormItem>
                </Col>
            </Row>
        </FormItem>
        <FormItem label="Hobby" prop="interest">
            <CheckboxGroup v-model="formValidate.interest">
                <Checkbox class="test" label="Eat"></Checkbox>
                <Checkbox class="test" label="Sleep"></Checkbox>
                <Checkbox class="test" label="Run"></Checkbox>
                <Checkbox class="test" label="Movie"></Checkbox>
            </CheckboxGroup>
        </FormItem>
        <FormItem label="Gender" prop="gender">
            <RadioGroup v-model="formValidate.gender">
                <Radio class="test" label="male">Male</Radio>
                <Radio class="test" label="female">Female</Radio>
            </RadioGroup>
        </FormItem>
        <FormItem label="Switch">
            <i-switch class="test" v-model="formValidate.switch" size="large">
                <span slot="open">On</span>
                <span slot="close">Off</span>
            </i-switch>
        </FormItem>
        <FormItem label="Desc" prop="desc">
            <Input class="test" v-model="formValidate.desc" type="textarea" :autosize="{minRows: 2,maxRows: 5}" placeholder="Enter something..."></Input>
        </FormItem>
        <FormItem>
            <Button type="primary" @click="handleSubmit('formValidate')">Submit</Button>
            <Button @click="handleReset('formValidate')" style="margin-left: 8px">Reset</Button>
        </FormItem>
    </Form>
</template>
<script>
    import { getKeyDown } from '@/libs/keydown'
    export default {
        data () {
            return {
                formValidate: {
                    name: '',
                    mail: '',
                    city: '',
                    gender: '',
                    interest: [],
                    date: '',
                    time: '',
                    switch: true,
                    desc: ''
                },
                ruleValidate: {
                    name: [
                        { required: true, message: 'The name cannot be empty', trigger: 'blur' }
                    ],
                    mail: [
                        { required: true, message: 'Mailbox cannot be empty', trigger: 'blur' },
                        { type: 'email', message: 'Incorrect email format', trigger: 'blur' }
                    ],
                    city: [
                        { required: true, message: 'Please select the city', trigger: 'change' }
                    ],
                    gender: [
                        { required: true, message: 'Please select gender', trigger: 'change' }
                    ],
                    interest: [
                        { required: true, type: 'array', min: 1, message: 'Choose at least one hobby', trigger: 'change' },
                        { type: 'array', max: 2, message: 'Choose two hobbies at best', trigger: 'change' }
                    ],
                    date: [
                        { required: true, type: 'date', message: 'Please select the date', trigger: 'change' }
                    ],
                    time: [
                        { required: true, type: 'string', message: 'Please select time', trigger: 'change' }
                    ],
                    desc: [
                        { required: true, message: 'Please enter a personal introduction', trigger: 'blur' },
                        { type: 'string', min: 20, message: 'Introduce no less than 20 words', trigger: 'blur' }
                    ]
                }
            }
        },
        methods: {
            handleSubmit (name) {
                this.$refs[name].validate((valid) => {
                    if (valid) {
                        this.$Message.success('Success!');
                    } else {
                        this.$Message.error('Fail!');
                    }
                })
            },
            handleReset (name) {
                this.$refs[name].resetFields();
            }
        },
        created() {
            let that = this
            getKeyDown('test');
        }
    }
</script>