不多说直接上代码：

<template>
	<div class="ip-box">
		<el-input v-model.number="ip1" name="ip" maxlength="3" onkeyup="value=value.replace(/[^\d]/g,'')" @keyup.native="keyupEvent(1,$event)" @blur="submitIp" @input="(val) => checkVal(val,'ip1')" ref="ip1"></el-input>
		<div class="ip-dot"></div>
		<el-input v-model.number="ip2" name="ip" maxlength="3" onkeyup="value=value.replace(/[^\d]/g,'')" @keyup.native="keyupEvent(2,$event)" @blur="submitIp" @input="(val) => checkVal(val,'ip2')" ref="ip2"></el-input>
		<div class="ip-dot"></div>
		<el-input v-model.number="ip3" name="ip" maxlength="3" onkeyup="value=value.replace(/[^\d]/g,'')" @keyup.native="keyupEvent(3,$event)" @blur="submitIp" @input="(val) => checkVal(val,'ip3')" ref="ip3"></el-input>
		<div class="ip-dot"></div>
		<el-input v-model.number="ip4" name="ip" maxlength="3" onkeyup="value=value.replace(/[^\d]/g,'')" @keyup.native="keyupEvent(4,$event)" @blur="submitIp" @input="(val) => checkVal(val,'ip4')" ref="ip4"></el-input>
		<i class="el-icon-circle-close" @click="clearValue"></i>
	</div>
<script>
export default {
	name: 'ipInput',
	data () {
		return {
			ip1: null,
			ip2: null,
			ip3: null,
			ip4: null
		}
	},
	props: ['defaultIp'],   //耦合那种填写ip提交后再次打开网页可以看到之前填写的值（需要后端配合）
	created () {
		if(this.defaultIp) {
			let ipList = this.defaultIp.split('.');
			this.ip1 = ipList[0];
			this.ip2 = ipList[1];
			this.ip3 = ipList[2];
			this.ip4 = ipList[3];
		}
	},
	computed: {
		isRightVal () {
		//判断填入的四个ip值是否为数字，只有有一个为非数字则为true
			let reg = /[^\d]/g;
			return reg.test(this.ip1) || reg.test(this.ip2) || reg.test(this.ip3) || reg.test(this.ip4);
		}	
	},
	methods: {
		clearValue () {
			//重置ip输入框
			this.ip1 = null;
			this.ip2 = null;
			this.ip3 = null;
			this.ip4 = null;
			this.$emit('getIpVal',''); //清除输入框传空值
		},
		submitIp () {
			//失去焦点判断值是否输入完整，并向父组件传整个ip值
			if(this.ip1 && this.ip2 !=null && this.ip3 !=null && this.ip4 !=null) {
				if (this.isRightVal) {
				//这里也可以加个提示框之类的提示用户
					this.clearValue();
				}else {
					let ipVal = this.ip1 + '.' + this.ip2 + '.' + this.ip3 + '.' + this.ip4;
				this.$emit('getIpVal',ipVal);
				this.$parent.$emit("el.form.change"); //这是防止elementui的form表单验证必填项时显示文字的也就是required,用不到可不写	
				}
				
			}else {
				return;
			}
		},
		checkVal (val,key) {
		//判断输入的ip值
			if(parseInt(val) > 255) {
			//输入值超过255，则显示为255，并且跳到下一个输入框
				switch(key) {
					case "ip1":
						this.ip1 = 255;
						this.focusInput(2);
						break;
					case "ip2":
						this.ip2 = 255;
						this.focusInput(3);
						break;
					case "ip3":
						this.ip3 = 255;
						this.focusInput(4);
						break;
					case "ip4":
						this.ip4 = 255;
						break;
					default: 
						break;
				}
			}else if(parseInt(val) <= 255 && parseInt(val) >= 100){
				//输入三位数自动跳到下一个输入值
				switch(key) {
					case "ip1":
						this.focusInput(2);
						break;
					case "ip2":
						this.focusInput(3);
						break;
					case "ip3":
						this.focusInput(4);
						break;
					default: 
						break;
				}
			}
		},
		focusInput (index) {
		//控制输入框的聚焦
			switch(key) {
					case "ip2":
						this.$refs.ip2.focus();
						break;
					case "ip3":
						this.$refs.ip3.focus();
						break;
					case "ip4":
						this.$refs.ip4.focus();
						break;
					default: 
						break;
				}
		},
		keyupEvent (index,e) {
		//按下.键跳到下一个输入框（同理可做出其他按键的跳转输入框）
			if(e.keyCode === 110) {
			//这里尝试过用this.focusInput发现没有效果（具体原因暂未知....）
				if(index == 1) {
					this.$refs.ip2.focus();
				}else if(index == 2){
					this.$refs.ip3.focus();
				}else{
					this.$refs.ip4.focus();
				}
			}
		}
	}
}
</script>
<style lang='less' scoped>
.ip-box {
	width: 240px;
	border:1px solid #576372;
	height: 32px;
	display: flex;
	align-items: cneter;
	position: relative;
	/deep/ .el-input__inner {
		border: 0 !important;
	}
	/deep/ .el-input {
		width: 60px;
	}
	.el-icon-circle-close {
		color: #fff;
		display: none;
		font-size: 12px;
		cursor: pointer;
		position: absolute;
		right: 2px;
	}
	&:hover {
		.el-icon-circle-close{
			display: inline-block;
		}
	}
}
.ip-dot {
	display: inline-block;
	width: 3px;
	height: 3px;
	border-radius: 50%;
	background-color: #fff;
}
</style>
</template>