vue 功能：点击增加一项，点击减少一项

功能介绍：

默认为一列，当点击右侧"+" 号，增加一列；点击 “-” 号，将当前列删除；

功能截图：

功能代码：

//HTML
<el-col :span="24">
	<el-form-item label="通道列表：" prop="mobile">
		<div class="passStreamList">
			<div class="container" v-for="(item,key) in formDialog.form.passStreamList">
				<el-input v-model="item.code" type="text" class="dialogFormInputStyle dmzcode" clearable placeholder="编号,只能为数字类型"></el-input> 
				<div class="span"> - </div> 
				<el-input v-model="item.name" type="text" class="dialogFormInputStyle dmzname" clearable placeholder="请输入通道名称"></el-input> 
				<div class="span"> - </div> 
				<el-select v-model="item.type" class="dialogFormInputStyle dmztype" style="width:20%">
					<el-option v-for="item1 in formDialog.dmzType" :key="item1.id" :label="item1.type" :value="item1.id" placeholder="站类型">
						<span style="float: left;font-size: 12px">{{item1.type}}</span>
					</el-option>
				</el-select>
				<div class="dmzbutton">
					<span class="add" @click="passStreamAdd">+</span>
					<span class="reduce" @click="passStreamReduce(key)">-</span>
				</div>
			</div>
		</div>
	</el-form-item>
</el-col>

//css
 .passStreamList{
	 width:100%;
	 .container{
		 width:100%;
		 display:flex;
		 flex-direction: row;
		 justify-content: space-between;
		 .dmzcode,.dmzname{
			width:28%;
			cursor: pointer;
		 }
		 div.span{
			 color:#fff;
		 }
		 .dmztype{
			width:20%;
			cursor: pointer;
		 }
		 .dmzbutton{
			 display:flex;
			 justify-content: space-around;
			 align-items: center;
			 span{
				 width:25px;
				 height:25px;
				 font-size:20px;
				 background:rgba(155,226,254,0.5);
				 border: 1px solid #9BE2FE;
				 cursor: pointer;
				 color:#fff;
				 text-align:center;
				 line-height:25px;
			 }
			 span:last-child{
				 margin-left:10px;
			 }
		 }
	 }
 }

data(){
	return {
		formDialog:{
			form:{
				passStreamList:[{}],
			}
		}
	}
},

//增加
passStreamAdd(){
	this.formDialog.form.passStreamList.push({})
},

//减少
passStreamReduce(index){
	let newArr = [];
	//为一层时禁止减
	if(this.formDialog.form.passStreamList.length == 1){ return; }
	if(index == 0){   
		//为首
		newArr = this.formDialog.form.passStreamList.slice( 1,this.formDialog.form.passStreamList.length)
	}else if(index == this.formDialog.form.passStreamList.length-1){  
		//为尾
		newArr = this.formDialog.form.passStreamList.slice( 0,this.formDialog.form.passStreamList.length-1)
	}else{  
		//为中
		let arr1 = this.formDialog.form.passStreamList.slice( 0,index)
		let arr2 = this.formDialog.form.passStreamList.slice( index+1, this.formDialog.form.passStreamList.length)
		newArr = arr1.concat(arr2)
	}
	this.formDialog.form.passStreamList = [].concat(newArr);
},