效果图

代码块

  <div>
      <span v-for="(item,index) in showHandleList" :key="item.index">
         <span>{{item.emailFrom}}</span>
      </span>
      <span v-if="this.list.length > 4" @click="showAll = !showAll">{{word}}</span>
  </div>

	data(){
		return{
		    list:[{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        },{
	          emailFrom:'利晴天<liqingtian@163.com>'
	        }],
	        
	        showAll:false
		}
	},
	computed:{    
	  showHandleList(){      
	    if(this.showAll == false){  //收起状态-显示“展示”        
	      var showList = [];  //定义⼀个空数组        
	      if(this.list.length > 4){  //控制显⽰前四个          
	        for(var i = 0;i < 4; i++){            
	          showList.push(this.list[i])  //将数组的前4条存放到showList数组中        
	        }        
	      }else{          
	        showList = this.list;  //个数足够显示，不需要再截取        
	      }        
	      return showList;  //返回当前数组      
	    }else{  // 展开状态-显示“收起”      
	      return this.list;      
	    }    
	  },    
	  word(){      
	    if(this.showAll == false){  //对⽂字进⾏处理        
	      return '展开'      
	    }else{       
	      return '收起'      
	    }    
	  }  
	},