<div class="page-bar">
 <ul>
 <li v-if="showFirstText"><a v-on：click="cur--">上一页</a></li>

 <li v-for = "index in pagenums">
 <a v-on:click="pageChange(index)">{{index}}</a>

 </li>

 <li v-if="showNextText"><a v-on：click="cur++">下一页</a></li>
 <li><a>共<i>{{all}}</i>页</a></li>
 </ul>

</div>

var app = new Vue({
 el: '#app',
 data:{
 currentpage: 1,
 totlepage: 28,
 visiblepage:10,
 msg: ''
 },
})

computed: {
 //计算属性：返回页码数组，这里会自动进行脏检查，不用$watch();
 pagenums: function(){
 //初始化前后页边界
 var lowPage = 1;
 var highPage = this.totlepage;
 var pageArr = [];
 if(this.totlepage > this.visiblepage){//总页数超过可见页数时，进一步处理；
 var subVisiblePage = Math.ceil(this.visiblepage/2);
 if(this.currentpage > subVisiblePage && this.currentpage < this.totlepage - subVisiblePage +1){//处理正常的分页
 lowPage = this.currentpage - subVisiblePage;
 highPage = this.currentpage + subVisiblePage -1;
 }else if(this.currentpage <= subVisiblePage){//处理前几页的逻辑
 lowPage = 1;
 highPage = this.visiblepage;
 }else{//处理后几页的逻辑
 lowPage = this.totlepage - this.visiblepage + 1;
 highPage = this.totlepage; 
 }
 }
 //确定了上下page边界后，要准备压入数组中了
 while(lowPage <= highPage){
 pageArr.push(lowPage);
 lowPage ++;
 }

 return pageArr;
 }
 },

<li v-for="index in pagenums" v-bind:class="{ active: currentpage == index}">
 <a v-on:click="pageChange(index)">{{ index }}</a>
 </li>

methods:{
 pageChange: function(page){
 if (this.currentpage != page) {
 this.currentpage = page;
 this.$dispatch('page-change', page); //父子组件间的通信：==>子组件通过$diapatch(),分发事件，父组件冒泡通过v-on:page-change监听到相应的事件；
 };
 }
 }

watch: {
 currentpage: function(oldValue , newValue){
 console.log(arguments)
 }
}