小程序分页及行号公式

//数据初始化
data: {
		page_now: 0,//当前页
		totalCount: 0,//数据总数
		pageSize: 15,//每页显示条数
		Person_info: []//记录内容
},
//获取记录总数
getdata() {
 var that = this;
		db.collection('Person_DB').count({
			success: function (res) {				
				var yeshu = Math.ceil(res.total / that.data.pageSize)
				that.setData({
					totalCount:res.total,
					yeshu: yeshu
				})
				that.show_page();
			}
		})
},
//每页显示的数据
show_page(e) {
		var that = this,
			page_now = this.data.page_now,
			pageSize = this.data.pageSize;
		db.collection('Person_DB')
			.orderBy('strdate', 'desc')
			.skip(page_now * pageSize) //从第几个数据开始
			.limit(pageSize)
			.get().then(res => {
				console.log(res);
				if (res.data.length != 0) {
					that.setData({
						Person_info: res.data
					})
				} else {
					wx.showModal({
						content: '没有找到相关资料',
						showCancel: false
					})
				}
			});
},
topClick() {
		console.log("上一页");
		var page_now = this.data.page_now-1;
		if(page_now<0){
			app.show_win("已是第一页")
			return;
		}
		this.setData({
			page_now: page_now
		})
		this.show_page();
	},
	downClick() {		
		console.log("下一页")
		var page_now = this.data.page_now+1;		
		if(page_now>=this.data.yeshu){
			app.show_win("已是最后一页")
			return;
		}
		this.setData({
			page_now: page_now
		})
		this.show_page();
	},

.pagenum {
	font-size: calc(28vmin / 7.5);
	text-align: center;
	margin-top: calc(40vmin / 7.5);
	margin-bottom: calc(40vmin / 7.5);
}

.pagenum label {
	margin-left: calc(40vmin / 7.5);
}

.topcl {
	width: calc(130vmin / 7.5);
	line-height: calc(70vmin / 7.5);
	display: inline-block;
	background: #C0C0C0;
	border-radius: 7px
}

<block wx:if="{{Person_info.length!=0}}">
	<view class="pagenum">
		<text>共{{yeshu}}页/当前{{page_now+1}}页</text>
		<block wx:if="{{yeshu!=1}}">
			<label bindtap="topClick" class="topcl">上一页</label>
			<label bindtap="downClick" class="topcl">下一页</label>
		</block>
	</view>
</block>

<label style="width: 60rpx;font-size: 30rpx;font-weight: bold;">{{(page_now)*pageSize+(index+1)}}</label>