微信小程序如何把一个页面的某个数据传到另一个页面去

Question

在首页明细这里，通过相加后变化数据的支出部分，将他的数据动态的传递给另一个页面，麻烦用代码讲讲，因为支出总额要随下面增加的账单而变化，用全局变量能实现吗？

Answer 1

Hi~ 少年我又带着不是最优解的案例来了。
简陋的效果:

粗糙的代码:
index/index.wxml

<view>总支出: {{totalExpenditure}} 元</view>
<view>支出条目</view>
<view wx:for="{{billFlow}}" wx:key="unique">
  {{item.content}} {{item.price}}元
</view>

index/index.js

const app = getApp()

Page({
  data: {
    totalExpenditure: 0,
    billFlow: []
  },
  onShow() {
    this.setData({
      totalExpenditure: app.totalExpenditure(),
      billFlow: app.billFlow
    })
  }
})

index2/index.wxml

<view>剩余预算: {{remainingBudget}}</view>
<view>本月预算: {{budget}}</view>
<view>本月支出: {{totalExpenditure}}</view>

<view bindtap="pay" wx:for="{{goods}}" wx:key="unique" data-price="{{item.price}}" data-content="{{item.content}}">买{{item.content}} {{item.price}} 元</view>

index2/index.js

const app = getApp()

Page({
  data: {
    totalExpenditure: 0,
    remainingBudget: 0,
    budget: 0,
    billFlow: [],
    goods: [
      {
        content: '棒棒糖',
        price: 1,
      },
      {
        content: '口香糖',
        price: 2,
      }
    ]
  },
  onShow() {
    this.setData({
      totalExpenditure: app.totalExpenditure(),
      billFlow: app.billFlow,
      budget: app.budget,
      remainingBudget: app.remainingBudget()
    })
  },
  pay(e) {
    const { price, content } = e.currentTarget.dataset;
    app.billFlow.push({
      content,
      price: -1 * price
    })
    this.onShow()
  }
})

app.js

App({
  // 预算
  budget: 100,
  // 账单流水
  billFlow: [
    {
      content: '餐饮',
      price: -73
    }
  ],
  // 总支出
  totalExpenditure() {
    return Math.abs(this.billFlow.filter(f => f.price < 0).reduce((t, i) => t + i.price, 0))
  },
  // 剩余预算 
  remainingBudget(){
    return this.budget - this.totalExpenditure();
  }
})

https://developers.weixin.qq.com/s/2gupefmd7SCi