小程式中獲取當前data定義的值，用this.data.xxx

setData的時候要修改的值是不需要加this.data.xxx的，直接xxx,

一般直接修改data的值直接修改，修改陣列中物件的值或者物件的屬性值都要先轉為字串再加中括號，如果有變數可以用ES6的模版字串反單引號或者字串拼接一下。

Page({
  data: {
    currentValue:"aa",
    todoLists:[
      {
        detail:"",
        date:"",
        location:"",
        priority:"",
        remark:"",
        dateStatus:false,
        locationStatus:false,
        dateRepeat:false,
        completeStatus: false,
        currentInput:'',
      },
      {
        detail: "",
        date: "",
        location: "",
        priority: "",
        remark: "",
        dateStatus: false,
        locationStatus: false,
        dateRepeat: false,
        completeStatus: false,
        currentInput:'',
      }
    ],
    aa:{
      a:1,
      b:2
    }
  },
  tickToComplete:function(e){
    //修改陣列中物件的值
    let index = e.currentTarget.dataset.index;
    let completeStatus = `todoLists[${index}].completeStatus`;
    this.setData({
      [completeStatus]: !this.data.todoLists[index].completeStatus
    })
    //修改物件中的屬性值
    this.setData({
      ['aa.a']: 3
    })
    console.log(this.data.aa.a); //3
    //修改普通data值
    this.setData({
     currentValue: "bbb"
    })
  },