currentPlanChanged:async function(e){ let i = e.detail.value let plans = this.data.prices.plans let plan = plans[i] if(plan.name==this.data.plan)return let res = await wx.showModal({ cancelColor: 'cancelColor', title:'是否修改？', content:'修改当前的会员套餐' }) if(res.confirm){}else return console.log('时间打印：',this.data.realToday) let buyDate = this.data.expireDate > this.data.realToday ? this.data.expireDate : this.data.realToday let expireDate = lib.getDateByDeltaMonth(buyDate, plan.month) this.renderData({ plan:plan.name, buyDate, expireDate }) }这个函数无法正常设置日期，会显示错误，什么原因？这是另外一个函数function getDateByDeltaMonth(startDate, n) { var date = new Date(startDate) var m = date.getMonth() date.setMonth(m + n) var y = date.getFullYear() m = date.getMonth() + 1 var d = date.getDate() return y + '-' + (m < 10 ? '0' + m : m) + '-' + (d < 10 ? '0' + d : d) + '' }

这段代码中，`lib.getDateByDeltaMonth` 函数的参数 `startDate` 和 `buyDate` 都是字符串类型，需要转换成 Date 类型才能进行日期计算。你可以在函数内部通过 `new Date(startDate)` 和 `new Date(buyDate)` 进行转换。

修改后的代码如下：

function getDateByDeltaMonth(startDate, n) {
  var date = new Date(startDate)
  var m = date.getMonth()
  date.setMonth(m + n)
  var y = date.getFullYear()
  m = date.getMonth() + 1
  var d = date.getDate()
  return y + '-' + (m < 10 ? '0' + m : m) + '-' + (d < 10 ? '0' + d : d) + ''
}

async function currentPlanChanged(e) {
  let i = e.detail.value
  let plans = this.data.prices.plans
  let plan = plans[i]
  if (plan.name == this.data.plan) return
  let res = await wx.showModal({
    cancelColor: 'cancelColor',
    title: '是否修改？',
    content: '修改当前的会员套餐'
  })
  if (res.confirm) {
    let buyDate = new Date(this.data.expireDate) > new Date(this.data.realToday) ? this.data.expireDate : this.data.realToday
    let expireDate = getDateByDeltaMonth(buyDate, plan.month)
    this.renderData({
      plan: plan.name,
      buyDate,
      expireDate
    })
  } else {
    return console.log('时间打印：', this.data.realToday)
  }
}