ios - 数据没有从一个 View Controller 传递到另一个

Question

当我尝试将一些变量从一个 VC 传递到另一个时，我传递到的 VC 中的变量没有得到更新。到目前为止，这是我的做法:

VC 1

var note: String = ""
var reward: Int = 0
var deadline: Int = 0

VC 2

var vcOne = VcOne()
var note: String = "Some note..."
var reward: Int = 100
var deadline: Int = 988934

在我弹出 VC 2 的函数中，我从那个函数传递数据来更新 VC 1，如下所示:

func passData()
{
    vcOne.note = self.note
    vcOne.reward = self.reward
    vcOne.deadline = self.deadline

    navigationController?.popViewController(animated: true)
}

但是当我通过后打印VC 1中的值时，它们仍然是空的或0。

以前用过这种方法传数据，这次好像不行了。我应该做不同的事吗？像我展示的那样传递数据的最佳方式是什么？

编辑:这是我的真实代码

VC 1:

class CreateMissionController: UIViewController, UITextViewDelegate
{
    var deadline: Int = 0
    var missionLatitude: Double = 0
    var missionLongitude: Double = 0


func handleSetLocation()
{
    let createMapController = CreateMapController()
    navigationController?.pushViewController(createMapController,animated: true)
}

VC 2

class CreateMapController: UIViewController, CLLocationManagerDelegate,     MKMapViewDelegate
{
    var createMissionController: CreateMissionController?
    var missionLatitude: Double?
    var missionLongitude: Double?
    var deadline: Int?


func handleChooseLocation()
{
    missionLatitude = missionLocation!.latitude
    missionLongitude = missionLocation!.longitude

    createMissionController?.missionLatitude = missionLatitude!
    createMissionController?.missionLongitude = missionLongitude!

    let timeInterval = deadlineDate?.timeIntervalSince1970
    let deadlineInt = Int(timeInterval!)

    createMissionController?.deadline = deadlineInt

    print(missionLatitude!)
    print(missionLongitude!)
    print(deadlineInt)

    navigationController?.popViewController(animated: true)
}

当我在 VC 2 中打印时，它们显示正确的值，但如果我在 VC 2 中执行完函数后尝试在 VC 1 中打印，它们只会打印默认值。

Answer 1

VC1

var note: String = ""
var reward: Int = 0
var deadline: Int = 0

var vc2 = VcTwo()
vc2.vcOne = self 

VC 2

var vcOne : VcOne
var note: String = "Some note..."
var reward: Int = 100
var deadline: Int = 988934

func passData()
{
    vcOne.note = self.note
    vcOne.reward = self.reward
    vcOne.deadline = self.deadline

    navigationController?.popViewController(animated: true)
}

正如我在评论中提到的，您正在重新分配一个新的 vcOne，因此您设置了另一个对象并且没有取回数据。通过将 vc2.vcOne 分配给 self，您告诉 vc2 使用您当前的对象