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UI元素未显示,变量来自segue

ckrecord segue uilabel swift ios

-1

Jon · 技术社区 · 9 年前

控制器一,保存CK记录“详细信息”。控制器一中的一个按钮连接到另一个控制器。我已经为这个逻辑设置了下面的序列。。。

@IBAction func booton(_ sender: Any) {
    func prepareForSegue(segue: UIStoryboardSegue, sender: Any?)
    {
        if segue.identifier == "lastsegue"
        {
          if let destination = segue.destination as? FoodDetail01
          {
            let lastreservation = detail.value(forKey: "Reservation") as? String
            let lasttake = detail.value(forKey: "Take") as? String

            destination.reservation = lastreservation
            destination.take = lasttake
        }...

在控制器2中,我有以下接收变量和设置为这些新变量的标签。

import UIKit

class FoodDetail01: UIViewController {

     var reservation: String!
     var take: String!

@IBOutlet weak var reservationlabel: UILabel!
@IBOutlet weak var takelabel: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()

    self.reservationlabel.text = reservation
    self.takelabel.text = take
}

然而,这给我带来了问题,当我运行这段代码时,控制器2中没有出现标签(正确连接)。如图所示。

Missing Labels

我这里出了什么问题?

3 回复 | 直到 9 年前

Nirav D 9 年前

您已添加 prepareForSegue 你的内心 booton 但它应该与其他类级方法一起使用。

@IBAction func booton(_ sender: Any) {
     //Button action code
}

//prepareForSegue is outside from that method like other method of class
override func prepareForSegue(segue: UIStoryboardSegue, sender: Any?)
{
    if segue.identifier == "lastsegue"
    {
        if let destination = segue.destination as? FoodDetail01 {
            let lastreservation = detail.value(forKey: "Reservation") as? String
            let lasttake = detail.value(forKey: "Take") as? String

            destination.reservation = lastreservation
            destination.take = lasttake
        }
        ...
    }
}

注: 在Swift中,如果使用native,则为batter Dictionary 具有 subscript 而不是 NSDictionary .

Lineesh K Mohan 9 年前

将prepareForSegue写为separatefunction,并调用performSegue来调用segue

请在SWIFT 3中查找代码

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {

    if segue.identifier == "lastsegue"
    {
      if let destination = segue.destination as? FoodDetail01
      {
        let lastreservation = detail.value(forKey: "Reservation") as? String
        let lasttake = detail.value(forKey: "Take") as? String

        destination.reservation = lastreservation
        destination.take = lasttake
      }
    }
}

@IBAction func booton(_ sender: Any) {

    self.performSegue(withIdentifier: "lastsegue", sender: self)
}

此外,请检查这些值是否为零

let lastreservation = detail.value(forKey: "Reservation") as? String
let lasttake = detail.value(forKey: "Take") as? String

Sagar Chauhan 9 年前

请更新在segue中传递字符串值的代码。添加在最后预订和最后拍摄之后。如果不加,则它传递零值。您可以通过添加断点进行检查。

@IBAction func booton(_ sender: Any) {
func prepareForSegue(segue: UIStoryboardSegue, sender: Any?)
{
    if segue.identifier == "lastsegue"
    {
      if let destination = segue.destination as? FoodDetail01
      {
        let lastreservation = detail.value(forKey: "Reservation") as? String
        let lasttake = detail.value(forKey: "Take") as? String

        destination.reservation = lastreservation!
        destination.take = lasttake!
    }...