IOS Swift：如何在两个控制器之间传输数据

Posted 2023-03-22

【中文标题】IOS Swift：如何在两个控制器之间传输数据

【英文标题】：IOS Swift : How to transfer data between two controllers

【发布时间】：2015-04-22 10:05:22

【问题描述】：

我尝试使用 segue 方法将数据从一个控制器传递到另一个控制器。 我的第一个视图控制器是

class ViewController: UIViewController 

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) 
        if (segue.identifier == "btnSubmitSegue") 
            var svc = segue.destinationViewController as ForthViewController;
            svc.dataParsed = "this is new text"
        
    

在目标视图控制器中 ->

class ForthViewController: UIViewController 

    @IBOutlet weak var mylabel1: UILabel!
    var dataParsed:String!

    override func viewDidLoad() 
        super.viewDidLoad()
        NsLog(dataParsed)
        mylabel1.text =  dataParsed

    

但数据未加载到目标控制器中的 mylabel1.text。你能帮忙弄清楚吗

【问题讨论】：

尝试将代码移至 viewDidAppeare 方法

NSLog 记录什么？ （顺便说一句，你应该使用 swift 函数println()。）

您的 (segue.identifier == "btnSubmitSegue") 条件是否为真？拼写错误的标识符是我的常见错误

打印出来的数据是什么意思？它打印正确吗？下次使用 println() 代替 NSLog

How do you share data between view controllers and other objects in Swift?的可能重复

【参考方案1】：

您必须在一个表格视图控制器中编写以下代码

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) 
    if segue.identifier == "show" 
        if let indexPath = self.tableView.indexPathForSelectedRow() 
            let object = self.fetchedResultsController!.objectAtIndexPath(indexPath) as! NSManagedObject
            let controller = (segue.destinationViewController as! UINavigationController).topViewController as! DetailViewController //DetailViewController
                controller.detailItem = object
                println(object)
        
    

在第二个视图控制器中

    override func viewDidLoad() 
    super.viewDidLoad()
    // Do any additional setup after loading the view.
    configureView()
   


    var detailItem: AnyObject? 
    didSet 
        // Update the view.
        self.configureView()
    


func configureView() 
    // Update the user interface for the detail item.
    if let detail: AnyObject = detailItem 
        if var textView = self.text 
            textView.text! = detail.valueForKey("mynote")!.description
        

    

希望对你有所帮助。

【参考方案2】：

试试看：

class FirstViewController: UIViewController 

    private var myStringData = "This is my Data"

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) 
        var destView: SecondViewController = segue.destinationViewController as! SecondViewController
        destView.data = myStringData
    

它们是你的目标视图控制器：

class SecondViewController: UIViewController 

    var data: String?

    @IBOutlet weak var labelWhereDataWillAppear: UILabel!

    override func viewDidLoad() 
        labelWhereDataWillAppear.text = data!
        print("\(data!)")
    

【参考方案3】：

  override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) 


   if segue.identifier == "currencySegue"

        let controller = segue.destinationViewController as! SubmitDropMenuDetailedTableViewController
        controller.currencyId = Int(self.currencyTypeId)
        controller.entity = "Currency"
        controller.delegate = self
    
    else if segue.identifier == "categorySegue"
        let controller = segue.destinationViewController as! SubmitDropMenuDetailedTableViewController
        controller.entity = "Category"
        controller.categoryId = Int(expenseTypeId)
        controller.delegate = self