我基本上有一个Notes应用程序,我试图从另一个视图控制器中调用一个函数。我该怎么做,还是应该有更好的方法呢?

这是我试图从中调用函数的地方

class NoteDetailViewController: UIViewController
{
    @IBOutlet weak var funcButton: UIButton!

    @IBAction func funcButTouched(sender: UIButton)
    {
     // where i want to call the function
    }
}


功能在哪里

class ListTableViewController: UITableViewController
{
    // the function
    func wordCount()
    {
        var contentArr = Project.sharedInstance.content.componentsSeparatedByString(" ")
        for (index, element) in contentArr.enumerate()
        {
            let location = conciseArr.indexOf(element)
            if (location != nil)
            {
                contentArr[index] = inflatedArr[location!]
                afterStr = contentArr.joinWithSeparator(" ")
                Project.sharedInstance.after = afterStr
            }
        }
    }
}


我试过只是创建ListTableViewController的实例,然后以这种方式调用该函数,但出现错误。

最佳答案

您可以使用delegation

首先,声明一个委托协议。这应该在您的NoteDetailViewController.swift文件中,但在class声明之外:

protocol NoteDetailViewControllerDelegate: class {
    func noteDetailViewControllerButtonTouched(controller: NoteDetailViewController)
}


接下来,将一个委托属性添加到您的NoteDetailViewController中:

weak var delegate: NoteDetailViewControllerDelegate?


现在,我们使用@IBAction告诉委托人,这将是ListTableViewController

@IBAction func funcButTouched(sender: UIButton)
{
    delegate?.noteDetailViewControllerButtonTouched(self)
}


最后,回到ListTableViewController(假设此控制器是显示NoteDetailViewController之前的控制器),遵循协议并使用prepareForSegue将委托设置为其自身:

class ListTableViewController: UITableViewController, NoteDetailViewControllerDelegate {
    // ... more stuff ...

    // Implement the delegate protocol
    func noteDetailViewControllerButtonTouched(controller: NoteDetailViewController) {
        // Do something! The button was pressed!
        wordCount()
    }
    // Set ourselves as delegate when we are about to show the other view controller
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if let yourVC = segue.destinationViewController as? NoteDetailViewController {
            yourVC.delegate = self
        }
    }
}




您应该完成以下操作:

NoteDetailViewController.swift

class NoteDetailViewController: UIViewController
{
    @IBOutlet weak var funcButton: UIButton!
    weak var delegate: NoteDetailViewControllerDelegate?

    @IBAction func funcButTouched(sender: UIButton)
    {
        delegate?.noteDetailViewControllerButtonTouched(self)
    }
}

protocol NoteDetailViewControllerDelegate: class {
    func noteDetailViewControllerButtonTouched(controller: NoteDetailViewController)
}


ListTableViewController.swift

class ListTableViewController: UITableViewController, NoteDetailViewControllerDelegate
{
    // the function
    func wordCount()
    {
        var contentArr = Project.sharedInstance.content.componentsSeparatedByString(" ")
        for (index, element) in contentArr.enumerate()
        {
            let location = conciseArr.indexOf(element)
            if (location != nil)
            {
                contentArr[index] = inflatedArr[location!]
                afterStr = contentArr.joinWithSeparator(" ")
                Project.sharedInstance.after = afterStr
            }
        }
    }
    // Implement the delegate protocol
    func noteDetailViewControllerButtonTouched(controller: NoteDetailViewController) {
        // Do something! The button was pressed!
        wordCount()
    }
    // Set ourselves as delegate when we are about to show the other view controller
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if let yourVC = segue.destinationViewController as? NoteDetailViewController {
            yourVC.delegate = self
        }
    }
}

10-07 19:05
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