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
}
}
}