如何在解散时从模态视图控制器传回数据
我按照这里的说明操作，但我仍然不确定这一部分：
modalVC.delegate=self; self.presentViewController(modalVC, animated: true, completion: nil) 我已尝试以编程方式实例化视图控制器，但仍无济于事。
这是解雇模态视图控制器时的代码：
@IBAction func dismissViewController(_ sender: UIBarButtonItem) { self.dismiss(animated: true) { // } }
我正在使用故事板来模拟视图。
这是我希望传输回父视图控制器的数据：
var typeState = "top" var categoryState = "casual"
这是两个String值。
编辑：
我试图从模态视图控制器传递数据，如下所示：
@IBAction func dismissViewController(_ sender: UIBarButtonItem) { self.dismiss(animated: true, completion: nil) delegate?.sendValue(value: "success") if let presenter = presentingViewController as? OOTDListViewController { presenter.receivedValue = "test" } }
而在父视图控制器上，我这样做：
func sendValue(value: NSString) { receivedValue = value as String } @IBAction func printReceivedValue(_ sender: UIButton) { print(receivedValue) }
当我点击打印按钮时，我仍然无法获得任何值。
模态视图控制器：
protocol ModalViewControllerDelegate { func sendData(typeState: String, categoryState: String) } var delegate:ModalViewControllerDelegate! var typeState = "top" var categoryState = "casual" @IBAction func dismissViewController(_ sender: UIBarButtonItem) { self.dismiss(animated: true, completion: nil) delegate?.sendData(typeState: typeState as String, categoryState: categoryState as String) }
父视图控制器：
class parentViewController: UICollectionViewController, ModalViewControllerDelegate { var typeState: String? var categoryState: String? func sendData(typeState: String, categoryState: String) { self.typeState = typeState as String self.categoryState = categoryState as String } @IBAction func printReceivedValue(_ sender: UIButton) { print(typeState) }
编辑：
这是我的新代码，不使用委托方法：
模态视图控制器：
@IBAction func dismissViewController(_ sender: UIBarButtonItem) { self.dismiss(animated: true, completion: nil) if let presenter = presentingViewController as? OOTDListViewController { presenter.typeState = typeState presenter.categoryState = categoryState } }
OOTDListViewController：
@IBAction func presentModalView(_ sender: UIBarButtonItem) { let modalView = storyboard?.instantiateViewController(withIdentifier: "filterViewController") as! ModalViewController let navModalView: UINavigationController = UINavigationController(rootViewController: modalView) self.present(navModalView, animated: true, completion: nil) } @IBAction func printValue(_ sender: UIButton) { print(typeState) print(categoryState) }
根据您要传递的数据，您可以在呈现视图控制器中创建一个属性，您可以在解除模态视图控制器时设置该属性，这样您就可以省去代理。
例如，你有一个ContactsViewController ，持有var contacts: [Contact] = []属性。 如果要创建新联系人，可以使用创建新Contact对象所需的不同值来提供模态视图控制器。 当您完成并想要关闭视图控制器时，您可以像在代码中一样调用该函数，但在ContactsViewController设置该属性。 它看起来像这样：
@IBAction func dismissViewController(_ sender: UIBarButtonItem) { if let presenter = presentingViewController as? ContactsViewController { presenter.contacts.append(newContact) } dismiss(animated: true, completion: nil) }
编辑：
如果您不想使用委托，这就是您的方法：
在您的OOTDListViewController ：
var testValue: String = "" @IBAction func printReceivedValue(_ sender: UIButton) { print(testValue) }
在你的模态视图控制器（我将它称为PresentedViewController ）：
@IBAction func dismissViewController(_ sender: UIBarButtonItem) { // if your OOTDListViewController is part of a UINavigationController stack, this check will probably fail. // you need to put a breakpoint here and check if the presentingViewController is actually a UINavigationController. // in that case, you will need to access the viewControllers variable and find your OOTDListViewController if let presenter = presentingViewController as? OOTDListViewController { presenter.testValue = "Test" } dismiss(animated: true, completion: nil) }
如果您想使用委托，这是如何做到的：
在您的OOTDListViewController中：
protocol ModalDelegate { func changeValue(value: String) } class OOTDListViewController: ModalDelegate { var testValue: String = "" @IBAction func presentViewController() { // here, you either create a new instance of the ViewController by initializing it, or you instantiate it using a storyboard. // for simplicity, I'll use the first way // in any case, you cannot use a storyboard segue directly, bevause you need access to the reference of the presentedViewController object let presentedVC = PresentedViewController() presentedVC.delegate = self present(presentedVC, animated: true, completion: nil) } func changeValue(value: String) { testValue = value print(testValue) }
}
在PresentedViewController ：
class PresentedViewController { var delegate: ModalDelegate? var testValue: String = "" @IBAction func dismissViewController(_ sender: UIBarButtonItem) { if let delegate = self.delegate { delegate.changeValue(testValue) } dismiss(animated: true, completion: nil) } }
您需要在dismissViewController方法中调用委托方法
@IBAction func dismissViewController(_ sender: UIBarButtonItem) { delegate?.sendData(typeState: "top", categoryState: "casual") self.dismiss(animated: true) { // } }
在你Modal ViewController类创建委托
var delegate: MyProtocol?
在MyProtocol中创建一个方法名称为sendData的协议，并在presentConController中为您指定委托，实现MyProtocol方法
protocol MyProtocol: class { func sendData(typeState: String, categoryState: String) } class ViewController: UIViewController, MyProtocol { var typeState: String? var categoryState: String? func sendData(typeState: String, categoryState: String) { self.typeState = typeState self.categoryState = categoryState } }
我正在使用tabbar，所以工作代码如下
if let tabBar = self.presentingViewController as? UITabBarController { let homeNavigationViewController = tabBar.viewControllers![0] as? UINavigationController let homeViewController = homeNavigationViewController?.topViewController as! HomeController homeViewController._transferedLocationID = self.editingLocationID! }