快速使用从一个类到另一个类的内部函数

Question

我有个人资料课程和设置课程

配置文件类包含一个内部函数

class Profile: UIViewController,UIImagePickerControllerDelegate,UINavigationControllerDelegate {

   internal func profileSelectFromGallery(sender: Profile){
        let myPickerController = UIImagePickerController()
        myPickerController.delegate = sender;
        myPickerController.sourceType =
            UIImagePickerControllerSourceType.PhotoLibrary
        sender.presentViewController(myPickerController, animated:true, completion: nil)
    }
}

我想在设置类中使用profileSelectFromGallery，下面有两次尝试

class SettingsVC: UITableViewController {
   // I will call this private function on a click events
   private func selectFromGallery(){

            // let profile = Profile()
            // profile.profileSelectFromGallery(self)
            Profile.profileSelectFromGallery(self)

   }
}

上面的代码导致Cannot convert value of type 'SettingsVC' to expected argument type 'Profile'因为profileSelectFromGallery需要一个类Profile的参数，所以我要做的是更改发送方，以便可以从我的任何类中使用它，并且不只是我的个人资料课 。

Answer 1

因此，问题在于您无法将SettingsVC转换为Profile 。 如果您查看方法签名，将会看到它需要一个Profile ：

internal func profileSelectFromGallery(sender: Profile)

您正在尝试在selectFromGallery()传递SettingVC

在profileSelectFromGallery内部，您希望发送方既是UIViewController又是UIImagePickerControllerDelegate 。 您可以通过以下几种方法进行操作：

最简单的是更改方法签名。 您将执行以下操作：

   internal func profileSelectFromGallery(sender: UIImagePickerControllerDelegate){
        guard let vc = sender as? UIViewController else {
           return
        }

        let myPickerController = UIImagePickerController()
        myPickerController.delegate = sender;
        myPickerController.sourceType =
            UIImagePickerControllerSourceType.PhotoLibrary
        vc.presentViewController(myPickerController, animated:true, completion: nil)
    }

这里有presentViewController ：将sender更改为适当的委托方法，并通过guard声明将其presentViewController为presentViewController调用的VC。

做到这一点的更棒的方法是使用协议扩展！

extension UIImagePickerControllerDelegate where Self: UIViewController, Self: UINavigationControllerDelegate {
    func profileSelectFromGallery() {
        let myPickerController = UIImagePickerController()
        myPickerController.delegate = self
        myPickerController.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        self.presentViewController(myPickerController, animated:true, completion: nil)
    }
}

基本上，我在这里所做的就是为每个UIImagePickerControllerDelegate添加一个方法，即UIViewController和UINAvigationControllerDelegate 。 这意味着我可以在Profile和SettingVC上都调用它（一旦您将必要的委托添加到SettingVC）。 您需要做的只是：

let profile = Profile()
profile.profileSelectFromGallery()

let settingVC = SettingVC()
settingVC.profileSelectFromGallery()

Answer 2

将新协议声明为：

protocol PickerProtocol : UIImagePickerControllerDelegate, UINavigationControllerDelegate {

}

现在，您的Profile类将如下所示：

class Profile: UIViewController, PickerProtocol {

//Option 1
internal func profileSelectFromGallery(contoller: UIViewController, pickerProtocol: PickerProtocol){

    let myPickerController = UIImagePickerController()

    myPickerController.delegate = pickerProtocol

    myPickerController.sourceType =
        UIImagePickerControllerSourceType.PhotoLibrary
    contoller.presentViewController(myPickerController, animated:true, completion: nil)
}

//Option 2
internal func profileSelectFromGalleryOption2(sender : UIViewController? ) {

    var viewContoller : UIViewController = self
    if let unwrappedSender = sender {
        viewContoller = unwrappedSender
    }

    let myPickerController = UIImagePickerController()

    if let pickerProtocol = viewContoller as? PickerProtocol {
        myPickerController.delegate = pickerProtocol
    } else {
        myPickerController.delegate = self //Assign self as default
    }

    myPickerController.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
    viewContoller.presentViewController(myPickerController, animated:true, completion: nil)
}

}

class SettingsVC1: UITableViewController {
    // I will call this private function on a click events
    private func selectFromGallery(){

        let profile = Profile()
        profile.profileSelectFromGallery(self, pickerProtocol:profile)
        profile.profileSelectFromGalleryOption2(self)
        //Or
        profile.profileSelectFromGalleryOption2(nil)//profile itself delegate and presenting controller
    }
}

// 要么

class SettingsVC2: UITableViewController, PickerProtocol {
    // I will call this private function on a click events
    private func selectFromGallery(){

        let profile = Profile()
        profile.profileSelectFromGallery(self, pickerProtocol:self)
        profile.profileSelectFromGalleryOption2(self)
        //Or
        profile.profileSelectFromGalleryOption2(nil)//profile itself delegate and presenting controller
    }
}

Answer 3

我会这样使用POP（面向协议的程序设计）：

protocol SelectorProtocol: UIImagePickerControllerDelegate, UINavigationControllerDelegate {
}

extension SelectorProtocol where Self: UIViewController {
    func profileSelectFromGallery() {
        let myPickerController = UIImagePickerController()
        myPickerController.delegate = self;
        myPickerController.sourceType = UIImagePickerControllerSourceType.PhotoLibrary
        self.presentViewController(myPickerController, animated:true, completion: nil)
    }
}

class Profile: UIViewController,UIImagePickerControllerDelegate,UINavigationControllerDelegate, SelectorProtocol {
    func foo() {
        profileSelectFromGallery()
    }
}

class SettingsVC: UITableViewController, SelectorProtocol {
    // I will call this private function on a click events
    private func selectFromGallery(){
        profileSelectFromGallery()
    }
}

Answer 4

您正在尝试静态调用profileSelectFromGallery:即使它是一个实例方法。

尝试将方法定义更改为：

internal static func profileSelectFromGallery(sender: Profile){

至于能够将任何类用作委托，请创建自定义Protocol并确保sender符合此协议。 有关更多信息，请参见此处（特别是标题为Protocols的标题）： http : //www.raywenderlich.com/115300/swift-2-tutorial-part-3-tuples-protocols-delegates-and-table-views

Answer 5

也许以下方法会起作用：

   class SettingsVC: UITableViewController {
   // I will call this private function on a click events
   private func selectFromGallery(){
       let prof = Profile()
       prof.profileSelectFromGallery(prof)
   }
}