在swift中使用类中的内部函数到另一个类

Question

我有一个配置文件类和设置类

profile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,我在下面有两次尝试

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)

   }
}

上面的代码结果Cannot convert value of type 'SettingsVC' to expected argument type 'Profile'因为profileSelectFromGallery需要一个类的参数Profile所以我想要做的是更改发送者,以便我可以从我的任何一个类而不仅仅是我的Profile类中使用它.

Answer 1

所以问题是你无法将a转换SettingsVC成a Profile.如果您查看方法签名,您会看到它期望Profile:

internal func profileSelectFromGallery(sender: Profile)

您正在尝试传入SettingVC selectFromGallery()

在里面,profileSelectFromGallery你希望发件人既是a UIViewController又是a UIImagePickerControllerDelegate.有几种方法可以做到这一点:

最简单的是更改方法签名.你会做这样的事情:

   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)
    }

这里有两个主要内容:sender更改为正确的委托方法,并将guard语句转换为VC以进行presentViewController调用.

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)
    }
}

基本上我在这里做的是为每个人添加一个方法UIImagePickerControllerDelegate也是一个UIViewController和一个UINAvigationControllerDelegate.这意味着我可以在Profile和SettingVC上调用它(一旦你将必要的委托添加到SettingVC).你需要做的就是:

let profile = Profile()
profile.profileSelectFromGallery()

let settingVC = SettingVC()
settingVC.profileSelectFromGallery()