ios – 在swift中关闭模态viewController时传递数据

我试图将数据从模态ViewController传递到他的源ViewController.我想我必须使用授权,但不行.

protocol communicationControllerCamera{
    func backFromCamera()
}

class Camera: UIViewController{
    var delegate: communicationControllerCamera

    init(){
        self.delegate.backFromCamera()
    }
}


class SceneBuilder: UIViewController,communicationControllerCamera{
    func backFromCamera(){    // Never called
        println("YEAHH")
    }
}

backFromCamera方法它没有被调用.我做错了什么？

解决方法

你没有设置一个代理,所以当你尝试回调FromCamera()时它是空的.

这是一个简单的工作示例,您可以测试.请注意使用可选类型(？)作为委托.

// Camera class
protocol communicationControllerCamera {
    func backFromCamera()
}

class Camera: UIViewController {
    var delegate: communicationControllerCamera? = nil

    override func viewDidLoad() {
        super.viewDidLoad()
        self.delegate?.backFromCamera()
    }
}



// SceneBuilder class
class SceneBuilder: UIViewController,communicationControllerCamera {

   override func viewDidLoad() {
       super.viewDidLoad()
   }

   override func viewDidAppear(animated: Bool) {
       super.viewDidAppear(animated)

       var myCamera = Camera()
       myCamera.delegate = self

       self.presentModalViewController(myCamera,animated: true)
   }

   func backFromCamera() {
       println("Back from camera")
   }
}

您可以在Apple’s Swift documentation找到所需的所有信息.