ios - 从不同的 View 更改 View textLabel

Question

我有一个名为 colorChangerViewClass 的自定义类，它继承自 UIView:

class colorChangerViewClass: UIView {


@IBOutlet weak var controller: ViewController!

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    // I want to change a textLabel in the main ViewController based on the current finger position here!
    }

override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
    // And here aswell!
}

override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) { ... }


func setColor(color: UIColor) {
    self.backgroundColor = color
}

}

在 touchesBegan 和 touchesMoved 方法中，我想根据当前手指更改主 ViewController(不同的)中的 textLabel位置。

在 colorChangerViewClass 和 ViewController 这两个类之间建立通信的最佳方式是什么？

Answer 1

在您的情况下，您正在尝试与 child 沟通，您可以通过多种方式获得所需的输出。

1.授权

<强>2。通知

<强>3。将父实例对象传递给子对象(类似于委托(delegate))

我正在用委托(delegate)进行演示，您可以将委托(delegate)用作:-

<强>1。声明 在 ColorChangerViewClass 之外的某处声明一个协议(protocol)

protocol ColorChangerViewClassDelegate:class {
    func fingerDidMoved()
    }

<强>2。在 ColorChangerViewClass 中创建委托(delegate)变量

class ColorChangerViewClass: UIView {

        //declare delegate var

        weak var delegate:ColorChangerViewClassDelegate?

        @IBOutlet weak var controller: ViewController!

        override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
            // I want to change a textLabel in the main ViewController based on the current finger position here!
            self.notify()

        }

        override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {

            self.notify()
            // And here aswell!
        }

        override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {


        }

        func setColor(color: UIColor) {
            self.backgroundColor = color
        }

        func notify() {
            if let delegate = self.delegate {
                delegate.fingerDidMoved()
            }
        }

        }

<强>3。将您的 View 委托(delegate)给 Controller

class SomeVC:UIViewController,ColorChangerViewClassDelegate {

    var myLabel = UILabel()
        override func viewDidLoad() {
            super.viewDidLoad()

            //your view
            let theView = ColorChangerViewClass() // you might need auto layout or frame declared on your view to define view size
            theView.delegate = self
        }

        //MARK:-deleate method of view
        func fingerDidMoved() {
           // set text from here 
           self.myLabel.text = "Your text"
        }
    }