快速检测UILabel文本更改 [英] Detect UILabel text change in swift

问题描述

是否有一种方法可以在UILabel的文本发生更改时得到通知，或者最好将userInteractionEnabled设置为false的UITextField并使用其UIControlEditingChanged事件来获得通知达到我的目的?

Is there a way to get notified when there is a change in a UILabel's text or would I be better off using a UITextField with userInteractionEnabled set to false and using its UIControlEditingChanged event to fulfil my purpose?

例如每次更改UILabel的文本时，我都需要运行某些代码行，并相应地进行更改.因此，我不想在每次更改UILabel的文本时都写这100行几乎相似的代码，而是希望将其一起写在一个地方，并在每次UILabel更改时调用它.我什至不知道这是否有意义.原谅我，但我不能透露很多代码.

For ex. I need to run certain lines of code every time I change the UILabel's text and accordingly. So instead of writing those 100 lines of almost similar code for every case I change the UILabel's text, I wish to write it together in one place and call it every time the UILabel is changed. I don't even know if that makes any sense. Forgive me but I cannot expose much of the code.

推荐答案

创建一个从UILabel继承的类.如:

Create a class that inherits from UILabel. Such as:

class YourLabel: UILabel {

    override var text: String? {
        didSet {
            if let text = text {
                println("Text changed.")
            } else {
                println("Text not changed.")
            }
        }
    }
}

为您的对象创建此类的出口.

Create a outlet of this class for your object.

@IBOutlet weak var label: YourLabel!
label.text = "abc"

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