Swift UITextField 子类以编程方式处理文本更改 [英] Swift UITextField subclass handle text change programmatically

问题描述

我有一个 UITextField 的子类，专门用于处理日期文本.我有一个使用此文本字段的 tableviewcell:

I have a subclass of UITextField that is specific to handle Date text. I have a tableviewcell that uses this text field:

let dateInput: DateTextField

现在控制器需要在显示之前初始化dateInput的文本如下:

Now the controller needs to initialize the text of the dateInput prior to display as follows:

cell.dateInput.text = "01/29/2016"

现在，我希望能够检测到从子类更改的文本，以便我可以更新内部日期变量，使其与文本同步.

Now, I want to be able to detect that the text changed from the subclass so that I can update the internal date variable so that is it in-sync with the text.

我实现了文本字段委托方法，但它只捕获用户所做的更改，而不是以编程方式进行的.

I implemented the textfield delegate methods but that just catches changes made by the user and not programmatically.

推荐答案

您可以覆盖属性并在您的自定义类中添加 didSet 观察者:

You can override property and add didSet observer in your custom class:

class DateTextField: UITextField {

    override var text: String? {
        didSet {
           // Do your stuff here    
        }
    }   
}

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