lineSpacing UILabel的属性？(Is lineSpacing a property of UILabel?)

lineSpacing UILabel的属性？(Is lineSpacing a property of UILabel?)

我有一个属性lineSpacing安装的UILabel的子类，如下所示：

var lineSpacing = CGFloat(20.0)

当我这里有这个时候，它会推动文本，即使它不用于任何东西，我删除了除该属性外的所有代码：

class CustomLabel : UILabel { var lineSpacing = CGFloat(20.0) }

它仍然被推高，我改变了财产的名称，并修复它，我只是想知道这是从哪里来的，因为我无法从UILabel访问lineSpacing

regularLabel.lineSpacing

给出错误。

I have a subclass of UILabel with a property lineSpacing setup like so:

var lineSpacing = CGFloat(20.0)

When I have this here it pushes up the text, even though it isn't used for anything, I removed all the code except for that property:

class CustomLabel : UILabel { var lineSpacing = CGFloat(20.0) }

and it is still pushed up, I changed the name of the property and it fixed it, I was just wondering where this is coming from as I can't access lineSpacing from a UILabel

regularLabel.lineSpacing

gives an error.

最满意答案

是的， UILabel有一个无证的非公开lineSpacing属性。 您可以在从运行时Objective-C元数据创建的头文件中看到它：

https://github.com/nst/iOS-Runtime-Headers/blob/master/Frameworks/UIKit.framework/UILabel.h

由于它不是公开的，因此如果将它提交给App Store，则覆盖它（即使意外）可能会导致Apple拒绝您的应用程序。

Yes, UILabel has an undocumented, non-public lineSpacing property. You can see it in this header file that was created from the runtime Objective-C metadata:

https://github.com/nst/iOS-Runtime-Headers/blob/master/Frameworks/UIKit.framework/UILabel.h

Since it's not public, overriding it (even accidentally) may cause Apple to reject your app if you submit it to the App Store.