Swift泛型类作为委托 [英] Swift Generic class as delegate

问题描述

在swift中使用泛型类作为委托时遇到问题。例如我试图使用一个通用的NSFetchedResultsDelegate定义为：

  class FetchedTableController< T：NSManagedObject> ：NSFetchedResultsControllerDelegate 
  

在课内我设置一个NSFetchedResultsController并将委托设置为self。但是由于某种原因，委托方法从未被调用。当我删除了类的通用部分时，代理人按预期的方式调用：

  class FetchedTableController：NSFetchedResultsControllerDelegate 
  

有没有办法使用泛型类作为委托？

解决方案

这似乎是在Xcode7中修复的。我可以使用通用类作为NSFetchedResultsControllerDelegate，UITableViewControllerDelegate等...甚至不需要添加@objc前缀到该类。

但是，该类还必须有一些NSObject超类。

I encountered a problem when using a generic class in swift as a delegate. for example i tried to use a generic NSFetchedResultsDelegate defined as:

class FetchedTableController<T:NSManagedObject> : NSFetchedResultsControllerDelegate

Inside the class i setup a NSFetchedResultsController and set the delegate to 'self'. But for some reason the delegate methods never got called. When i removed the Generic part of the class, the delegates got called as expected:

class FetchedTableController : NSFetchedResultsControllerDelegate

Is there a solution to use generic classes as delegate?

解决方案

This seems to be fixed at Xcode7. I can successfully use generic class as NSFetchedResultsControllerDelegate, UITableViewControllerDelegate etc. ... You don't even need to add the @objc prefix to the class.

However, the class has to still have some NSObject superclass.

这篇关于Swift泛型类作为委托的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！