Swift通用变量 [英] Swift generic variable

问题描述

我有一个协议，我想有一个实现mu协议的UIViewController类型的变量。如果我尝试这样做：

I have a protocol, and I'd like to have a variable of type UIViewController implementing mu protocol. If I try to do something like:

var delegate:UIViewController<BouncingMenuDelegate>?

我收到UIViewController是非泛型类型的错误。那么问题是如何访问Objective-C中用于访问代表的模型？谢谢！

I receive error that UIViewController is a non-generic type. Then the question is being how to access the model we used in Objective-C for accessing delegates? Thank you in advance!

推荐答案

您不能在Swift中声明变量类型。

You cannot declare variable type like that in Swift.

解决问题的最简单方法是将 UIViewController 方法/属性添加到 BouncingMenuDelegate 要求： p>

The easiest way to solve your problem is adding UIViewController methods/properties to BouncingMenuDelegate requirement:

@objc protocol BouncingMenuDelegate {
    // Delegate methods
    func boudcingMenu(bouncingMenu:BouncingMenu, didSelectItemAtIndex index:Int)

    // required methods/properties from UIViewController 
    var view:UIView { get }
    var navigationController:UINavigationController? { get }
    func presentViewController(viewControllerToPresent: UIViewController, animated flag: Bool, completion: (() -> Void)?)
}

class BouncingMenu:UIView {
    weak var delegate:BouningMenuDelegate?
}

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