然后,我尝试在第二个视图中存储对第一个视图的引用,并直接调用函数.这似乎工作：

屏幕1

class Screen1: UIViewController {
 
    var myName = "Screen1"
 
    override func viewDidLoad() {
        super.viewDidLoad()
    }
    //
    // checking if the segue to screen 2 is called and then passing a reference
    //
    override func prepareForSegue(segue: UIStoryboardSegue!,sender: AnyObject!) {
        if segue.identifier == "screen2Segue"{
            let vc = segue.destinationViewController as Screen2
            vc.storedReference = self
        }
    }
 
    func getName() -> String {
        return myName
    }
}

屏幕2

class Screen2: UIViewController {
 
    var storedReference:Screen1!
 
    override func viewDidLoad() {
        super.viewDidLoad()
    }
 
    func testReference() {
        // calling a function on the stored reference to screen 1
        var str = storedReference.getName()
        println("Leaving screen 2,going to " + str)
    }
}

我的问题：这段代码怎么了？为什么要使用代理和协议,如果你可以直接传递一个引用呢？

也许相关：视图何时被初始化并被全新的视图实例所替代？我在一个旧的实例上调用’getName()’？