ios - 在 Swift 中从 UISplitViewDetail 创建委托(delegate)到 master 时出错

Question

SWIFT/IOS 8.2我正在尝试将我的 CalculatorViewController 设置为委托(delegate)目标，以便获取数据 - 但我似乎设置错误:“EXC_BAD_ACCESS (code:2)”

(在 GraphView.swift 中)

protocol CalculatorViewDataSource: class {
    func calculateYForXEquals(sender: CalculatorViewController, currentX: CGFloat) ->CGFloat?
}

class GraphView: UIView {
    weak var calculatorViewDataSource: CalculatorViewDataSource?
    //...
}

(在 GraphViewController.swift 中)

class GraphViewController: UIViewController {
    @IBOutlet weak var graphView: GraphView! {
        didSet{
            graphView.calculatorViewDataSource = self.view.superview?.superview as CalculatorViewController
        }
    }
// ...
}

(在 CalculatorViewController.swift 中)

class CalculatorViewController: UIViewController, CalculatorViewDataSource{
    // ...
}

func calculateYForXEquals(sender: CalculatorViewController, currentX: CGFloat) ->CGFloat? {
    return nil
}

问题:

当我尝试在 GraphViewController 中设置委托(delegate)时，出现“EXC_BAD_ACCESS (code:2)”错误，导致崩溃...知道为什么吗？

我不知道如何从 CalculatorViewController 级别访问该类。这是 Storyboard:

-> SplitViewController - NavigationController - (Master) CalculatorViewController
         I
     NavigationController - (Detail) GraphViewController

Answer 1

尝试做这样的事情:

    var graphViewController: GraphViewController?

    private func setupSplitViewController() {
        let masterNavigationController: AnyObject? = splitViewController?.viewControllers.first
        graphViewController = masterNavigationController!.topViewController as? GraphViewController
        graphViewController!.graphView.calculatorViewDataSource = self
    }