按钮单击使整个应用程序崩溃

Question

我目前正在构建应用程序的 UI，但不使用 IB 或情节提要。我有以下层次结构： 1. ViewController：主视图控制器。 2. DrawerViewController：是下抽屉菜单的视图控制器。 主视图控制器将抽屉视图控制器的视图添加为子视图。 3. 添加按钮：这是一个以编程方式创建并添加到drawerViewController 视图的UIButton。

问题是如果我单击添加按钮，应用程序崩溃，输出中绝对没有错误消息，除了 (lldb)。

我尝试了以下方法：

1. 更改选择器名称和方法名称。
2. 检查了选择器方法的名称。
3. 添加和删除选择器方法的参数。
4. 更改了按钮的名称。
5. 在另一个视图中添加了按钮。

没有办法使用断点来跟踪错误，因为应用程序编译得很好，并且只有在您单击按钮时应用程序才会崩溃。

这是我为显示问题而创建的测试项目的链接：

GitHub

视图控制器：

class ViewController: UIViewController //, DrawerDelegate
{

//Lower Drawer.
var drawerView: DrawerView!

var drawerViewHidden: Bool = false
var addButton: UIButton!
var viewHeight: CGFloat! = 0
var viewWidth : CGFloat! = 0
var shownDrawerViewY: CGFloat!
var hiddenDrawerViewY: CGFloat!

init()
{
    super.init(nibName: nil, bundle: nil)
}

required init(coder aDecoder: NSCoder)
{
    super.init(coder: aDecoder)
}



override func viewDidLoad()
{
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
    //Setup UI
    setUpUI()
}

override func viewWillAppear(animated: Bool)
{
    super.viewWillAppear(animated);


}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


//MARK:- UI initialization.
/**
Private function that setsup the UI.
*/
private func setUpUI()
{
    setUpDrawer()
}

//MARK: Drawer setup.

/**
A private function that programatically creataes a drawer and add it to the view.
*/
private func setUpDrawer()
{
    var controller = DrawerViewController(width: self.view.frame.width, height: self.view.frame.height)

    self.view.addSubview(controller.view)
    //Hide
    // toggleDrawer()
}



//MARK:- Delegates.

//MARK: DrawerDelegate methods.
func addButtonClicked(sender: UIButton)
{
    //  toggleDrawer()
}   
}

抽屉视图控制器

class DrawerViewController: UIViewController
{
    //Drawer variables.
    var drawerViewHidden: Bool = false
    var addPinDrawer: AddPinDrawer!



    var viewHeight: CGFloat! = 0
    var viewWidth : CGFloat! = 0
    var shownDrawerViewY: CGFloat?
    var hiddenDrawerViewY: CGFloat?

    var addButton: UIButton?

    init(width: CGFloat, height: CGFloat)
    {
        super.init(nibName: nil, bundle: nil)

        viewWidth  = width
        viewHeight = height

        setUpUI()
    }

    override func viewDidLoad()
    {
        super.viewDidLoad()

        // Do any additional setup after loading the view.

    }

    override func viewWillAppear(animated: Bool)
    {
        super.viewWillAppear(animated)


    }

    override func didReceiveMemoryWarning()
    {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    required override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: NSBundle?)
    {
        super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
    }

    required init(coder aDecoder: NSCoder)
    {
        fatalError("init(coder:) has not been implemented")
    }


    //MARK:- UI setup
     func setUpUI()
    {
        setUpDimensions()
        setUpDrawerElements()
//        toggleDrawer()
    }

     func setUpDimensions()
    {
        //Determine the y in the case drawer is shown
        shownDrawerViewY  = viewHeight * 2.0/8.0

        //Determine the height of the drawer.
        let drawerHeight = viewHeight * 6.0/8.0

        //Determine the y in the case drawer is hidden
        hiddenDrawerViewY = viewHeight * 7.4/8.0

        //Create the frame, starting with the drawer shown.
        let frame = CGRectMake(0, shownDrawerViewY!, viewWidth, drawerHeight)
        //Create a new Drawer View.
        self.view = UIView(frame: frame)

        setUpAddButton(frame)



        //Setup the background image of the drawer.
        self.view.backgroundColor = UIColor(patternImage: UIImage(named: Constants.drawerBackgroundImage)!)
    }

    func setUpDrawerElements()
    {
        //Setup the button.
        setUpAddPinDrawer()
    }

    func setUpAddPinDrawer()
    {
        addPinDrawer = AddPinDrawer(frame: CGRectMake(0, 0, self.view.frame.width, self.view.frame.height))
//        self.view.addSubview(addPinDrawer)
    }



    //MARK: Handling drawer toggles
    func toggleDrawer()
    {
        //Toggle the variable.
        drawerViewHidden = !drawerViewHidden

        //If the drawer must be hidden.
        if drawerViewHidden
        {
            hideDrawer()
        }

        //If the drawer must be shown
        else
        {
            showDrawer()
        }
    }

    func hideDrawer()
    {
        //Hide the drawer
        UIView.animateWithDuration(0.6, animations: { () -> Void in
            self.view.frame.origin.y = self.hiddenDrawerViewY!
        })
      //  drawerView.hideDrawer()
    }

    func showDrawer()
    {
        UIView.animateWithDuration(0.6, animations: { () -> Void in
            self.view.frame.origin.y = self.shownDrawerViewY!
        })
      //  drawerView.showDrawer()
    }


    func setUpAddButton(frame: CGRect!)
    {
        //Determine the button dimensions.
        let width:CGFloat = 75.0//1.0/10.0 * viewHeight
        let x = frame.width/2.0 - width/2.0

        //Button background image.
        let background = UIImage(named: Constants.addButtonBackgroundImage)!

        //Create the button.
        addButton = UIButton(frame: CGRectMake(x, -width/2.0, width, width)) as UIButton
//        addButton!.setImage(background, forState: UIControlState.Normal)

        addButton?.backgroundColor = UIColor.yellowColor()

        //Add the event handler.
        addButton!.addTarget(self, action: "buttonAdd:", forControlEvents: .TouchUpInside)


        //Set it rotated.
//        self.addButton!.transform = CGAffineTransformMakeRotation(CGFloat(M_PI_4))


        //Add the button to the subview.
        self.view.addSubview(addButton!)

//        println(addButton!.targetForAction("test", withSender: addButton)!)
    }

    func buttonAdd(sender: UIButton)
    {
        println("Helloooo asdf")
    }
}

Answer 1

我已经解决了这个问题。 DrawerViewController 的初始化有一个很小的错误，在主视图控制器中，我正在创建一个名为 DrawerViewController 的变量并初始化它的视图。一旦方法完成，这个变量将被释放，这意味着所有事件都不会被处理。由于没有处理按钮事件的方法，导致应用崩溃。

解决办法：

将 DrawerViewController 设为实例变量并在主视图控制器中对其进行初始化。