ios - setRightBarButtonItems 不起作用

Question

我想在 UINavigationBar 的右侧设置 2 个按钮。下面是源代码。没有错误，但也没有按钮。它是一个 UIViewController，而不是一个 UINavigationViewController

let buttonEdit: UIButton = UIButton.buttonWithType(UIButtonType.Custom) as! UIButton
buttonEdit.frame = CGRectMake(0, 0, 40, 40)
buttonEdit.setImage(UIImage(named:"me44.png"), forState: UIControlState.Normal)
buttonEdit.addTarget(self, action: "rightNavItemEditClick:", forControlEvents: UIControlEvents.TouchUpInside)
var rightBarButtonItemEdit: UIBarButtonItem = UIBarButtonItem(customView: buttonEdit)

let buttonDelete: UIButton = UIButton.buttonWithType(UIButtonType.Custom) as! UIButton
buttonDelete.frame = CGRectMake(0, 0, 40, 40)
buttonDelete.setImage(UIImage(named:"me44.png"), forState: UIControlState.Normal)
buttonDelete.addTarget(self, action: "rightNavItemDeleteClick:", forControlEvents: UIControlEvents.TouchUpInside)

var rightBarButtonItemDelete: UIBarButtonItem = UIBarButtonItem(customView: buttonDelete)

// add multiple right bar button items       
self.navigationController?.navigationItem.setRightBarButtonItems([rightBarButtonItemDelete, rightBarButtonItemEdit] as [AnyObject], animated: true)

//I also tried code below no luck either
self.navigationItem.setRightBarButtonItems([rightBarButtonItemDelete, rightBarButtonItemEdit] as [AnyObject], animated: true)

Answer 1

这段代码是错误的:

self.navigationController?.navigationItem.setRightBarButtonItems(
    [rightBarButtonItemDelete, rightBarButtonItemEdit] as [AnyObject], animated: true)

您没有设置导航 Controller 的navigationItem；您设置您的 navigationItem。此外，[AnyObject] 是不必要的。所以:

self.navigationItem.setRightBarButtonItems(
    [rightBarButtonItemDelete, rightBarButtonItemEdit], animated: true)

但是，请注意，只有当您的 View Controller 是 UINavigationController 的子级时，它才有效。设置 View Controller 的 navigationItem 只会在那种情况下自动填充导航栏。如果您不处于那种情况——即，如果您的界面中只有一个“松散”的导航栏——您需要手动填充导航栏(通过设置 < em>它的 navigationItem).

(另外，请注意，如果您没有"me44.png" 图像，则可能是您的代码正在运行，但您只是看不到任何东西。 )