我有一个工作正常的 UICollectioView。 有 2 种方法可以到达此页面。

1. 通过应用。
2. 点击推送通知。

除一种情况外，一切正常。

如果用户正在聊天，然后他退出应用程序(主页按钮) 然后他收到推送通知，他按下它，应用程序崩溃了。

崩溃:

2015-09-25 10:28:15.140 Quest[298:16922] * Assertion failure in -[UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:], /BuildRoot/Library/Caches/com.apple.xbs/Sources/UIKit/UIKit-3505.16/UICollectionView.m:1519 2015-09-25 10:28:15.146 Quest[298:16922] * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UICollectionView dataSource is not set' *** First throw call stack: (0x1828b4f5c 0x1973b7f80 0x1828b4e2c 0x1837a3f3c 0x187f97a38 0x187e6ebd4 0x187e6fb54 0x187e69b88 0x187e0700c 0x18760df14 0x187608b20 0x1876089e0 0x18760807c 0x187607dd0 0x1880c0bd4 0x18286c48c 0x18286bdc4 0x182869d4c 0x182798dc0 0x18d8ec088 0x187e72f60 0x100215590 0x197be28b8) libc++abi.dylib: terminating with uncaught exception of type NSException

推送处理程序中的代码:

func application(application: UIApplication, didReceiveRemoteNotification userInfo: [NSObject : AnyObject]) {

                let home = storyboard.instantiateViewControllerWithIdentifier("home") as! HomeViewController
                let chat = storyboard.instantiateViewControllerWithIdentifier("chat") as! ChatViewController

                var controllers : [UIViewController] = [login, chat]
                NotificationManager.handleNotification(userInfo, controllers: &controllers, storyboard: storyboard)
                navC.viewControllers = controllers
                self.window?.makeKeyAndVisible()

}

collectionview设置代码

@IBOutlet weak var chatCollectionView: UICollectionView! {
    didSet {
        chatCollectionView.registerNib(UINib(nibName: "ChatTimeStampCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "ChatTimeStampCell")
        chatCollectionView.registerNib(UINib(nibName: "ChatReceiverCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "ChatReceiverCell")
        chatCollectionView.registerNib(UINib(nibName: "ChatSenderCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: "ChatSenderCell")
        chatCollectionView.registerNib(UINib(nibName: "ChatHeaderCollectionReusableView", bundle: nil), forSupplementaryViewOfKind: UICollectionElementKindSectionHeader, withReuseIdentifier: "ChatHeaderCell")

        chatCollectionView.dataSource = self
        chatCollectionView.delegate = self
    }
}

最佳答案

如果您在 Collection View 中使用自定义布局，请检查其数据源是否为 nil:

- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect

结果应该是这样的:

- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect
    if (self.collectionView.dataSource != nil) {
        // Your layout code    
        return array;
    }
    return nil;
}

此更改解决了以下问题:

• Assertion failure in -[UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:]

您还可以查看以下主题，但它们并没有解决我的问题: UICollectionView and Supplementary View (header)

Removing empty space, if the section header is hidden in the UICollectionView

希望它能帮到你，你不会像我一样浪费时间。 @eeeee 谢谢你给我指明了正确的方向。

关于ios - UICollectionView 和补充 View 崩溃，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32777059/