UICollectionView和Supplementary View崩溃

Question

我有一个UICollectioView工作正常.有两种方法可以访问此页面.

1. 虽然应用程序.
2. 点按推送通知.

除了一个案例,一切都很好.

如果用户在聊天中,然后他退出应用程序(主页按钮),那么他会得到推送通知,他按下它并且应用程序崩溃.

崩溃:

2015-09-25 10:28:15.140 Quest [298:16922] *断言失败 - [UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:],/ BuildRoot/Library/Cache/com.apple.xbs/Sources/UIKit/UIKit-3505.16/UICollectionView.m:1519 2015-09-25 10:28:15.146任务[298:16922]* 终止应用程序由于未捕获的异常 'NSInternalInconsistencyException',理由是: 'UICollectionView数据源未设置'***第一掷调用堆栈:(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:以NSException类型的未捕获异常终止

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()

}

集合设置代码

@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
    }
}

Answer 1

如果您在集合视图中使用自定义布局,请检查其数据源是否为零:

- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect

结果应如下所示:

- (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:

• 断言失败 - [UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:]

您还可以检查以下主题,但在我的情况下它们没有解决任何问题: UICollectionView和Supplementary View(标题)

如果节标题隐藏在UICollectionView中,则删除空白空间

希望它会对你有所帮助,你不会浪费我那么多的时间.@eeeee谢谢你指点我正确的方向.