相关疑难解决方法(0)

我有两个部分UICollectionView.我想UICollectionView仅显示第1节中的节标题.不在第0部分.

于是,我就回nil以viewForSupplementaryElementOfKind:方法section == 0并返回查看的section == 1.

它崩溃并显示以下错误:

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

这是补充视图的代码.

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
    UICollectionReusableView *sectionHeader = nil;
    if (kind == UICollectionElementKindSectionHeader && indexPath.section == 1) {
        sectionHeader = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"EventSectionHeader" forIndexPath:indexPath];
        sectionHeader.layer.borderWidth = .5f;
        sectionHeader.layer.borderColor = [UIColor colorWithRed:221.0 / 255.0 green:223.0 / 255.0 blue:220.0 / 255.0 alpha:1.0].CGColor;
    }

    return sectionHeader;
}

我发现在viewForSupplementaryElementOfKind:方法崩溃时也会返回nil .其他答案建议删除该方法.

但我想只显示特定部分的节标题.如何只为一个部分实现返回视图？谢谢.任何帮助,将不胜感激.

编辑:

正如@san所说,我已更新代码以隐藏节标题.有用.它隐藏了标题.但我仍然看到节标题处的空白空间.预期结果是如果隐藏了节标题,则应该没有空格. …

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 = …