Peek＆amp; Pop - Pop在UICollectionView

Question

我有一个嵌入在UINavigationController中的UITableViewController，我试图实现Peek＆amp; amp;弹出TableView。我有＆＃34;偷看＆＃34;部分工作完美，但当我尝试＆＃34; pop＆＃34;进入下一个ViewController，我是一个单元格＆＃34;偷看＆＃34;并显示下一个单元格。我是＆＃34;弹出＆＃34;进入UICollectionView，正如我所提到的，＆＃34; peek＆＃34;一半表示正确的单元格，但是＆＃34; pop＆＃34;才不是。只有在我使用[self.navigationController showViewController:viewControllerToCommit sender:nil];或[self.navigationController pushViewController:viewControllerToCommit animated:YES];执行＆＃34; pop＆＃34;时才会出现此问题。

这是＆＃34; Peek＆＃34;显示正确的细胞

＆＃34; Pop＆＃34;显示错误的单元格

我尝试使用[self presentViewController:viewControllerToCommit animated:YES completion:nil];并显示正确的单元格，但这并没有给出我需要的导航元素，所以我无法使用它（除非有办法让所有的导航元素回来了。）

我最初的想法是，我的应用程序如何计算CollectionViewCell的大小有问题。这是我正在使用的代码，虽然看起来它可以正常使用Peek＆amp;流行。

-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
    CGSize collectionViewBounds = collectionView.bounds.size;

    int navigationHeight = self.navigationController.navigationBar.bounds.size.height;
    int toolbarHeight = self.navigationController.toolbar.bounds.size.height;
    int statusBarHeight = [UIApplication sharedApplication].statusBarFrame.size.height;

    int cellHeight = collectionViewBounds.height - (navigationHeight + statusBarHeight + toolbarHeight);
    int cellWidth = collectionViewBounds.width;

    return CGSizeMake(cellWidth, cellHeight);
}

为了增加我的困惑，＆＃34; pop＆＃34;当TableView中的第一个或最后一个项目被“偷看”时，它可以完美地工作。对此的任何帮助将不胜感激。

Answer 1

So I finally figured out what was causing this problem. My app is a Universal app, and I use a Popover Segue on iPads. In viewWillAppearof my ViewController that is "popping" incorrectly, I use [self setPreferredContentSize:CGSizeMake(400.0, 600.0)] to determine the size of the Popover on an iPad. Once I removed that line, my Peek & Pop worked perfectly.

I ended up adding a new property to my ViewController @property BOOL fromPeek and set that property to YES in - (UIViewController *)previewingContext:(id <UIViewControllerPreviewing>)previewingContext viewControllerForLocation:(CGPoint)location of my previewing ViewController. Finally, I modified my viewWillAppear to be if(!fromPeek) [self setPreferredContentSize:CGSizeMake(400.0, 600.0)]; and the problem is now solved!