UICollectionView未正确更新 - 使用THStringyFlowLayout(UICollectionView is not updating properly - used THStringyFlowLayout)

 当我的应用程序启动时，它会从持久性中获取数据并在我的集合视图中显示5个单元格。 这些单元格看起来像普通的TableView单元格，但我使用Collection View进行后续的布局调整。 整个屏幕需要8个单元格。 
 
 之后的第二秒，使用19个单元格的数据更新模型，并通过调用以下内容更新集合视图： 
 
[self.collectionView reloadData];
 
 已经显示5个单元格的那些用新数据很好地刷新，但就是这样。 直到我触摸屏幕并向下滚动单元格的高度，才会显示其他单元格。 然后立即显示3个单元格并填充屏幕。 从那一刻起，一切都很好，但在滚动之前，它没有正确更新。 
 
 当我调试它时，我看到，在调用reloadData之后调用collectionView：numberOfItemsInSection：它返回正确的数字19，但是只询问那些5个单元格的collectionView：cellForItemAtIndexPath：（直到我滚动）。 
 
 有点绝望，谢谢你的帮助。 
 
 编辑 - 添加源代码： 
 
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 1;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return [self.manager.jubilees count];
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    DLog(@"asked for cell: %i", indexPath.row); //just for debugging to know, what is going on
    JUJubileeCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"JubileeCell"
                                                                forIndexPath:indexPath];
    cell.jubilee = self.manager.jubilees[(NSUInteger) indexPath.row];
    return cell;
}

// called when model is updated
-(void)jubileesUpdated {
    DLog(@"jubileesUpdated");
    [self.collectionView reloadData];
}
 
 编辑2：当加载前5个单元格时，[self.collectionView contentSize]为（width = 320，height = 358）。 当加载所有19个单元格并调用reloadData时，contentSize为（width = 320，height = 1366） - 但实际上并未显示单元格:(。 
 
 编辑3：问题是由使用THStringyFlowLayout引起的 - 如果我找到原因，我会发布更多内容。 

When my app starts, it takes data from the persistence and displays 5 cells in my Collection View. These cells looks like normal TableView cells, but I use Collection View for later layout tweaks. It takes 8 cells to fill whole screen.
 
A second after that, the model is updated with the data for 19 cells and the Collection View is updated by calling:
 
[self.collectionView reloadData];
 
Those already displayed 5 cells are nicely refreshed with new data, but that's it. The other cells are not displayed until I touch the screen and scroll down about the height of the cell. Then instantly 3 cells are displayed and fills the screen. From that moment, everything is fine, but until I scroll, it is not updated correctly.
 
When I debugged it, I see, that the collectionView:numberOfItemsInSection: is called after calling reloadData and it returns correct number 19, but the collectionView:cellForItemAtIndexPath: is asked just for those 5 cells (until I scroll).
 
Kind of desperate here, thanks for your help.
 
Edit - added source code:
 
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 1;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return [self.manager.jubilees count];
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    DLog(@"asked for cell: %i", indexPath.row); //just for debugging to know, what is going on
    JUJubileeCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"JubileeCell"
                                                                forIndexPath:indexPath];
    cell.jubilee = self.manager.jubilees[(NSUInteger) indexPath.row];
    return cell;
}

// called when model is updated
-(void)jubileesUpdated {
    DLog(@"jubileesUpdated");
    [self.collectionView reloadData];
}
 
edit 2: When first 5 cells are loaded, the [self.collectionView contentSize] is (width=320, height=358). When the all 19 cells are loaded and reloadData called, contentSize is (width=320, height=1366) - but cells are not actually displayed :(.
 
edit 3: The problem is caused by using THStringyFlowLayout - I will post more, if I find the reason.

原文：https://stackoverflow.com/questions/22335503