ios - UICollectionView 不添加单元格

Question

我有一个包含 UICollectionView 的 UITableViewCell。每个 Collection View 最多可以有 3 个单元格。我正在使用此代码添加单元格。

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
    return 1;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    collectionIndex++;
    return [[collectionCellData objectAtIndex:collectionIndex] count];
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    NSLog(@"collection Cell: %@", indexPath);
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"availableTimeCell" forIndexPath:indexPath];
    NSLog(@"Data: %@", [collectionCellData objectAtIndex:collectionIndex]);

    UILabel *label = [[UILabel alloc] initWithFrame:cell.frame];
    [label setFont:[UIFont fontWithName:@"Avenir Next" size:13.0]];
    [label setTextColor:[UIColor colorWithRed:0.108 green:0.550 blue:1.000 alpha:1.000]];
    NSDateFormatter *dateFormatter = [NSDateFormatter new];
    [dateFormatter setDateFormat:@"yyyy-MM-dd HH:mm:ss"];
    NSString *startTimeString = [[[collectionCellData objectAtIndex:collectionIndex] objectAtIndex:indexPath.row] valueForKey:@"startTimestamp"];
    NSLog(@"Start Time String: %@", startTimeString);
    NSDate *date = [dateFormatter dateFromString:startTimeString];
    NSLog(@"New Date: %@", date);
    [dateFormatter setDateFormat:@"h:mm a"];

    NSString *newDate = [dateFormatter stringFromDate:date];
    NSLog(@"NEW NEW Date: %@", newDate);
    label.text = newDate;
    [cell addSubview:label];
    return cell;
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return CGSizeMake(53, 17);
}

我的 cellForRowAtIndexPath 是

- (UITableViewCell *)tableCeption:(BJTableCeption *)tableCeption cellForItem:(id)item
{
    NSArray *topLevelObjects;
    EngagementListCell *cell;
    if ([item isKindOfClass:[BJItemObject class]]) {

        cell = (EngagementListCell *)[tableCeption dequeueReusableCellWithIdentifier:@"EngagementListCell"];

        if (cell == nil) {
            topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"EngagementListCells" owner:nil options:nil];
            cell = [topLevelObjects objectAtIndex:0];
        }
        cell.lblStaff.text = [((AppointmentGrid *)((BJItemObject *)item).item).employeeObject valueForKey:@"displayName"]; // Staff name
        cell.availableTimeCollection.dataSource = self;
        cell.availableTimeCollection.delegate = self;
        [cell.availableTimeCollection registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"availableTimeCell"];

        [collectionCellData addObject:[NSMutableArray arrayWithArray:[((AppointmentGrid *)((BJItemObject *)item).item) slots]]];
        NSLog(@"cell data: %@", collectionCellData);
        [cell.availableTimeCollection reloadData];


    } else {
        cell = (EngagementListCell *)[tableCeption dequeueReusableCellWithIdentifier:@"ServiceHeaderCell"];

        if (cell == nil) {
            topLevelObjects = [[NSBundle mainBundle] loadNibNamed:@"EngagementListCells" owner:nil options:nil];
            cell = [topLevelObjects objectAtIndex:1];
        }
        cell.lblService.text = ((BJCategoryObject *)item).item; // Service name
    }

    return cell;
}

日志输出

2014-01-28 08:39:42.818 Customer View[30896:70b] Start Time String: 2014-01-30 08:00:00
2014-01-28 08:39:42.819 Customer View[30896:70b] New Date: 2014-01-30 15:00:00 +0000
2014-01-28 08:39:42.819 Customer View[30896:70b] NEW NEW Date: 8:00 AM
2014-01-28 08:39:42.819 Customer View[30896:70b] collection Cell: <NSIndexPath: 0x9099470> {length = 2, path = 0 - 0}
2014-01-28 08:39:42.820 Customer View[30896:70b] Data: (
        {
        endTimestamp = "2014-01-30 08:05:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:00:00";
    }
)
2014-01-28 08:39:42.820 Customer View[30896:70b] Start Time String: 2014-01-30 08:00:00
2014-01-28 08:39:42.821 Customer View[30896:70b] New Date: 2014-01-30 15:00:00 +0000
2014-01-28 08:39:42.821 Customer View[30896:70b] NEW NEW Date: 8:00 AM
2014-01-28 08:39:42.821 Customer View[30896:70b] collection Cell: <NSIndexPath: 0x90a3130> {length = 2, path = 0 - 0}
2014-01-28 08:39:42.822 Customer View[30896:70b] Data: (
        {
        endTimestamp = "2014-01-30 08:05:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:00:00";
    },
        {
        endTimestamp = "2014-01-30 08:10:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:05:00";
    },
        {
        endTimestamp = "2014-01-30 08:15:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:10:00";
    }
)
2014-01-28 08:39:42.822 Customer View[30896:70b] Start Time String: 2014-01-30 08:00:00
2014-01-28 08:39:42.822 Customer View[30896:70b] New Date: 2014-01-30 15:00:00 +0000
2014-01-28 08:39:42.823 Customer View[30896:70b] NEW NEW Date: 8:00 AM
2014-01-28 08:39:42.823 Customer View[30896:70b] collection Cell: <NSIndexPath: 0x90d7eb0> {length = 2, path = 0 - 1}
2014-01-28 08:39:42.823 Customer View[30896:70b] Data: (
        {
        endTimestamp = "2014-01-30 08:05:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:00:00";
    },
        {
        endTimestamp = "2014-01-30 08:10:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:05:00";
    },
        {
        endTimestamp = "2014-01-30 08:15:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:10:00";
    }
)
2014-01-28 08:39:42.823 Customer View[30896:70b] Start Time String: 2014-01-30 08:05:00
2014-01-28 08:39:42.824 Customer View[30896:70b] New Date: 2014-01-30 15:05:00 +0000
2014-01-28 08:39:42.824 Customer View[30896:70b] NEW NEW Date: 8:05 AM
2014-01-28 08:39:42.824 Customer View[30896:70b] collection Cell: <NSIndexPath: 0x9091980> {length = 2, path = 0 - 2}
2014-01-28 08:39:42.825 Customer View[30896:70b] Data: (
        {
        endTimestamp = "2014-01-30 08:05:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:00:00";
    },
        {
        endTimestamp = "2014-01-30 08:10:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:05:00";
    },
        {
        endTimestamp = "2014-01-30 08:15:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:10:00";
    }
)
2014-01-28 08:39:42.825 Customer View[30896:70b] Start Time String: 2014-01-30 08:10:00
2014-01-28 08:39:42.826 Customer View[30896:70b] New Date: 2014-01-30 15:10:00 +0000
2014-01-28 08:39:42.826 Customer View[30896:70b] NEW NEW Date: 8:10 AM
2014-01-28 08:39:42.826 Customer View[30896:70b] collection Cell: <NSIndexPath: 0x906ddc0> {length = 2, path = 0 - 0}
2014-01-28 08:39:42.827 Customer View[30896:70b] Data: (
        {
        endTimestamp = "2014-01-30 08:05:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:00:00";
    },
        {
        endTimestamp = "2014-01-30 08:10:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:05:00";
    },
        {
        endTimestamp = "2014-01-30 08:15:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:10:00";
    }
)
2014-01-28 08:39:42.827 Customer View[30896:70b] Start Time String: 2014-01-30 08:00:00
2014-01-28 08:39:42.827 Customer View[30896:70b] New Date: 2014-01-30 15:00:00 +0000
2014-01-28 08:39:42.828 Customer View[30896:70b] NEW NEW Date: 8:00 AM
2014-01-28 08:39:42.828 Customer View[30896:70b] collection Cell: <NSIndexPath: 0x906dde0> {length = 2, path = 0 - 1}
2014-01-28 08:39:42.828 Customer View[30896:70b] Data: (
        {
        endTimestamp = "2014-01-30 08:05:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:00:00";
    },
        {
        endTimestamp = "2014-01-30 08:10:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:05:00";
    },
        {
        endTimestamp = "2014-01-30 08:15:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:10:00";
    }
)
2014-01-28 08:39:42.828 Customer View[30896:70b] Start Time String: 2014-01-30 08:05:00
2014-01-28 08:39:42.829 Customer View[30896:70b] New Date: 2014-01-30 15:05:00 +0000
2014-01-28 08:39:42.829 Customer View[30896:70b] NEW NEW Date: 8:05 AM
2014-01-28 08:39:42.829 Customer View[30896:70b] collection Cell: <NSIndexPath: 0x906de70> {length = 2, path = 0 - 2}
2014-01-28 08:39:42.830 Customer View[30896:70b] Data: (
        {
        endTimestamp = "2014-01-30 08:05:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:00:00";
    },
        {
        endTimestamp = "2014-01-30 08:10:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:05:00";
    },
        {
        endTimestamp = "2014-01-30 08:15:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:10:00";
    }
)
2014-01-28 08:39:42.830 Customer View[30896:70b] Start Time String: 2014-01-30 08:10:00
2014-01-28 08:39:42.831 Customer View[30896:70b] New Date: 2014-01-30 15:10:00 +0000
2014-01-28 08:39:42.831 Customer View[30896:70b] NEW NEW Date: 8:10 AM
2014-01-28 08:39:42.831 Customer View[30896:70b] collection Cell: <NSIndexPath: 0x90677c0> {length = 2, path = 0 - 0}
2014-01-28 08:39:42.832 Customer View[30896:70b] Data: (
        {
        endTimestamp = "2014-01-30 08:05:00";
        slotDuration = 5;
        startTimestamp = "2014-01-30 08:00:00";
    }
)
2014-01-28 08:39:42.832 Customer View[30896:70b] Start Time String: 2014-01-30 08:00:00
2014-01-28 08:39:42.832 Customer View[30896:70b] New Date: 2014-01-30 15:00:00 +0000
2014-01-28 08:39:42.833 Customer View[30896:70b] NEW NEW Date: 8:00 AM

截图:

应该是这样的

我的问题是，即使 numberOfItemsInSection 有时会返回 3，它也只会显示所有时间为上午 8:00 的第一个单元格。

在为 Collection View 填充单元格时，我这样做是正确的还是我做错了什么？

Answer 1

我看到了一些潜在的问题:

首先，它看起来像 collectionView:numberOfItemsInSection: 期望总是从 0...N 部分开始顺序调用，但事实并非如此，因此您的迭代器变量 collectionIndex 可能无法按预期工作。

其次，看起来您正在为 TableView 委托(delegate)方法中的 Collection View (collectionCellData) 填充数据模型。如果 BJTableCeption 像 UITableView 一样工作，这也可能会导致问题，因为 cellForItem: 会被多次调用，导致 中有额外的对象collectionCellData.

第三，在您的集合单元格出列之后，每次都会将标签添加到单元格中。因此，如果一个收集单元被重复使用，它将有重复的标签堆叠在一起。您应该创建一个自定义子类，仅在初始化时创建其 subview 。

我建议在重新加载集合单元之前填充一次 collectionCellData 数组(viewDidLoad 或 initWithNibName:bundle: 是放置的好地方您的设置代码)。在 cellForItem: 中，为每个 Collection View 的 tag 属性分配包含它的行；然后，在 collectionView:numberOfItemsInSection: 中使用标签代替 collectionIndex。