Question

我尝试使用自定义nib创建UICollectionView。为此，我做了与UITableView相同的事情：

MyCollectionViewController.m

- (void)viewDidLoad
{
    [super viewDidLoad];

    myCollectionView.delegate = self;
    myCollectionView.dataSource = self;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
MyCollectionCell *cell = [MyCollectionCell newCellOrReuse:collectionView atIndexPath:indexPath];

    return cell;
}

MyCollectionCell.m

+ (MyCollectionCell *)newCell
{
    UIViewController *vc = [[UIViewController alloc] initWithNibName:@"MyCollectionCell" bundle:nil];
    MyCollectionCell *cell = (MyCollectionCell *)vc.view;
    [cell initCell];
    return cell;
}

+ (MyCollectionCell *)reuse:(UICollectionView *)collectionView atIndexPath:(NSIndexPath *)indexPath
{
    NSString *rid = @"MyCollectionCell";
    return (MyCollectionCell *)[collectionView dequeueReusableCellWithReuseIdentifier:rid forIndexPath:indexPath];
}

+ (MyCollectionCell *)newCellOrReuse:(UICollectionView *)collectionView atIndexPath:(NSIndexPath *)indexPath
{
    MyCollectionCell *cell = [MyCollectionCell reuse:collectionView atIndexPath:indexPath];
    if (!cell) cell = [MyCollectionCell newCell];
    return cell;
}

- (void) initCell
{
}

我收到错误

*** Assertion failure in -[UICollectionView _dequeueReusableViewOfKind:withIdentifier:forIndexPath:], /SourceCache/UIKit/UIKit-2380.17/UICollectionView.m:2249

在这一行

return (MyCollectionCell *)[collectionView dequeueReusableCellWithReuseIdentifier:rid forIndexPath:indexPath];

我真的不知道发生了什么。它与重用有关，因为如果我只调用[MyCollectionCell newCell];它就可以了。实际上它仅适用于iOS6。在iOS7上，我得到*** Assertion failure in -[UICollectionView _createPreparedCellForItemAtIndexPath:withLayoutAttributes:applyAttributes:], /SourceCache/UIKit_Sim/UIKit-2903.23/UICollectionView.m:1367

感谢您的帮助！

Answer 1

- (void)viewDidLoad {
    [super viewDidLoad];

    myCollectionView.delegate = self;
    myCollectionView.dataSource = self;

    [collectionView registerNib:[UINib nibWithNibName:@"MyCollectionCell" bundle:nil] forCellWithReuseIdentifier:@"MyCollectionCell"];
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    NSString *rid = @"MyCollectionCell";
    return (MyCollectionCell *)[collectionView dequeueReusableCellWithReuseIdentifier:rid forIndexPath:indexPath];
}

然后在MyCollectionCell.m中取消所有类方法并从awakeFromNib调用initCell。即：

-(void)awakeFromNib {
    [super awakeFromNib];
    [self initCell];
}

尝试创建UICollectionViewCell时断言失败

1 个答案: