UICollectionViewLayout子类

Question

我已经在情节提要中创建了一个自定义，并将其类型更改为UICollectionView，并选择了我的UICollectionViewLayout子类作为它的类。

在UICollectionViewLayout子类中有以下代码。但当我运行应用程序时，我在集合视图中根本看不到任何东西。我错过了什么？

@implementation CollectionViewLayout

- (id)initWithCoder:(NSCoder*)aDecoder
{
    if(self = [super initWithCoder:aDecoder]) {
        // Do something
        NSLog(@"init with coder");

        self.collectionView.backgroundColor = [UIColor redColor];

        self = [super init];

        self.imageArray = [NSMutableArray array];
        for(int i = 0; i <32; i++)
        {
            NSString *imageToLoad = [NSString stringWithFormat:@"%d.JPG", i];
            UIImage *image = [UIImage imageNamed:imageToLoad];
            [self.imageArray addObject:image];
        }

        longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(longPressGestureRecognized:)];
        longPress.delegate = self;
        [self.collectionView addGestureRecognizer:longPress];

        UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapGesture:)];
        tapGesture.numberOfTapsRequired = 2;
        [self.collectionView addGestureRecognizer:tapGesture];

        self.collectionView.delegate = self;
        self.collectionView.dataSource = self;
    }
    return self;
}

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

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath;
{

    NSLog(@"cell for item");

    Cell *cell = [cv dequeueReusableCellWithReuseIdentifier:kCellID forIndexPath:indexPath];
    [[cell viewWithTag:999] removeFromSuperview];
    self.isDeleteActive = NO;
    cell.image.image = [self.imageArray objectAtIndex:indexPath.row];
    return cell;
}

Answer 1

 - (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section;
 - (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath

这些方法来自不应在自定义布局类中实现的“UICollectionViewDataSource”。