iOS collectionView XIB 非XIB 随笔

XIB

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    self.collectionView.dataSource = self;
    self.collectionView.delegate = self;
    [self.collectionView registerNib:[UINib nibWithNibName:@"ZFHomeAdvertCell" bundle:nil] forCellWithReuseIdentifier:@"ZFHomeAdvertCell"];

    UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc]init];
    flowLayout.minimumLineSpacing = 0;
    flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;
    flowLayout.itemSize = CGSizeMake(400, 60);
    self.collectionView.collectionViewLayout = flowLayout;
}

#pragma mark--UICollectionViewDelegate,UICollectionViewDataSource

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

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

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    ZFHomeAdvertCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"ZFHomeAdvertCell" forIndexPath:indexPath];
    cell.backgroundColor = [UIColor redColor];
    return cell;
}

非XIB

#pragma mark - Lazy Loads

- (UICollectionView *)collectionView {
    if (!_collectionView) {
        UICollectionViewFlowLayout * layout = [[UICollectionViewFlowLayout alloc]init];
        //水平方向间距
        layout.minimumInteritemSpacing = 10;
        //垂直方向间距
        layout.minimumLineSpacing = 10;
        //垂直方向
        layout.scrollDirection = UICollectionViewScrollDirectionVertical;
//        水平方向
//        layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
        //设置内边距
        layout.sectionInset = UIEdgeInsetsMake(20,20,20,20);
        layout.itemSize = CGSizeMake((Screen_Width-40-20)/3, 80);
        _collectionView = [[UICollectionView alloc]initWithFrame:CGRectZero collectionViewLayout:layout];
        _collectionView.showsHorizontalScrollIndicator = NO;
        _collectionView.showsVerticalScrollIndicator = NO;
        _collectionView.delegate = self;
        _collectionView.dataSource  = self;
        _collectionView.backgroundColor = [UIColor whiteColor];
        _collectionView.scrollEnabled = YES;
        [ _collectionView registerClass:[UserCardCollectCell class] forCellWithReuseIdentifier:@"UserCardCollectCell"];
    }
    return _collectionView;
}

#pragma mark - UICollectionViewDataSource

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
    return self.circleCategoryModel.data.count ? self.circleCategoryModel.data.count:0;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    NSString *Identifier = [NSString stringWithFormat:@"CircleCategoryLabelCollectCell"];
    CircleCategoryLabelCollectCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:Identifier forIndexPath:indexPath];
    return cell;
}

#pragma mark - UICollectionViewDelegate

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{

}

设置每个cell的大小

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
}