CollectionView-基本方法

@interface ViewController ()<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>

@property (nonatomic, strong) UICollectionView *collectionView;

@end

@implementation ViewController

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

    self.view.backgroundColor = [UIColor whiteColor];

    UICollectionViewFlowLayout *flowLayout = [UICollectionViewFlowLayout new];
    flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical; //水平滾動

    _collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:flowLayout];
    _collectionView.delegate = self;
    _collectionView.dataSource = self;
    _collectionView.showsHorizontalScrollIndicator = NO;
    _collectionView.backgroundColor = [UIColor whiteColor];

    //註冊cell，通過創建的CollectionCell
    [_collectionView registerClass:[ProjectCollectionCell class] forCellWithReuseIdentifier:@"CELL"];
    [self.view addSubview:_collectionView];

}
/定義UICollectionView的個數
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{

    return 13;
}


//定義每個UICollectionView的大小
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return CGSizeMake(50,50);
}
//定義每個UICollectionView 的 margin
-(UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
    return UIEdgeInsetsMake(20, 10, 5, 5);
}

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

    ProjectCollectionCell *cell = (ProjectCollectionCell *)[collectionView dequeueReusableCellWithReuseIdentifier:@"CELL" forIndexPath:indexPath];


    return cell;
}

//UICollectionView被選中時調用的方法
-(void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{

}