UICollectionView 类似于 UITableView ，布局更灵活。
//实现三个协议：
<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
//创建 UICollectionView
- (void)createCollectionView{
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
//设置对齐方式
[layout setScrollDirection:UICollectionViewScrollDirectionHorizontal];
//cell间距
layout.minimumInteritemSpacing = 5.0f;
//cell行距
layout.minimumLineSpacing = 1.0f;
//collectionViewLunBo = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 20, 320, 200)];
//需要layout 否则崩溃：UICollectionView must be initialized with a non-nil layout parameter
collectionViewLunBo = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 20, 320, 300) collectionViewLayout:layout];
collectionViewLunBo.dataSource = self;
collectionViewLunBo.delegate = self;
collectionViewLunBo.pagingEnabled = YES;
collectionViewLunBo.backgroundColor = [UIColor yellowColor];
[self.view addSubview:collectionViewLunBo];
//注册Cell类，否则崩溃: must register a nib or a class for the identifier or connect a prototype cell in a storyboard
[collectionViewLunBo registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"MyCollectionViewCell"];
}
//required
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
//[collectionViewLunBo registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"MyCollectionViewCell"];
static NSString *cellIDa = @"MyCollectionViewCell";
collectionCell = (MyCollectionViewCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellIDa forIndexPath:indexPath];
collectionCell.backgroundColor = [UIColor blueColor];
//collectionCell.imageView.image = [UIImage imageNamed:@""];
return collectionCell;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
return 4;
}
//optional
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView{
return 1;
}
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
NSLog(@"%@",indexPath);
UICollectionViewCell * cell = (UICollectionViewCell *)[collectionView cellForItemAtIndexPath:indexPath];
cell.backgroundColor = [UIColor whiteColor];
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{
return CGSizeMake(310, 300);
}
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{
return UIEdgeInsetsMake(5, 5, 5, 5);// top left bottom right Cell边界范围
}
原文：http://my.oschina.net/liuchuanfeng/blog/404901