UICollectionViewController的使用

重写init方法,创建布局参数- (id)init

{

[[UICollectionViewFlowLayout alloc] init];// 2.每个cell的尺寸

layout.itemSize = CGSizeMake(100, 100);
return [super initWithCollectionViewLayout:layout];

} 

注册cell(告诉collectionView将来创建怎样的cell)
[self.collectionView registerClass:[UICollectionViewCell class]

forCellWithReuseIdentifier:@"product"]; 

2. 从缓存池中取出cell

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

{

UICollectionViewCell *cell = [collectionView
dequeueReusableCellWithReuseIdentifier:@"product"
forIndexPath:indexPath];

return cell;
}

• UICollectionViewFlowLayout称为”流水布局”,用来约束cell的显示

• 常见属性
➢ Cell的尺寸
@property (nonatomic) CGSize itemSize;

➢ cell之间的水平间距
@property (nonatomic) CGFloat minimumInteritemSpacing;

➢ cell之间的垂直间距
@property (nonatomic) CGFloat minimumLineSpacing;

➢ 四周的内边距
@property (nonatomic) UIEdgeInsets sectionInset;