UICollectionViewFlowLayout * flowLayout = [[UICollectionViewFlowLayout alloc]init];

       

滚动方向:

 

flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal ;

   

行间距(最小)

  

flowLayout.minimumLineSpacing = 0;

  

列间距(最小)

    flowLayout.minimumInteritemSpacing = 30;  

item大小

    flowLayout.itemSize = CGSizeMake(40, 30);   

setcion 的边距

    flowLayout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10);   

header 大小

    flowLayout.headerReferenceSize = CGSizeMake(320, 20);   

footer大小

    flowLayout.footerReferenceSize = CGSizeMake(320, 20);

重用标志

static NSString *  cellidentifier = @"cell";

注册重用标识符

    [cView registerClass:[MyCollectionViewCell class] forCellWithReuseIdentifier:cellidentifier];

Cell 重用

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

{     MyCollectionViewCell * cell  = [collectionView dequeueReusableCellWithReuseIdentifier:cellidentifier forIndexPath:indexPath];    cell.backgroundColor = [UIColor redColor];    cell.textLavel.text = [NSString stringWithFormat:@"%ld",(long)indexPath.row];        return cell;}