uicollectionview旋转单元可见性及位置和顺序

Question

我有一个UICollectionView应该具有3列和5行。 它们是静态的，不会更改。 UICollectionView不应滚动，因此单元UICollectionView可见。 在纵向模式下看起来不错，但是在横向模式下视图变得混乱。 如何以有意义的方式对细胞进行重新排序？ 还是可以拉伸内容以使所有单元格都可见？

肖像 ：

风景 ：

- (void)viewDidLoad
{
    [super viewDidLoad];

    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
    layout.scrollDirection = UICollectionViewScrollDirectionVertical;

    UICollectionView *collec = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 160, 320, 280) collectionViewLayout:layout];
    [collec registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"test"];
    collec.backgroundColor = [UIColor yellowColor];
    collec.delegate = self;
    collec.dataSource = self;
    collec.scrollEnabled = NO;
    collec.translatesAutoresizingMaskIntoConstraints = NO;
    [self.view addSubview:collec];

    NSDictionary *headerViewDic = @{@"collec" : collec};
    NSArray *constraintsHeaderView = [NSLayoutConstraint constraintsWithVisualFormat:@"|[collec]|" options:0 metrics:nil views:headerViewDic];
    NSArray *constraintsHeaderViewV = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-160-[collec]-8-|" options:0 metrics:nil views:headerViewDic];
    [self.view addConstraints:constraintsHeaderView];
    [self.view addConstraints:constraintsHeaderViewV];

    [collec setContentHuggingPriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisHorizontal | UILayoutConstraintAxisVertical ];
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return 3;
}

-(NSInteger) numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
    return 5;
}

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

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

    CGSize mElementSize = CGSizeMake(97, 50);
    return mElementSize;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
{
    return 0;
}

- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section
{
    return 0;
}
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
    return UIEdgeInsetsMake(0,7,7,7);  // top, left, bottom, right
}

Answer 1

尝试查找设备方向，然后交换部分和行的值，以使行发生