Question

我遇到类似的问题like this

我在运行时生成视图高度。这是我的代码

@interface CollectionViewController ()
{
    NSMutableArray *arrMain;
}
@property(nonatomic,strong) NSMutableArray *arrMain;
@end

@implementation CollectionViewController
@synthesize arrMain,


- (void)viewDidLoad
{
    [super viewDidLoad];

    [cView registerNib:[UINib nibWithNibName:@"CViewCell" bundle:nil] forCellWithReuseIdentifier:kCellID];

    CViewFlowLayout *fl = [[CViewFlowLayout alloc] init];
    self.cView.collectionViewLayout = fl;

    NSString *strJson = MY FUNCTION WHICH RETURNS JSON STRING;
    SBJSON *parser = [[SBJSON alloc] init];

    self.arrMain = [[NSMutableArray alloc] init];
    self.arrMain = [parser objectWithString:strJson error:nil];
    for (int i=0; i<[self.arrMain count]; i++) {
        NSDictionary *dic = [self.arrMain objectAtIndex:i];
        [self setTags:[[UIView alloc] init] selDictionary:dic];  // This function generates height and save it to the dictionary
    }
    [cView reloadData];
}

- (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section;
{
    return [self.arrMain count];
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{

    NSDictionary *dic = [self.arrMain objectAtIndex:indexPath.row];
    return CGSizeMake(236,40+[[dic valueForKey:@"TAGS_HEIGHT"] intValue]);
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath;
{

    CViewCell *cell =(CViewCell *) [cv dequeueReusableCellWithReuseIdentifier:kCellID forIndexPath:indexPath];
    NSDictionary *dic = [self.arrMain objectAtIndex:indexPath.row];
    if ([cell viewWithTag:11]){
        [[cell viewWithTag:11] release];
        [[cell viewWithTag:11] removeFromSuperview];
    }
    UIView *viewTags = [[UIView alloc] init];
    [viewTags setTag:11];
    [viewTags setBackgroundColor:[UIColor lightGrayColor]];
    [self setTags:viewTags selDictionary:dic];
    [viewTags setFrame:CGRectMake(5, 10, CONTENT_WIDTH, [[dic valueForKey:@"TAGS_HEIGHT"] floatValue])];
    [cell.contentView addSubview:viewTags];

    return cell;
}

我曾尝试过上面的链接解决方案，但它对我不起作用。这是我输出的图像。

我需要间距相同。有人有解决这个问题的方法吗？

这是UICOllectionView的错误吗？因为我在this article中也发现了这个问题。

Answer 1

我已经找到了解决这类问题的一般方法：

- (void)viewDidLoad
{
    [super viewDidLoad];

    [cView registerNib:[UINib nibWithNibName:@"CViewCell" bundle:nil] forCellWithReuseIdentifier:kCellID];

    CViewFlowLayout *fl = [[CViewFlowLayout alloc] init];
    fl.minimumInteritemSpacing = 10;
    fl.scrollDirection = UICollectionViewScrollDirectionVertical;
    self.cView.collectionViewLayout = fl;

    NSString *strJson = MY FUNCTION WHICH RETURNS JSON STRING;
    SBJSON *parser = [[SBJSON alloc] init];

    self.arrMain = [[NSMutableArray alloc] init];
    self.arrMain = [parser objectWithString:strJson error:nil];
    for (int i=0; i<[self.arrMain count]; i++) {
    NSDictionary *dic = [self.arrMain objectAtIndex:i];
    [self setTags:[[UIView alloc] init] selDictionary:dic];  // This function generates height and save it to the dictionary
}
    [cView reloadData];

}

然后，更新CViewFlowLayout.m中的代码，它是UICollectionViewFlowLayout的子类。

以下是代码：

#define numColumns 3
@implementation CViewFlowLayout
@synthesize numOfColumnsToDisplay;
- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect
{
    NSArray* attributesToReturn = [super layoutAttributesForElementsInRect:rect];
    for (UICollectionViewLayoutAttributes* attributes in attributesToReturn)
    {
        if (nil == attributes.representedElementKind)
        {
            NSIndexPath* indexPath = attributes.indexPath;
            attributes.frame = [self layoutAttributesForItemAtIndexPath:indexPath].frame;
        }
    }
    return attributesToReturn;
}

- (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewLayoutAttributes* currentItemAttributes = [super layoutAttributesForItemAtIndexPath:indexPath];

    if (indexPath.item < numColumns){
        CGRect f = currentItemAttributes.frame;
        f.origin.y = 0;
        currentItemAttributes.frame = f;
        return currentItemAttributes;
    }
    NSIndexPath* ipPrev = [NSIndexPath indexPathForItem:indexPath.item-numColumns inSection:indexPath.section];
    CGRect fPrev = [self layoutAttributesForItemAtIndexPath:ipPrev].frame;
    CGFloat YPointNew = fPrev.origin.y + fPrev.size.height + 10;
    CGRect f = currentItemAttributes.frame;
    f.origin.y = YPointNew;
    currentItemAttributes.frame = f;
    return currentItemAttributes;
}

此解决方案仅适用于垂直滚动。如果您想显示更多或更少的列，只需更改numColumns。

Answer 2

试试这个：

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

    return CGSizeMake(250, 150);
}

Answer 3

您可以使用属性设置大小：

flowLayout.headerReferenceSize = CGSizeMake(0, 100);//constant height for all the items header

如果动态：

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
    if (section == albumSection) {
        return CGSizeMake(0, 100);
    }

    return CGSizeZero;
}

Answer 4

在Storyboard或xib设置值中查看此内容！ enter image description here

Answer 5

您从UICollectionViewFlowLayout继承的类必须包含方法：

- (CGSize)collectionViewContentSize
{
    return CGSizeMake(200, 200) // as per your cell size
}

- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect
{
    NSArray* attributesToReturn = [super layoutAttributesForElementsInRect:rect];
    for (UICollectionViewLayoutAttributes* attributes in attributesToReturn)
    {
        if (nil == attributes.representedElementKind)
        {
            NSIndexPath* indexPath = attributes.indexPath;
            attributes.frame = [self layoutAttributesForItemAtIndexPath:indexPath].frame;
        }
    }
    return attributesToReturn;
}

- (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewLayoutAttributes* currentItemAttributes =
    [super layoutAttributesForItemAtIndexPath:indexPath];

    if (!currentItemAttributes)
    {
        currentItemAttributes = [UICollectionViewLayoutAttributes
                                 layoutAttributesForCellWithIndexPath:indexPath];
    }
    return currentItemAttributes;
}

在您的CollectionViewController中添加

#pragma mark - Collection View Datasource

- (CGSize)collectionView:(UICollectionView *)collectionView
                  layout:(UICollectionViewLayout  *)collectionViewLayout
  sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    // Adjust cell size for orientation
    if (UIDeviceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation]))
    {
        return CGSizeMake(150, 230);
    }
    return CGSizeMake(150, 230);
}

Answer 6

使用以下方法

//夫特

func collectionView(_ collectionView: UICollectionView,
    layout collectionViewLayout: UICollectionViewLayout,
    sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize{
 return CGSizeMake(250, 150);
}

//目标C

-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
return CGSizeMake(250, 150);
}

具有动态高度的UICollectionView不会在单元格之间获得相同的空间

6 个答案: