具有动态高度的UICollectionView不会在单元格之间获得相同的空间 [英] UICollectionView with dynamic height not getting same space between cell

问题描述

我遇到类似问题中发现了这个问题还有。

解决方案

我已经得到了解决这类问题的一般解决方案：

   - （void）viewDidLoad 
 {
 [super viewDidLoad]; 
 
 [cView registerNib：[UINib nibWithNibName：@CViewCellbundle：nil] forCellWithReuseIdentifier：kCellID]; 
 
 CViewFlowLayout * fl = [[CViewFlowLayout alloc] init]; 
 fl.minimumInteritemSpacing = 10; 
 fl.scrollDirection = UICollectionViewScrollDirectionVertical; 
 self.cView.collectionViewLayout = fl; 
 
 NSString * strJson =返回JSON STRING的我的功能; 
 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]; //这个函数生成高度并将其保存到字典
} 
 [cView reloadData]; 
  

}

然后，更新代码在CViewFlowLayout.m中，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 * attributesToReturn中的属性）
 {
 if（nil == attributes.representedElementKind）
 {
 NSIndexPath * indexPath = attributes.indexPath; 
 attributes.frame = [self layoutAttributesForItemAtIndexPath：indexPath] .frame; 
} 
} 
返回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; 
返回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; 
返回currentItemAttributes; 
} 
  

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

I am having similar problem like this

I am generating height of view at run time.Here is my code

@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;
}

I had tried above link solution but it is not working for me. Here is an image of my output.

I need the spacing to be same. Is anyone having solution for this issue ?

Is this bug of UICOllectionView ? Because I found this issue in this article also.

解决方案

I've got the general solution for this kind of problem:

- (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];

}

Then, update the code in CViewFlowLayout.m, which is a subclass of UICollectionViewFlowLayout.

Here is the code:

#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;
}

This solution will work for vertical scrolling only. If you want to display more or less columns, just change the numColumns.

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