カスタムを作成UICollectionViewLayoutし、ストーリーボードの Collection View Controller に配置しました。アイテム/セルの表示にそれほど問題はありませんでした。私の問題は、viewForSupplementaryElementOfKindが呼び出されていないことです。その理由を特定することはできないようです。デフォルトのレイアウトに戻そうとしましたが、それを呼び出しますが、カスタムが必要UICollectionViewLayoutです。NSLog確認するために s を残しましたviewForSupplementaryElementOfKindが、呼び出されていません。
ここに私の MyCollectionViewController.m があります
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view.
viewArray = [NSMutableArray array];
//setup the delegate for vertical flow layout
[(VerticalFlowLayout*)self.collectionViewLayout setDelegate:self];
//register the headers
[self.collectionView registerNib:[ButtonHeaderCollectionReusableView nib] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:[ButtonHeaderCollectionReusableView reusableID]];
//set the insets
[self.collectionView setContentInset:UIEdgeInsetsMake(23, 5, 10, 5)];
}
#pragma mark - CollectionView DataSource
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return [self.cardsArray count];
}
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
NSLog(@"Number of Sections");
return 1;
}
- (UICollectionViewCell*)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"Making Card");
CardCell *card = [collectionView dequeueReusableCellWithReuseIdentifier:@"CardCell" forIndexPath:indexPath];
// UILabel *cardLabel = [card viewWithTag:101];
// [cardLabel setText:[textArray objectAtIndex:[indexPath row]]];
return card;
}
- (UICollectionReusableView*)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {
NSLog(@"Making Header");
UICollectionReusableView *reusableView = nil; /*[[UICollectionReusableView alloc] initWithFrame:CGRectMake(0, 0, 100, 75)];*/
// [reusableView setBackgroundColor:[UIColor blackColor]];
if (kind == UICollectionElementKindSectionHeader) {
ButtonHeaderCollectionReusableView *headerview = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:[ButtonHeaderCollectionReusableView reusableID] forIndexPath:indexPath];
return headerview;
}
// if (kind == UICollectionElementKindSectionFooter) {
// UICollectionReusableView *footerview = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"FooterView" forIndexPath:indexPath];
// }
return reusableView;
}
- (CGSize)collectionView:collectionView layout:(nonnull UICollectionViewLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
return CGSizeMake(180.0f, 72.0f);
}
ここに私の MyFlowLayout.m があります
- (id)initWithCoder:(NSCoder *)aDecoder {
NSLog(@"Vertical Flow Layout init with coder");
if(self = [super initWithCoder:aDecoder]) {
contentHeight = 0;
cachedAttributes = [NSMutableArray array];
}
return self;
}
- (void)prepareLayout {
NSLog(@"Preparing Layout");
// [super prepareLayout];
contentWidth = CGRectGetWidth(self.collectionView.bounds) - (self.collectionView.contentInset.left + self.collectionView.contentInset.right);
if([cachedAttributes count] == 0) {
//compute for column width
CGFloat columnWidth = contentWidth / NUMBER_OF_COLUMNS;
NSMutableArray *xOffsets = [NSMutableArray array];
for(int i = 0; i < NUMBER_OF_COLUMNS; i++) {
[xOffsets addObject:[NSNumber numberWithFloat:(i * columnWidth)]];
}
//compute for height
NSMutableArray *yOffsets = [NSMutableArray array];
for(int i = 0; i < NUMBER_OF_COLUMNS; i++) {
[yOffsets addObject:[NSNumber numberWithFloat:75]];
}
int column = 0;
//loop through all the sections and items in the collectionview
for(int i = 0; i < self.collectionView.numberOfSections; i++) {
for(int j = 0; j < [self.collectionView numberOfItemsInSection:i]; j++) {
NSIndexPath *indexPath = [NSIndexPath indexPathForItem:j inSection:i];
//time to do some frame calculation
///let's start with the width
CGFloat width = columnWidth - CELL_PADDING * 2;
///then the height
CGFloat viewHeight = [self.delegate getViewHeightWithCollectionView:self.collectionView indexPath:indexPath withWidth:width];
CGFloat height = CELL_PADDING + viewHeight + /*textHeight +*/ CELL_PADDING;
CGFloat xOffset = [[xOffsets objectAtIndex:column] floatValue];
CGFloat yOffset = [[yOffsets objectAtIndex:column] floatValue];
CGRect frame = CGRectMake(xOffset, yOffset, columnWidth, height);
CGRect insetFrame = CGRectInset(frame, CELL_PADDING, CELL_PADDING);
//now that computation is done we shall make the attributes
UICollectionViewLayoutAttributes *attributes = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
[attributes setFrame:insetFrame];
[cachedAttributes addObject:attributes];
//time to increment the height and the column
contentHeight = MAX(contentHeight, CGRectGetMaxY(frame));
NSNumber *yOffSetColumn = [yOffsets objectAtIndex:column];
yOffSetColumn = [NSNumber numberWithFloat:([yOffSetColumn floatValue] + height)];
[yOffsets replaceObjectAtIndex:column withObject:yOffSetColumn];
NSLog(@"Content Height: %f yOffSetColumn: %@ == %@", contentHeight, yOffSetColumn, [yOffsets objectAtIndex:column]);
column = column >= (NUMBER_OF_COLUMNS - 1) ? 0 : ++column;
}
}
}
}
- (CGSize)collectionViewContentSize {
// NSLog(@"Collection View Content Size");
return CGSizeMake(contentWidth, contentHeight + 75);
}
// called after preparelayout to determine which items are visible in the given rect
- (NSArray<UICollectionViewLayoutAttributes *> *)layoutAttributesForElementsInRect:(CGRect)rect {
NSMutableArray<UICollectionViewLayoutAttributes *> *layoutAttributes = [NSMutableArray array];
NSInteger sectionsCount = [self.collectionView.dataSource numberOfSectionsInCollectionView:self.collectionView];
NSLog(@"Sections count: %ld", (long)sectionsCount);
for(int i = 0; i < sectionsCount; i++) {
//for header
UICollectionViewLayoutAttributes *headerAttributes = [self layoutAttributesForSupplementaryViewOfKind:UICollectionElementKindSectionHeader atIndexPath:[NSIndexPath indexPathForItem:0 inSection:i]];
// if(CGRectIntersectsRect(headerAttributes.frame, rect)) {
// NSLog(@"Adding Section Attribute");
[layoutAttributes addObject:headerAttributes];
// }
for (UICollectionViewLayoutAttributes *attributes in cachedAttributes) {
if(CGRectIntersectsRect(attributes.frame, rect)) {
[layoutAttributes addObject:attributes];
}
}
// NSInteger itemsCount = [self.collectionView numberOfItemsInSection:i];
// for(int j = 0; j < itemsCount; j++) {
// UICollectionViewLayoutAttributes *attributes = [self layoutAttributesForItemAtIndexPath:[NSIndexPath indexPathForItem:j inSection:i]];
// if(CGRectIntersectsRect(attributes.frame, rect)) {
// [layoutAttributes addObject:attributes];
// }
// }
}
return layoutAttributes;
}
//- (UICollectionViewLayoutAttributes*)layoutAttributesForItemAtIndexPath:(NSIndexPath *)indexPath {
// NSLog(@"Layout Attributes For Item: %ld %ld", [indexPath row], [indexPath section]);
//
// UICollectionViewLayoutAttributes *attributes = [cachedAttributes objectAtIndex:[indexPath row]];
// return attributes;
//}
- (UICollectionViewLayoutAttributes *)layoutAttributesForSupplementaryViewOfKind:(NSString *)elementKind atIndexPath:(NSIndexPath *)indexPath {
NSLog(@"Layout Attributes For Header: %@ %ld %ld", elementKind, [indexPath row], [indexPath section]);
UICollectionViewLayoutAttributes *attributes = [UICollectionViewLayoutAttributes layoutAttributesForCellWithIndexPath:indexPath];
[attributes setFrame:CGRectMake(0, 0, contentWidth /*320*/, 75.0f)];
return attributes;
}
MyFlowLayout でわかるように、私が試したことがいくつかありますが、それでも呼び出されませんでしたviewForSupplementaryElementOfKind。layoutAttributesForItemAtIndexPath持っているので実装してみlayoutAttributesForSupplementaryViewOfKindました。ヘッダーが生成されるかどうかを確認するためだけに表示される 75 や 320 などの固定番号も使用してみました。ご覧のデリゲートは、ビューの高さを取得するためのものです。
ヘッダーに表示される十分なスペースを与えて、NSLogs を全体に残しましたが、まだ(UICollectionReusableView*)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath呼び出されていません。
ここに私が見て試したもののいくつかがあります：stackoverflowですが、私が含めたコメント付きのコードからわかるように。それでもうまくいきませんでした。
助けてくれてありがとう。