自定义UICollectionViewLayout不同单元尺寸

Question

我想自定义UICollectionViewLayout这样。 http://i.stack.imgur.com/aWUIa.jpg

当我滚动第二页图像大小不符合单元格大小; http://i.stack.imgur.com/GOUmF.jpg

然后再转回第一页;
http://i.stack.imgur.com/lQQ3h.png

图像尺寸和单元尺寸不适合彼此。 这里我的自定义布局代码;

// 
// SeyahatLayout.m 
// SeyahatTrend 
// 
// Created by Mehmet Can Yavuz on 03.06.2013. 
// Copyright (c) 2013 Mehmet Can Yavuz. All rights reserved. 
// 

#import "SeyahatLayout.h" 
#import "SeyahatLayoutAttributes.h" 

#define kNumberOfItemsPerPage 5 

static NSString * const BHPhotoAlbumLayoutPhotoCellKind = @"PhotoCell"; 

@interface SeyahatLayout() 

@property (nonatomic, strong) NSDictionary *layoutInfo; 

@end 

@implementation SeyahatLayout 

- (CGSize)collectionViewContentSize 
{ 
    // Ask the data source how many items there are (assume a single section) 
    id<UICollectionViewDataSource> dataSource = self.collectionView.dataSource; 
    int numberOfItems = [dataSource collectionView:self.collectionView 
          numberOfItemsInSection:0]; 

    // Determine how many pages are needed 
    int numberOfPages = ceil((float)numberOfItems/(float)kNumberOfItemsPerPage); 

    // Set the size 
    float pageWidth = self.collectionView.frame.size.width; 
    float pageHeight = self.collectionView.frame.size.height; 
    CGSize contentSize = CGSizeMake(numberOfPages * pageWidth, pageHeight); 

    return contentSize; 
} 

#pragma mark - Layout 

- (void)prepareLayout 
{ 
    NSMutableDictionary *newLayoutInfo = [NSMutableDictionary dictionary]; 
    NSMutableDictionary *cellLayoutInfo = [NSMutableDictionary dictionary]; 

    NSInteger sectionCount = [self.collectionView numberOfSections]; 
    NSIndexPath *indexPath = [NSIndexPath indexPathForItem:0 inSection:0]; 

    for (NSInteger section = 0; section < sectionCount; section++) { 
     NSInteger itemCount = 
      [self.collectionView numberOfItemsInSection:section]; 

     for (NSInteger item = 0; item < itemCount; item++) { 
      indexPath = [NSIndexPath indexPathForItem:item inSection:section]; 

      SeyahatLayoutAttributes* attr = 
       [self layoutAttributesForItemAtIndex:item]; 
     // UICollectionViewLayoutAttributes *itemAttributes = 
     // [UICollectionViewLayoutAttributes 
     //  layoutAttributesForCellWithIndexPath:indexPath]; 
     // itemAttributes.frame = [self frameForAlbumPhotoAtIndexPath:indexPath]; 

      [cellLayoutInfo setObject:attr forKey:indexPath]; 
     } 
    } 

    newLayoutInfo[BHPhotoAlbumLayoutPhotoCellKind] = cellLayoutInfo; 
    self.layoutInfo = newLayoutInfo; 
} 

- (UICollectionViewLayoutAttributes *)layoutAttributesForItemAtIndexPath: 
     (NSIndexPath *)indexPath { 

    return self.layoutInfo[BHPhotoAlbumLayoutPhotoCellKind][indexPath]; 
} 

-(NSArray*)layoutAttributesForElementsInRect:(CGRect)rect 
{ 
// NSInteger itemCount = [self.collectionView numberOfItemsInSection:0]; 
// NSMutableArray* attributes = [NSMutableArray array]; 
// for (NSInteger i=0 ; i < itemCount; i++) { 
//  NSIndexPath* indexPath = [NSIndexPath indexPathForItem:i 
                 inSection:0]; 
//  [attributes addObject: 
      [self layoutAttributesForItemAtIndexPath:indexPath]]; 
// } 
// return attributes; 
    NSLog(@"RECTX: %f",rect.origin.x); 
    NSLog(@"RECTY: %f",rect.origin.y); 
    NSLog(@"RECTWIDTH: %f",rect.size.width); 
    NSLog(@"RECTHEIGHT: %f",rect.size.height); 

    id<UICollectionViewDataSource> dataSource = self.collectionView.dataSource; 
    int numberOfItems = [dataSource collectionView:self.collectionView 
          numberOfItemsInSection:0]; 

    NSMutableArray* attributes = [NSMutableArray array]; 
    int page = rect.origin.x/1024.0; 
    if(numberOfItems>0){ 
    for(NSInteger i = 0; i<kNumberOfItemsPerPage; i++){ 
     int x = page*kNumberOfItemsPerPage + i; 
     NSLog(@"%d",x); 
     NSIndexPath* indexPath = [NSIndexPath indexPathForItem:x inSection:0]; 
     [attributes addObject:self.layoutInfo[BHPhotoAlbumLayoutPhotoCellKind] 
      [indexPath]]; 
    } 

    return attributes; 
    } 
    else 
     return nil; 

} 

- (SeyahatLayoutAttributes *)layoutAttributesForItemAtIndex:(int)index 
{ 
    NSIndexPath *path = [NSIndexPath indexPathForItem:index inSection:0]; 
    SeyahatLayoutAttributes *attributes = 
     (SeyahatLayoutAttributes *)[UICollectionViewLayoutAttributes 
            layoutAttributesForCellWithIndexPath:path]; 

    // Figure out what page this item is on 
    int pageNumber = floor((float)index/(float) kNumberOfItemsPerPage); 

    // Set the horizontal offset for the start of the page 
    float pageWidth = self.collectionView.frame.size.width; 
    float horizontalOffset = pageNumber * pageWidth; 

    // Now, determine which position this cell occupies on the page. 
    int indexOnPage = index % kNumberOfItemsPerPage; 

    int column = 0; 
    switch (indexOnPage) { 
     case 0: 
     case 1: 
      column = 0; 
      break; 
     case 2: 
     case 3: 
     case 4: 
      column = 3; 
      break; 
     default: 
      column = 0; 
      break; 
    } 

    int row = 0; 
    switch (indexOnPage) { 
     case 0: 
     case 2: 
      row = 0; 
      break; 
     case 3: 
      row = 1; 
      break; 
     case 1: 
     case 4: 
      row = 2; 
      break; 
     default: 
      row = 0; 
      break; 
    } 

    horizontalOffset = horizontalOffset + ((175.0 + 30.0) * column) + 30.0; 
    float verticalOffset = (194.0 + 30.0) * row + 30.0; 

    // finally, determine the size of the cell. 
    float width = 0.0; 
    float height = 0.0; 

    switch (indexOnPage) { 
     case 0: 
      width = 585.0; 
      height = 418.0; 
      break; 
     case 1: 
      width = 585.0; 
      height = 194.0; 
      break; 
     default: 
      width = 350.0; 
      height = 194.0; 
      break; 
    } 

    CGRect frame = CGRectMake(horizontalOffset, verticalOffset, width, height); 
    [attributes setFrame:frame]; 

    return attributes; 
} 

+ (Class)layoutAttributesClass 
{ 
    return [SeyahatLayoutAttributes class]; 
} 

@end 

这里是我自定义的uicollectionviewcell代码;

// 
// SeyahatCell.m 
// SeyahatTrend 
// 
// Created by Mehmet Can Yavuz on 03.06.2013. 
// Copyright (c) 2013 Mehmet Can Yavuz. All rights reserved. 
// 

#import "SeyahatCell.h" 
#import "PNCollectionCellBackgroundView.h" 
@implementation SeyahatCell 

- (id)initWithFrame:(CGRect)frame 
{ 
    self = [super initWithFrame:frame]; 
    if (self) { 
     // Initialization code 
     //self.backgroundColor = [UIColor whiteColor]; 


     PNCollectionCellBackgroundView* backgroundView = 
      [[PNCollectionCellBackgroundView alloc] initWithFrame:frame]; 
     self.backgroundView = backgroundView; 
     self.imageView = 
      [[UIImageView alloc] initWithFrame:CGRectMake(5, 
                 5, 
                 frame.size.width-10, 
                 frame.size.height-10)]; 
     [self.contentView addSubview:self.imageView]; 
    } 
    return self; 
} 

和我的cellForItemAtIndexPath方法;

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

    SeyahatCell *seyahatCell = 
    [collectionView dequeueReusableCellWithReuseIdentifier:SeyahatCellIdentifier  
               forIndexPath:indexPath]; 


    Post * p = [self.posts objectAtIndex:indexPath.row]; 
    [seyahatCell.imageView setImage:nil]; 
    if(p.thumbnail){ 
     [seyahatCell.imageView setImageWithURL:[NSURL URLWithString:p.thumbnail]]; 
    } 
    else{ 
     [seyahatCell.imageView setImage:nil]; 
    } 

    return seyahatCell; 
} 

我该如何解决这个问题？

Answer 1

尝试使用现有的解决方案布局。为此，我更愿意使用https://github.com/bryceredd/RFQuiltLayout