Question

在我的应用中，只有2个观看次数。第一个视图是一个集合视图，当您点击图像时，它会转到MWPhotoBrowser以查看其完整大小的图像。

我正在通过互联网检索约100张图片并将其添加到NSMutableArray。这有问题。当我第一次运行应用并从网格中选择缩略图时，它会显示最后一张图像。不是我选择的那个。请注意，我第一次强调，因为它只在第一次发生。如果我返回并点按其他图像，则会正确显示所选图像。下面是假设如何工作的屏幕截图。

enter image description here

这是代码

#import "UIImageView+WebCache.h"
#import "ViewController.h"
#import "MWPhotoBrowser.h"
#import "Image.h"
#import "ImageCell.h"

@interface ViewController () <UICollectionViewDelegate, UICollectionViewDataSource, MWPhotoBrowserDelegate>

@property (strong, nonatomic) NSMutableArray *images;
@property (strong, nonatomic) NSMutableArray *browserImages;
@property (strong, nonatomic) MWPhotoBrowser *browser;

@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.browser = [[MWPhotoBrowser alloc] initWithDelegate:self];
    self.browser.displayActionButton = YES;
    self.browser.displayNavArrows = YES;
    self.browser.displaySelectionButtons = NO;
    self.browser.zoomPhotosToFill = YES;
    self.browser.alwaysShowControls = YES;
    self.browser.enableGrid = NO;
    self.browser.startOnGrid = NO;
    self.browser.wantsFullScreenLayout = NO;

    [self.browser showNextPhotoAnimated:YES];
    [self.browser showPreviousPhotoAnimated:YES];

    [self loadImages];
}

- (void)loadImages
{
    self.images = [[NSMutableArray alloc] init];
    self.browserImages = [[NSMutableArray alloc] init];

    NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"%@%@", HOST_URL, @"All_Images.php"]];
    NSData *jsonResults = [NSData dataWithContentsOfURL:url];
    NSDictionary *results = [NSJSONSerialization JSONObjectWithData:jsonResults options:0 error:NULL];

    NSDictionary *images = results[@"Images"];
    for (NSDictionary *img in images) {
        Image *imageObj = [[Image alloc] init];
        imageObj.imageId = [img objectForKey:@"id"];
        imageObj.imageName = [img objectForKey:@"name"];

        // Get the full image path
        NSString *fullImagePath = [NSString stringWithFormat:@"%@%@", HOST_URL, [img objectForKey:@"full_image"]];
        imageObj.imagePath = fullImagePath;

        // Get the thumbnail image path depending on the device
        NSString *thumbnailPath;
        if (DEVICE_IS_PAD) {
            thumbnailPath = [NSString stringWithFormat:@"%@%@", HOST_URL, [img objectForKey:@"thumbnail_ipad"]];
        } else {
            thumbnailPath = [NSString stringWithFormat:@"%@%@", HOST_URL, [img objectForKey:@"thumbnail_iphone"]];
        }
        imageObj.imageThumbnail = thumbnailPath;

        // Creates an object for each image and fill it with the retrieved info
        [self.images addObject:imageObj];

        // This array stores the image paths for later use (displaying them in a photo browser)
        MWPhoto *browserImage = [MWPhoto photoWithURL:[NSURL URLWithString:imageObj.imagePath]];
        browserImage.caption = imageObj.imageName;
        [self.browserImages addObject:browserImage];
    }
    [self.collectionView reloadData];
}

#pragma mark - MWPhotoBrowserDelegate
- (NSUInteger)numberOfPhotosInPhotoBrowser:(MWPhotoBrowser *)photoBrowser
{
    return self.browserImages.count;
}

- (id <MWPhoto>)photoBrowser:(MWPhotoBrowser *)photoBrowser photoAtIndex:(NSUInteger)index
{
    if (index < self.browserImages.count) {
        return self.browserImages[index];
    }
    return nil;
}

#pragma mark - UICollectionViewDataSource
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return self.images.count;
}

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
    return 1;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"ImageCell";
    ImageCell *cell = (ImageCell *)[collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];

    Image *image = self.images[indexPath.row];
    [cell.imageView setImageWithURL:[NSURL URLWithString:image.imageThumbnail] placeholderImage:[UIImage imageNamed:@"placeholder"]];

    return cell;
}

#pragma mark - UICollectionViewDelegate
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    // Opens the image browser
    [self.browser setCurrentPhotoIndex:indexPath.row];
    [self.navigationController pushViewController:self.browser animated:YES];
}

@end

我无法找到为什么它在我第一次选择图像时显示网格的最后一个图像。我已经上传了一个包含该问题的演示项目，因此您可以更轻松地快速查看它。 https://www.dropbox.com/s/tp6a67f83l0rzin/PhotoBrowserTest.zip

我非常感谢任何人帮助纠正这个问题。

谢谢。

Answer 1

在项目中更改这些方法

- (NSUInteger)numberOfPhotos {
   if (_photoCount == NSNotFound || _photoCount == 0) {
       if ([_delegate respondsToSelector:@selector(numberOfPhotosInPhotoBrowser:)]) {
           _photoCount = [_delegate numberOfPhotosInPhotoBrowser:self];
       } else if (_depreciatedPhotoData) {
        _photoCount = _depreciatedPhotoData.count;
       }
   }
   if (_photoCount == NSNotFound) _photoCount = 0;
   return _photoCount;
}

AND

- (id)initWithDelegate:(id <MWPhotoBrowserDelegate>)delegate {
    if ((self = [self init])) {
        _delegate = delegate;
        [self setCurrentPhotoIndex:0];
    }
    return self;
}

你需要检查你的_photoCount == 0，因为你第一次没有这个信息而_photoCount将是0，但第二次你的numberOfPhotosInPhotoBrowser将是正确的

从集合视图中选择时，MWPhotoBrowser未显示正确的图像

1 个答案: