CollectionView with JSON Data

Question

我发送json并将值存储在Collection视图中，数组在didSelectItemAtIndexPath显示为空请帮助我..

    NSDictionary * jsonResult = [NSJSONSerialization JSONObjectWithData:responseData options:kNilOptions error:nil];

    albumImageArr = [NSMutableArray array];
    [albumImageArr addObjectsFromArray:[jsonResult objectForKey:@"photoList"]];

    NSLog(@"Array %@",albumImageArr);

    for (NSDictionary *dic in albumImageArr)
    {

    str1=[dic objectForKey:@"photoURL"];
    [arr addObject:str1];

    }


- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView1 cellForItemAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *identifier = @"Cell";

    CustomCell *cell = (CustomCell *)[collectionView1 dequeueReusableCellWithReuseIdentifier:identifier forIndexPath:indexPath];

    NSString *path = [[albumImageArr objectAtIndex:indexPath.row] objectForKey:@"photoURL"];
    NSURL *url = [NSURL URLWithString:path];
    NSData *data = [NSData dataWithContentsOfURL:url];
    UIImage *image = [[UIImage alloc] initWithData:data];

    cell.imageView.image = image;

    return cell;
}


- (void)collectionView:(UICollectionView *)collectionView1 didSelectItemAtIndexPath:(NSIndexPath *)indexPath {

    UIStoryboard *storyBoard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];

    PhotoDescriptionViewController *albumsController = (PhotoDescriptionViewController *)[storyBoard instantiateViewControllerWithIdentifier:@"DescriptionView"];

    NSString *senderImg=[arr objectAtIndex:indexPath.item];
    albumsController.receivedImage=senderImg;

    [self.navigationController pushViewController:albumsController animated:YES];

}

Answer 1

您只需要执行类似于您在cellForRowAtIndexPath中所做的操作，然后将albumsController的receivedImage设置为图像（假设receivedImage是UIImage）。

- (void)collectionView:(UICollectionView *)collectionView1 didSelectItemAtIndexPath:(NSIndexPath *)indexPath {

    UIStoryboard *storyBoard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];

    PhotoDescriptionViewController *albumsController = (PhotoDescriptionViewController *)[storyBoard instantiateViewControllerWithIdentifier:@"DescriptionView"];

    NSString *path = [[albumImageArr objectAtIndex:indexPath.row] objectForKey:@"photoURL"];
    NSURL *url = [NSURL URLWithString:path];
    NSData *data = [NSData dataWithContentsOfURL:url];
    UIImage *image = [[UIImage alloc] initWithData:data];

    albumsController.receivedImage = image;

    [self.navigationController pushViewController:albumsController animated:YES];

}

回应您的进一步询问： 在PhotoDescriptionViewController中将receivedImage从NSString更改为UIImage，然后在viewWillAppear :(或无论您将图像设置在何处），改为：

imageView.image = receivedImage;