Question

基本上，我有自定义单元格布局的UITableView。我已经按照AppCoda.com（http://www.appcoda.com/customize-table-view-cells-for-uitableview/）上的教程了解如何制作它们。

现在，我创建了一个prepareForSegue方法，当点击UITableView中的单元格时，该方法会打开一个集合视图。因为这样做我的UITableView单元格是空白的，没有我分配给他们的信息。此外，UITableView中的所有单元格都显示相同的数据。

如何在这两者之间建立连接，使其处于完美状态，集合中的第一张图片将用作表格单元格中的样本图像，并且所有表格单元格都有单独的数据？

FolderTableViewController.m

@implementation FoldersTableViewController
{
    NSArray *folders;

    }
    @synthesize tableView;    

    - (void)viewDidLoad {
    [super viewDidLoad];

    Folder *folder1 = [Folder new];
    folder1.name = @"Barcelona";
    folder1.date = @"01/12/2014";
    folder1.imageFile = @"city23.gif";

    Folder *folder2 = [Folder new];
    folder2.name = @"Florence";
    folder2.date = @"02/12/2014";
    folder2.imageFile = @"city24.gif";

    Folder *folder3 = [Folder new];
    folder3.name = @"Berlin";
    folder3.date = @"03/12/2014";
    folder3.imageFile = @"city25.gif";

    Folder *folder4 = [Folder new];
    folder4.name = @"Swansea";
    folder4.date = @"04/12/2014";
    folder4.imageFile = @"city26.gif";

    Folder *folder5 = [Folder new];
    folder5.name = @"Cardiff";
    folder5.date = @"05/12/2014";
    folder5.imageFile = @"city29.gif";

    Folder *folder6 = [Folder new];
    folder6.name = @"Pisa";
    folder6.date = @"06/12/2014";
    folder6.imageFile = @"city30.gif";

    Folder *folder7 = [Folder new];
    folder7.name = @"Lisbon";
    folder7.date = @"07/12/2014";
    folder7.imageFile = @"city31.gif";

    Folder *folder8 = [Folder new];
    folder8.name = @"Liverpool";
    folder8.date = @"08/12/2014";
    folder8.imageFile = @"city32.gif";

    Folder *folder9 = [Folder new];
    folder9.name = @"Mannheim";
    folder9.date = @"09/12/2014";
    folder9.imageFile = @"city33.gif";

    folders = [NSArray arrayWithObjects:folder1, folder2, folder3, folder4, folder5, folder6, folder7, folder8, folder9, nil];

}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    if (tableView == self.searchDisplayController.searchResultsTableView) {
        return [searchResults count];
    } else {
        return [folders count];

    }
    // Return the number of rows in the section.
    return [folders count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{

    static NSString *foldersIdentifier = @"FolderCell";

    FolderCellTableViewCell *cell = (FolderCellTableViewCell *) [tableView dequeueReusableCellWithIdentifier:foldersIdentifier];

    if (cell == nil)
    {
        NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"FolderCell" owner:self options:nil];
        cell = [nib objectAtIndex:0];

    }

    Folder *folder = [folders objectAtIndex:indexPath.row];
    cell.nameLabel.text = folder.name;
    cell.thumbnailImageView.image = [UIImage imageNamed:folder.imageFile];
    cell.datumLabel.text = folder.date;

    return cell;
}

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
if([segue.identifier isEqualToString:@"showFolderCollection"]) {
    NSIndexPath *indexPath = [self.tableView indexPathForSelectedRow];}
}

FolderCollectionViewController.h

@property (strong, nonatomic) NSArray *photoImages;

FolderCollectionViewController.m

@synthesize photoImages;

static NSString * const reuseIdentifier = @"Cell";

- (void)viewDidLoad {
[super viewDidLoad];

self.photoImages = [NSArray arrayWithObjects:@"city23.gif", @"city24.gif", @"city25.gif", @"city26.gif", @"city29.gif", nil];

Folder.h：

@property (nonatomic, strong) NSString *name;
@property (nonatomic, strong) NSString *date;
@property (nonatomic, strong) NSString *imageFile;

Folder.m：

@synthesize name;
@synthesize date;
@synthesize imageFile;

我的自定义表格单元格：

⎮⌈UI⌉姓名⎮

⎮⌊图像⌋日期⎮

这是我的表格单元格的粗略轮廓。我无法发布图片。

对于任何不准确和错误的解释提前道歉，我刚开始学习如何编程，因此我几乎不了解它。

Answer 1

首先，我怀疑是因为你的TableView不允许选择。因此，[tableView indexPathForSelectedRow]可能会返回nil。检查以确保它返回您所期望的。如果它仍然没有，删除UITableViewCell中的segue并从FolderTableViewController创建一个 - ＆gt; FolderCollectionViewController。然后，在UITableViewDelegate实现：

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath; {
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
    [self performSegueWithIdentifier:@"showFolderCollection" sender:indexPath];
}

其次，在阅读完您的评论之后，我就会如何设置您对segue方法的准备工作：

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    if([segue.identifier isEqualToString:@"showFolderCollection"]) {
        NSIndexPath *indexPath = [sender isKindOfClass:[NSIndexPath class] ? sender : [self.tableView indexPathForSelectedRow];
        Folder *selectedFolder = self.folders[indexPath.row];
        FolderCollectionViewController *fcvc = (FolderCollectionViewController *)segue.destinationViewController;
        [fcvc loadFolder:selectedFolder];
    }
}

请注意，在FolderCollectionViewController中prepareForSegue在viewDidLoad之后和viewWillAppear之前调用

FoldersTableViewController：用户触摸行
Apple弄清楚了点击行/ Segue应该做什么
FolderCollectionViewController：viewDidLoad
FoldersTableViewController：prepareForSegue
FolderCollectionViewController：viewWillAppear:

所以不要依赖folder在viewDidLoad方法中存在FolderCollectionViewController。

- (void)viewDidLoad {
    [super viewDidLoad];
    // don't load your data here.
}

相反，创建一个这样的方法：

-(void) loadFolder:(Folder*)folder {
    self.folder = folder;
    self.photoImages = [folder loadAllImages]; // or whatever
    [self.collectionView reloadData]; // put this here or in -viewWillAppear:
}

关于文件夹类，我将其定义如下：

@interface Folder : NSObject

+(instanceType) folderWithName:(NSString*)name date:(NSDate*)date andImagePaths:(NSArray*)imagePaths;

@property (nonatomic) NSString *name;
@property (nonatomic) NSDate *date;
@property (nonatomic) NSArray *imagePaths;
@property (nonatomic, readonly) NSString *thumbPath; // use this for the UITableView Image

@end

@implementation Folder

+(instanceType) folderWithName:(NSString*)name date:(NSDate*)date andImagePaths:(NSArray*)imagePaths; {
    Folder *folder = [Folder new];
    folder.name = name;
    folder.date = date;
    folder.imagePaths = imagePaths;
}

- (NSString*) thumbPath {
    if (self.imagePaths != nil &&
        self.imagePaths.count > 0) {
        return [self.imagePaths firstObject];
    } else {
        return nil;
    }
}

@end

如何使tableview单元格保持静态并仍可访问？

1 个答案: