objective-c - pushViewController 失败

Question

我正在尝试做一个“项目列表”->“项目详细信息”类型的应用程序。到目前为止，我已经成功地完成了列表部分。我还为项目详细信息创建了一个新 View ，但是当我单击要查看详细信息的项目时出现错误。

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{    
    ItemDetailsView *detailViewController = [[ItemDetailsView alloc] initWithNibName:@"DetailView" bundle:[NSBundle mainBundle]];

    // ERROR HERE
    [self.navigationController pushViewController:detailViewController animated:YES];
    [detailViewController release]; 
}

到目前为止，新 View 只有一个空标签，上面写着“View Changed: OK”。没有别的。

ItemDetailsView 是继承自 UIViewController 的 View 。

为了创建这个 View ，我去了 New File -> Cocoa Touch -> UIViewController 子类。

当我尝试执行下面的行时，我得到的错误是一个“signabrt”//ERROR HERE

完整消息如下:

2011-10-02 17:26:03.582 Teste Data Nav[10035:b303] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Could not load NIB in bundle: 'NSBundle </Users/leo/Library/Application Support/iPhone Simulator/4.3.2/Applications/FA60D1E7-1B98-4943-98AA-C86A2339AC3E/Teste Data Nav.app> (loaded)' with name 'DetailView''
*** Call stack at first throw:
(
    0   CoreFoundation                      0x00dc25a9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x00f16313 objc_exception_throw + 44
    2   CoreFoundation                      0x00d7aef8 +[NSException raise:format:arguments:] + 136
    3   CoreFoundation                      0x00d7ae6a +[NSException raise:format:] + 58
    4   UIKit                               0x0020f0fa -[UINib instantiateWithOwner:options:] + 2024
    5   UIKit                               0x00210ab7 -[NSBundle(UINSBundleAdditions) loadNibNamed:owner:options:] + 168
    6   UIKit                               0x000c6628 -[UIViewController _loadViewFromNibNamed:bundle:] + 70
    7   UIKit                               0x000c4134 -[UIViewController loadView] + 120
    8   UIKit                               0x000c400e -[UIViewController view] + 56
    9   UIKit                               0x000c2482 -[UIViewController contentScrollView] + 42
    10  UIKit                               0x000d2f25 -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:] + 48
    11  UIKit                               0x000d1555 -[UINavigationController _layoutViewController:] + 43
    12  UIKit                               0x000d27aa -[UINavigationController _startTransition:fromViewController:toViewController:] + 326
    13  UIKit                               0x000cd32a -[UINavigationController _startDeferredTransitionIfNeeded] + 266
    14  UIKit                               0x000d4562 -[UINavigationController pushViewController:transition:forceImmediate:] + 932
    15  UIKit                               0x000cd1c4 -[UINavigationController pushViewController:animated:] + 62
    16  Teste Data Nav                      0x00002d4c -[RootViewController tableView:didSelectRowAtIndexPath:] + 220
    17  UIKit                               0x0008bb68 -[UITableView _selectRowAtIndexPath:animated:scrollPosition:notifyDelegate:] + 1140
    18  UIKit                               0x00081b05 -[UITableView _userSelectRowAtPendingSelectionIndexPath:] + 219
    19  Foundation                          0x0079b79e __NSFireDelayedPerform + 441
    20  CoreFoundation                      0x00da38c3 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 19
    21  CoreFoundation                      0x00da4e74 __CFRunLoopDoTimer + 1220
    22  CoreFoundation                      0x00d012c9 __CFRunLoopRun + 1817
    23  CoreFoundation                      0x00d00840 CFRunLoopRunSpecific + 208
    24  CoreFoundation                      0x00d00761 CFRunLoopRunInMode + 97
    25  GraphicsServices                    0x00ffa1c4 GSEventRunModal + 217
    26  GraphicsServices                    0x00ffa289 GSEventRun + 115
    27  UIKit                               0x00022c93 UIApplicationMain + 1160
    28  Teste Data Nav                      0x000023b9 main + 121
    29  Teste Data Nav                      0x00002335 start + 53
)
terminate called throwing an exceptionCurrent language:  auto; currently objective-c

Answer 1

基本上，它找不到名为“DetailView”的 .xib 文件。确保您的 initWithNibName: 具有用于 .xib 文件的正确字符串名称。

该错误的重要部分是:

Could not load NIB in bundle: 'NSBundle </.../Teste Data Nav.app> (loaded)' with name 'DetailView'

这意味着您的包中没有名为 DetailView 的 .xib 文件。确保使用正确的文件名:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{    
    ItemDetailsView *detailViewController = [[ItemDetailsView alloc] initWithNibName:@"ItemDetailsView" bundle:nil];

    // ERROR HERE
    [self.navigationController pushViewController:detailViewController animated:YES];
    [detailViewController release]; 
}

---

编辑(从评论)将 View 连接到 File's Owner，如下所示:

---

确保 self 有一个 navigationController 父级。如果这是应用程序启动时出现的主视图，则需要将 UINavigationController 添加到 MainWindow.xib 并将其 rootViewController 设置为具有此表的 View Controller 。

您可以通过以下方式进行测试:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{    
    NSLog("self.navController view controllers: %@", [[[self navigationController] viewControllers] description]);
    // Or something like this:
    if (self.parentViewController == self.navigationController) {
        NSLog(@"I have a nav controller dad!");
    } else {
        NSLog(@"I have no nav controller!");
    }
    // ItemDetailsView *detailViewController = [[ItemDetailsView alloc] initWithNibName:@"DetailView" bundle:[NSBundle mainBundle]];
    // ERROR HERE
    // [self.navigationController pushViewController:detailViewController animated:YES];
    // [detailViewController release]; 
}

如果 NSLog 打印出一个 View Controller 数组，那么还有另一个问题，但是如果它在 NSLog 上抛出一个错误或者它打印出一个空数组，那么你的 self 没有 navigationController 父级。