推UIViewController到UINavigationController（也在UITabBarController中）

Question

我得到了一個在我的AppDelegate中以編程方式創建的UITabBarController。我還創建了兩個帶有一些UIViewControllers的UINavigationController。我添加導航控制器到的UITabBarController，像這樣：

BVMapViewController *mapViewController = [[[BVMapViewController alloc] initWithNibName:@"BVMapViewController_iPhone" bundle:nil] autorelease]; 
    BVFavoritesViewController *favoritesViewController = [[[BVFavoritesViewController alloc] initWithNibName:@"BVFavoritesViewController_iPhone" bundle:nil] autorelease]; 

    UINavigationController *navigationController = [[[UINavigationController alloc] initWithRootViewController:mapViewController] autorelease]; 
    [navigationController setToolbarHidden:YES]; 
    UINavigationController *navigationControllerForFavorites = [[[UINavigationController alloc] initWithRootViewController:favoritesViewController] autorelease]; 

    self.tabBarController = [[[UITabBarController alloc] init] autorelease]; 
    NSArray* controllers = [NSArray arrayWithObjects:navigationController, navigationControllerForFavorites, nil]; 
    self.tabBarController.viewControllers = controllers; 
    [self.window setRootViewController:self.tabBarController]; 

結果工作正常創建與兩個導航控制器標籤欄控制器。

問題如下： 第一個UINavigationController包含一個帶有MKMapView的UIViewController。該地圖顯示了一堆POI，因此當您點擊其中一個POI時，該應用向web服務（在後臺）發送一個請求，該請求一旦完成，它會通知視圖控制器將另一個UIViewController推入導航堆棧顯示關於POI一些更多的信息，

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

在這裏，我得到以下錯誤：

_WebTryThreadLock(bool), 0x11d9b560: Tried to obtain the web lock from a thread other than the main thread or the web thread. This may be a result of calling to UIKit from a secondary thread. Crashing now... 1 0x58a76a9 WebThreadLock 2 0x5bfdfe -[UITextView _updateForNewSize:withOldSize:] 3 0x5c00b4 -[UITextView setFrame:] 4 0x4c59df UIViewCommonInitWithFrame 5 0x4c5bae -[UIView initWithCoder:] 6 0x4d9fb7 -[UIScrollView initWithCoder:] 7 0x5bc851 -[UITextView initWithCoder:] 8 0x7b1a02 UINibDecoderDecodeObjectForValue 9 0x7b10e5 -[UINibDecoder decodeObjectForKey:] 10 0x6a2648 -[UIRuntimeConnection initWithCoder:] 11 0x7b1a02 UINibDecoderDecodeObjectForValue 12 0x7b1418 UINibDecoderDecodeObjectForValue 13 0x7b10e5 -[UINibDecoder decodeObjectForKey:] 14 0x6a1aa3 -[UINib instantiateWithOwner:options:] 15 0x566e37 -[UIViewController _loadViewFromNibNamed:bundle:] 16 0x567418 -[UIViewController loadView] 17 0x567648 -[UIViewController loadViewIfRequired] 18 0x567882 -[UIViewController view] 19 0x567b2a -[UIViewController contentScrollView] 20 0x57eef5 -[UINavigationController _computeAndApplyScrollContentInsetDeltaForViewController:] 21 0x57efdb -[UINavigationController _layoutViewController:] 22 0x57f286 -[UINavigationController _updateScrollViewFromViewController:toViewController:] 23 0x57f381 -[UINavigationController _startTransition:fromViewController:toViewController:] 24 0x57feab -[UINavigationController startDeferredTransitionIfNeeded:] 25 0x5804a3 -[UINavigationController pushViewController:transition:forceImmediate:] 26 0x580098 -[UINavigationController pushViewController:animated:] 27 0x386f -[BVMapViewController parserDidFinishWithStation:] 28 0x785c -[BVParser parseStation:] 29 0xf8a0d5 -[NSThread main] 30 0xf8a034 NSThread_main 31 0x94e53ed9 _pthread_start

我試圖在主線程中執行這一點，但推控制器獲取其觀點，全黑的。

先謝謝您，祝您有美好的一天。

Answer 1

那麼，正如你暗示在你的問題，你必須推視圖控制器的主線程。任何與UIKit的交互都必須在主線程上完成。

至於爲什麼它顯示爲黑色，這是您需要通過標準故障排除技術解決的不同問題。一旦它在主線程上並且它正常運行，就可以在顯示的類的各種方法（viewDidLoad等）上設置斷點並查看它在哪裏跳閘。