Monotouch：以编程方式使用动态 ViewController 创建 UITabbar

Question

我尝试了很多方法并通过网络搜索但没有成功。这是我尝试过的最简单的方法，但无法运行它：

如果我运行此代码，它会正确显示选项卡栏，但是当我单击选项卡时，我会得到一个异常，我将其粘贴在以下代码示例下。

这是我的 MainMenu.cs 中的一个方法，它是入口 xib。

我很感激对此的任何帮助。预先非常感谢您！

private void Render_Screen (object sender, RenderScreenEventArgs e)
    {
        UITabBarController tabbarController = new UITabBarController();

        UINavigationController navController1 = new UINavigationController();
        UINavigationController navController2 = new UINavigationController();

        UIViewController a = new UIViewController();
        a.TabBarItem = new UITabBarItem(UITabBarSystemItem.Contacts, 0);
        UIViewController b = new UIViewController();
        b.TabBarItem = new UITabBarItem(UITabBarSystemItem.Favorites, 1);

        UIViewController[] arrayA = new UIViewController[] { a };
        UIViewController[] arrayB = new UIViewController[] { b };

        navController1.ViewControllers = arrayA;
        navController2.ViewControllers = arrayB;

        UINavigationController[] arrayC = new UINavigationController[] { navController1, navController2 };

        tabbarController.ViewControllers = arrayC;

        InvokeOnMainThread (delegate { 
            this.View.AddSubview (tabbarController.View);
        });
    }


Stacktrace:

  at (wrapper managed-to-native) MonoTouch.UIKit.UIApplication.UIApplicationMain (int,string[],intptr,intptr) <IL 0x0009f, 0xffffffff>
  at MonoTouch.UIKit.UIApplication.Main (string[],string,string) [0x00042] in /Developer/MonoTouch/Source/monotouch/src/UIKit/UIApplication.cs:29
  at NotifyMe.Application.Main (string[]) [0x00000] in /Users/hschulz/Projects/NotifyMe/NotifyMe/Main.cs:16
  at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <IL 0x00050, 0xffffffff>

Native stacktrace:

0   NotifyMe                            0x000e1008 mono_handle_native_sigsegv + 408
1   NotifyMe                            0x00011c7f mono_sigsegv_signal_handler + 351
2   libsystem_c.dylib                   0x9753459b _sigtramp + 43
3   ???                                 0xffffffff 0x0 + 4294967295
4   UIKit                               0x022a955a -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61
5   UIKit                               0x024ce569 -[UITabBar _sendAction:withEvent:] + 466
6   CoreFoundation                      0x012d8ec9 -[NSObject performSelector:withObject:withObject:] + 73
7   UIKit                               0x022a95c2 -[UIApplication sendAction:to:from:forEvent:] + 96
8   UIKit                               0x022a955a -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61
9   UIKit                               0x0234eb76 -[UIControl sendAction:to:forEvent:] + 66
10  UIKit                               0x0234f03f -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 503
11  UIKit                               0x0234ebab -[UIControl sendActionsForControlEvents:] + 48
12  UIKit                               0x024d0d1f -[UITabBar(Static) _buttonUp:] + 123
13  CoreFoundation                      0x012d8ec9 -[NSObject performSelector:withObject:withObject:] + 73
14  UIKit                               0x022a95c2 -[UIApplication sendAction:to:from:forEvent:] + 96
15  UIKit                               0x022a955a -[UIApplication sendAction:toTarget:fromSender:forEvent:] + 61
16  UIKit                               0x0234eb76 -[UIControl sendAction:to:forEvent:] + 66
17  UIKit                               0x0234f03f -[UIControl(Internal) _sendActionsForEvents:withEvent:] + 503
18  UIKit                               0x0234e2fe -[UIControl touchesEnded:withEvent:] + 549
19  UIKit                               0x022cea30 -[UIWindow _sendTouchesForEvent:] + 513
20  UIKit                               0x022cec56 -[UIWindow sendEvent:] + 273
21  UIKit                               0x022b5384 -[UIApplication sendEvent:] + 464
22  UIKit                               0x022a8aa9 _UIApplicationHandleEvent + 8196
23  GraphicsServices                    0x048a0fa9 PurpleEventCallback + 1274
24  CoreFoundation                      0x012ab1c5 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 53
25  CoreFoundation                      0x01210022 __CFRunLoopDoSource1 + 146
26  CoreFoundation                      0x0120e90a __CFRunLoopRun + 2218
27  CoreFoundation                      0x0120ddb4 CFRunLoopRunSpecific + 212
28  CoreFoundation                      0x0120dccb CFRunLoopRunInMode + 123
29  GraphicsServices                    0x0489f879 GSEventRunModal + 207
30  GraphicsServices                    0x0489f93e GSEventRun + 114
31  UIKit                               0x022a6a9b UIApplicationMain + 1175
32  ???                                 0x0e05a305 0x0 + 235250437
33  ???                                 0x0e058b90 0x0 + 235244432
34  ???                                 0x0e058888 0x0 + 235243656
35  ???                                 0x0e0589de 0x0 + 235243998
36  NotifyMe                            0x000119cf mono_jit_runtime_invoke + 1407
37  NotifyMe                            0x0022014a mono_runtime_invoke + 170
38  NotifyMe                            0x00222e81 mono_runtime_exec_main + 705
39  NotifyMe                            0x00222091 mono_runtime_run_main + 929
40  NotifyMe                            0x000ad5bf mono_jit_exec + 239
41  NotifyMe                            0x002f41aa main + 5194
42  NotifyMe                            0x00003035 start + 53

=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================

Answer 1

导致该异常的原因是您的应用程序是使用 5.0 SDK 构建的，但您使用的是 4.3 SDK 运行。几周前我遇到了这个问题。

为了解决这个问题，当模拟器通知您崩溃时，会有一个按钮显示“Switch SDK”。选择它，然后它将显示可用的 SDK。从列表中选择 5.0。重新启动，这将解决您的问题。

Answer 2

看来在外部声明工具栏可以解决我的问题。

    public class test
    {
        UITabBarController tabbarController; 

        privat void RenderScreen()
        {
         ...
        }
    }