MonoTouch.Dialog崩溃
MonoTouch.Dialog崩溃
提问于 2012-02-12 21:38:18
我有一个小测试应用程序，它只是循环在3页之间。以下是AppDelegate：
public override bool FinishedLaunching (UIApplication app, NSDictionary options)
{
_session = new Session();
_session.NextScreen += (screenIndex) =>
{
window.RootViewController = _viewControllers[screenIndex];
};
_viewControllers.Add(new Screen0(_session));
_viewControllers.Add(new Screen1(_session));
_viewControllers.Add(new Screen2(_session));
// create a new window instance based on the screen size
window = new UIWindow (UIScreen.MainScreen.Bounds);
// If you have defined a view, add it here:
// window.AddSubview (navigationController.View);
window.RootViewController = _viewControllers[0];
// make the window visible
window.MakeKeyAndVisible ();
return true;如果我在每个屏幕上放置一个按钮，我就可以从一个页面导航到另一个页面，也就是说，
public override void ViewDidLoad ()
{
base.ViewDidLoad ();
UIButton button = new UIButton(new RectangleF(30, 200, 80, 34));
button.SetTitle("Go to 1", UIControlState.Normal);
button.TouchUpInside += (sender, e) =>
{
_session.ExittingScreen = 0;
};
View.AddSubview(button);
}WHen --我使用MonoTouch.Dialog --但是，我会间歇性地崩溃。这是我的密码：
public override void ViewDidLoad ()
{
base.ViewDidLoad ();
var rootElement = new RootElement("Register")
{
new Section()
{
new EntryElement("First Name", "required", ""),
new EntryElement("Last Name", "required", ""),
new EntryElement("Email Address", "required", ""),
new EntryElement("Password", "required", "")
},
new Section()
{
new StyledStringElement("Submit you information", () => { _session.ExittingScreen = 1; })
}
};
var dialogViewController = new DialogViewController(rootElement);
var navigationController = new UINavigationController(dialogViewController);
View.Add (navigationController.View);还有垃圾场：
MonoTouch.UIKit.UIApplication.UIApplicationMain (int，string[]，intptr，intptr) <0xffffffff> at MonoTouch.UIKit.UIApplication.Main (string[]，string，string) <0x000b7> at MTD.Application.Main (string[]) <0x00017> at (包装时-调用) .runtime_invoke_void_object (object，intptr，intptr，intptr) <0xffffffff>
原生堆栈：
0 MTD 0x00090b7c mono_handle_native_sigsegv + 284
1 MTD 0x00005f28 mono_sigsegv_signal_handler + 248
2 libsystem_c.dylib 0x97da559b _sigtramp + 43
3 ??? 0xffffffff 0x0 + 4294967295
4 UIKit 0x02220952 -[UITableView _userSelectRowAtPendingSelectionIndexPath:] + 201
5 Foundation 0x0173786d __NSFireDelayedPerform + 389
6 CoreFoundation 0x01195966 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 22
7 CoreFoundation 0x01195407 __CFRunLoopDoTimer + 551
8 CoreFoundation 0x010f87c0 __CFRunLoopRun + 1888
9 CoreFoundation 0x010f7db4 CFRunLoopRunSpecific + 212
10 CoreFoundation 0x010f7ccb CFRunLoopRunInMode + 123
11 GraphicsServices 0x04789879 GSEventRunModal + 207
12 GraphicsServices 0x0478993e GSEventRun + 114
13 UIKit 0x02190a9b UIApplicationMain + 1175
14 ??? 0x09ff6774 0x0 + 167733108
15 ??? 0x09ff5958 0x0 + 167729496
16 ??? 0x09ff57f0 0x0 + 167729136
17 ??? 0x09ff587f 0x0 + 167729279
18 MTD 0x0000a292 mono_jit_runtime_invoke + 722
19 MTD 0x0016a17e mono_runtime_invoke + 126
20 MTD 0x0016e264 mono_runtime_exec_main + 420
21 MTD 0x00173685 mono_runtime_run_main + 725
22 MTD 0x00067495 mono_jit_exec + 149
23 MTD 0x002116c9 main + 2825
24 MTD 0x000032e5 start + 5325 ?？0x0000050x0+5
我是不是做错什么了，还是这是个窃听器？谢谢。
回答 1
Stack Overflow用户
回答已采纳
发布于 2012-02-13 00:42:33
避免使用以下模式：
var navigationController = new UINavigationController(dialogViewController);
View.Add (navigationController.View);因为navigationController不会被引用(在托管端)，一旦View.Add调用完成，垃圾收集器就可以将其释放(无论何时都可以)。但是，从本机端来看，它将是存在的。返回(从本机到托管)到已释放实例的调用将使应用程序崩溃。
正确的模式是将navigationController声明为类型的字段(而不是局部变量)，并在方法中创建/分配它。只要父实例存在，这将使对navigationController的引用保持活动状态(并确保任何回调都不会转到已释放的对象)。
例如。
private UINavigationController navigationController;
...
public override void ViewDidLoad ()
{
...
var dialogViewController = new DialogViewController(rootElement);
navigationController = new UINavigationController(dialogViewController);
View.Add (navigationController.View);
...
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/9252933
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