Iphone 启动屏幕：调用dismissModalViewControllerAnimated delayed后执行错误访问

我正在尝试使用模式视图控制器为我的应用程序创建一个1-2秒的飞溅屏幕，但是当我尝试关闭视图时，我的应用程序由于严重的访问错误而崩溃。因此，在我的申请委托中，我有：

- (BOOL) application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
 //create window and show it
 window = [[UIWindow alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
 window.backgroundColor = [UIColor greenColor];
 [window makeKeyAndVisible];


 //create the main view controller and add its view to the window 
 mainViewCtrl = [MainViewController alloc];
 [window addSubview:mainViewCtrl.view];


 //show splash screen
 UIImage *image      = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle]  pathForResource:@"default.png" ofType:nil]];
 splashViewCtrl  = [[UIViewController alloc] init];
 splashViewCtrl.view = [[UIImageView alloc] initWithImage:image];
 [mainViewCtrl presentModalViewController:splashViewCtrl animated:NO];

//setup callback to dismiss
[self performSelector:@selector(hideSplash) withObject:nil afterDelay:2.0];

return(true);
}

//hide splash screen callback
- (void)hideSplash {
 [[self mainViewCtrl] dismissModalViewControllerAnimated:YES];
}

除了在2秒钟后调用hideSplash时，应用程序因EXC_BAD_访问而崩溃外，这一切都可以正常工作。如果我注释掉执行选择器行，然后立即调用hidesplash，就像这样：

[mainViewCtrl presentModalViewController:splashViewCtrl animated:NO];

[self hideSplash];

模态视图被正确地忽略。我相当肯定这是一个内存管理问题，但我不确定我到底做错了什么。有没有人知道这可能是什么，或者如何正确地调试它，以便我可以推迟解雇

谢谢这看起来很奇怪：

mainViewCtrl = [MainViewController alloc];

尝试向其添加初始化调用

//show splash screen
UIImage *image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle]  pathForResource:@"default.png" ofType:nil]];
splashViewCtrl = [[UIViewController alloc] init];
splashViewCtrl.view = [[UIImageView alloc] initWithImage:image];
[mainViewCtrl presentModalViewController:splashViewCtrl animated:NO];

将上述内容更改为以下内容：

//show splash screen
UIImage *image = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle]  pathForResource:@"default.png" ofType:nil]];
splashViewCtrl = [[UIViewController alloc] init];
splashViewCtrl.view = [[UIImageView alloc] initWithImage:image];
[mainViewCtrl presentModalViewController:splashViewCtrl animated:NO];
[mainViewCtrl release]; //Add this line !!!!