我的应用程序在没有多任务支持的情况下运行良好。但是当我在 info.plist 中激活它时,每次我在 navigationController 上按一些东西并点击主页按钮时它都会崩溃,然后回到应用程序并再次使用 navigationController。错误消息对我也没有帮助。
当我只希望应用程序在后台什么都不做并返回时,我需要为我的应用程序中的多任务支持做些什么。
遗憾的是,自 Xcode 4.1 -_- 以来,仪器也无法正常工作。
控制台中的错误消息有时是:
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[CAContextImpl _isCached]: unrecognized selector sent to instance 0x5b783d0'
有时它是一个 EXC_BAD_...在我创建开关的视图中???但前提是我之前点击了主页按钮!如果我只推视图然后返回。单击主页按钮。点击应用程序符号。然后尝试再次推送相同的视图它崩溃。但是当我推送视图时,返回并推送视图,它可以工作。当我在 SpringBoard 中(单击主页按钮)时,它只会崩溃。
编辑:
//AppDelegate class
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[window makeKeyAndVisible];
[self loadHauptmenu];
return YES;
}
- (void) loadHauptmenu {
NSLog(@"loading Hauptmenu");
navigationController = [[UINavigationController alloc] init];
HauptMenuViewController *hauptMenuController = [[HauptMenuViewController alloc] init];
[navigationController pushViewController:hauptMenuController animated:NO];
// [hauptMenuController release]; //tried this as error, but wasn't it
[window addSubview:navigationController.view];
}
//Main Menu class
- (void) pushNewViewController:(UIViewController*)pushMe {
NSLog(@"Der aktuelle navigationController ist: %@", self.navigationController);
[self.navigationController pushViewController:pushMe animated:YES];
}
- (void) pushNewViewWithClassname:(NSString*)classname {
UIViewController *viewControllerToPush = [[NSClassFromString(classname) alloc] init];
[self pushNewViewController:viewControllerToPush];
[viewControllerToPush release];
}
- (IBAction) pushEinstellungen:(id)sender {
[self pushNewViewWithClassname:@"EinstellungenViewController"];
}
//view class, which gets pushed
- (id) init {
self = [super init];
if (self != nil) {
self.title = @"Einstellungen";
//self.view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 416)];
self.view.backgroundColor = MEDILEARN_COLOR;
self.tableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, 320, 416) style:UITableViewStyleGrouped];
self.tableView.delegate = self;
self.tableView.dataSource = self;
self.tableView.allowsSelection = NO;
self.tableView.backgroundColor = [UIColor clearColor];
[self.view addSubview:self.tableView];
self.fragenSwitch = [[UISwitch alloc] initWithFrame:CGRectMake(194, 8, 94, 28)]; //here is an EXC_BAD_...
[self.fragenSwitch addTarget:self action:@selector(toggleEnabledForFragenSwitch:) forControlEvents:UIControlEventValueChanged];
[self.fragenSwitch setOn:[[NSUserDefaults standardUserDefaults] boolForKey:@"randFragen"] animated:NO];
self.antwortenSwitch = [[UISwitch alloc] initWithFrame:CGRectMake(194, 8, 94, 28)];
[self.antwortenSwitch addTarget:self action:@selector(toggleEnabledForAntwortenSwitch:) forControlEvents:UIControlEventValueChanged];
[self.antwortenSwitch setOn:[[NSUserDefaults standardUserDefaults] boolForKey:@"randAntworten"] animated:NO];
}
return self;
}