顯示我有一個UIViewController用這種方法:presentModalViewController不從獨立的UIViewController
-(void)prepareToShowVault {
...
UINavigationController *passcodeNavigationController = [[UINavigationController alloc] initWithRootViewController:passcodeViewController];
[self.navigationController presentModalViewController:passcodeNavigationController animated:YES];
[passcodeViewController release];
[passcodeNavigationController release];
}
當從這個UIViewController中的另一種方法調用,它工作得很好。但是當從另一個UIViewController調用時,這個方法會觸發,但代碼不會顯示一個新的modalViewController,大概是因爲具有上述方法的UIViewController不是活動的。我怎樣才能做這項工作?