iphone - 尝试以编程方式创建 rightBarButtonItem

Question

这似乎不起作用。我究竟做错了什么？

-(void)awakeFromNib{
    UIBarButtonItem *rightBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd target:self action:@selector(showNewEventViewController)];
    self.navigationItem.rightBarButtonItem = rightBarButtonItem;
    NSLog(@"awaked");
    [rightBarButtonItem release];
}

Answer 1

我的猜测是，您将 UIBarButtonItem 添加到了错误的对象!您需要将其添加到 rootViewController(而不是像您可能所做的那样添加到 UINavigationController)

YourRootViewController *theRootController = [[YourRootViewController alloc] init];

UINavigationController* navContainer = [[UINavigationController alloc] initWithRootViewController:theRootController];

UIBarButtonItem *btnCancel = [[UIBarButtonItem alloc] initWithTitle:@"Cancel" style:UIBarButtonItemStyleBordered target:self action:@selector(dismiss)];    
theRootController.navigationItem.rightBarButtonItem = btnCancel

[navContainer setModalTransitionStyle:UIModalTransitionStyleCrossDissolve];
[self presentModalViewController:navContainer animated:YES];