[IOS]添加NavigationItem到导航视图控制器

-(void)loadView
{
self.navigationController.navigationBar.barStyle = UIBarStyleBlack;

UIView *baseView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen]applicationFrame]];
baseView.backgroundColor = [UIColor purpleColor];
self.view = baseView;

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[button setTitle:@"Push" forState:UIControlStateNormal];
[button setFrame:CGRectMake(90, 100, 140, 40)];
[button addTarget:self action:@selector(pushVC) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:button];

//添加UIBarButtonItem
UIBarButtonItem *leftItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemDone target:self action:@selector(method1)];
self.navigationItem.leftBarButtonItem = leftItem;

UIButton *rightButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
[rightButton setTitle:@"Alert" forState:UIControlStateNormal];
[rightButton setFrame:CGRectMake(50, 0, 50, 30)];
[rightButton addTarget:self action:@selector(test) forControlEvents:UIControlEventTouchUpInside];

UIBarButtonItem *rightItem = [[UIBarButtonItem alloc] initWithCustomView:rightButton];
self.navigationItem.rightBarButtonItem = rightItem;
}

-(void) method1
{
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"提示" message:@"你点击了左上角Item按钮" delegate:nil cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil];
[alert show];
}

-(void) test
{
UIActionSheet *actionSheet = [[UIActionSheet alloc]
initWithTitle:@"提示"
delegate:nil
cancelButtonTitle:@"取消"
destructiveButtonTitle:nil
otherButtonTitles:@"确定", nil];
actionSheet.actionSheetStyle = UIActionSheetStyleBlackTranslucent;
[actionSheet showInView:self.view];
}