NavigationController子视图在iOS中没有显示uibarbutton

Question

当用户点击UIButton时会触发这段代码。现在在subview类上，当我试图在导航栏上显示UIBarButton时，它没有工作。请让我知道我在哪里做错了。

PendingPaymentiPad *pendingpayiPad = [self.storyboard instantiateViewControllerWithIdentifier:@"PendingPaymentiPad"];
pendingpayiPad.view.frame = CGRectMake(100, 140, SCREEN_WIDTH, SCREEN_HEIGHT);
[self.navigationController.navigationBar addSubview:pendingpayiPad.view];