UINavigationController pop&push

UINavigationController先pop再push，push操作将无效。

解决方案是：

OrderDetailViewController *vc = [[OrderDetailViewController alloc] init];

NSMutableArray *arrView = [NSMutableArray arrayWithArray:self.navigationController.viewControllers];

int index = (int)[arrView indexOfObject:self];

[arrView removeObjectAtIndex:index];

[arrView addObject:vc];

[self.navigationController setViewControllers:arrView animated:NO];