how can i push the RKSwipeBetweenViewControllers in a uinavigationviewcontroller

[holyen]

when i push the object of RKSwipeBetweenViewControllers it crash. code: RKSwipeBetweenViewControllers *swipeVC = [RKSwipeBetweenViewControllers newSwipeBetweenViewControllers]; [nav_tweet.viewControllerArray addObjectsFromArray:@[[TimelineViewController newTimelineViewControllerWithType:TimelineViewControllerType_Nearby], [TimelineViewController newTimelineViewControllerWithType:TimelineViewControllerType_Hot]]]; nav_tweet.buttonText = @[@"A", @"B"]; [self.navigationController pushViewController:nav_tweet animated:YES];

then it crash log is : NSScanner: nil string argument how to fix it ?