怎么实现presentModalViewController的push效果

替换前： [[UIApplication sharedApplication].keyWindow.rootViewController presentModalViewController: picker animated: YES]; 替换后： [[UIApplication sharedApplication].keyWindow.rootViewController presentViewController: picker animated: YES completion:nil]; 有一警告： Instance method '-presentedViewController:animated:completion:' not found (return type defaults to 'id') 请问各位，如何替换才为正解？文档已提供 presentModalViewController:animated: Presents a modal view managed by the given view controller to the user. (Deprecated in iOS 6.0. Use presentViewController:animated:completion: instead.) - (void)presentModalViewController:(UIViewController *)modalViewController animated:(BOOL)animated presentViewController:animated:completion: Presents a view controller. - (void)presentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion Parameters viewControllerToPresent The view controller being presented. flag Pass YES to animate the presentation; otherwise, pass NO. completion A completion handler or NULL.