根视图条转

//a modal 出 b

[ a presentViewController:b animated:Yes completion:nil];

a.presentedViewController ->b

b.presentingViewController ->a

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要跳转的控制器VC[New]个;

UIViewController *root = [UIApplication sharedApplication].keyWindow.rootViewController;

UINavigationController *nav = [UINavigationController alloc] initWithRootViewController:要跳转的控制器];

[root presentViewController:nav animated:YES completion:nil];