如何在应用程序委托iOS10目标C中的applicationWillEnterForeground方法中以模态呈现UIViewController

Question

I wanna present a UIViewController when come into foreground app.
And i am using this code in applicationWillEnterForeground method in Objective C appDelegate app , but it does not works for me.

UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
PasscodeViewController *vc = [sb instantiateViewControllerWithIdentifier:@"passcodeVCID"];
[self presentViewController:vc animated:YES completion:nil];

Answer 1

UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
PasscodeViewController *vc = [sb instantiateViewControllerWithIdentifier:@"passcodeVCID"];

// Need to present with rootviewcontroller

[self.window.rootViewController presentViewController:vc animated:YES completion:nil];