objective c - Custom UIwindow not display

Question

I'm trying to create a new window for Custom alert on rootViewController.

- (void)viewdidAppear
{
            UIWindow *newWindow = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
            newWindow.windowLevel = UIWindowLevelAlert + 1.0f;
            newWindow.backgroundColor = [UIColor redColor];
            newWindow.hidden = NO;

        UIViewController *vc = [[UIViewController alloc] init];
        vc.view.backgroundColor = [UIColor blueColor];
        newWindow.rootViewController = vc;

        [newWindow makeKeyAndVisible];

But the newWindow not working. I am confused with this strange question. I hope you can help me.

Answer 1

Solution is window set Global variable. When Window makeKeyAndVisible,window was not be released.