Question

I have navigation-based application with first RootViewController.

I wanna to protect it with password like lock screen.
I’ve already code of password checking.

But I don’t know how to

1) Insert my CheckPasswordView first before RootViewController.

2) Require to enter the password every time my application reopens from suspend.

Update:

- (void)applicationDidBecomeActive:(UIApplication *)application {
    /*
     Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
     */

    CheckPasswordViewController *vc = [[CheckPasswordViewController alloc] 
                                       initWithNibName:@"CheckPasswordViewController" bundle:nil];
    vc.title = @"Enter password";       

    [self.navigationController pushViewController:vc animated:YES];    

    [vc release]; 
}

Answer 1

You need to use the UIApplicationDelegate’s applicationDidBecomeActive message. In that delegate (function) you can put code to make your CheckPasswordView active and ask user for password before resuming the application. From the documentation:

This method is called to let your application know that it moved from
the inactive to active state. This can occur because your application
was launched by the user or the system. Applications can also return
to the active state if the user chooses to ignore an interruption
(such as an incoming phone call or SMS message) that sent the
application temporarily to the inactive state.

There are other methods in this delegate you can take a look at to implement what you need.