我不理解的多视图控制器和segue导航错误消息

Question

XCode 7.3, ObjC single view project. iOS Simulator.

I'm in a UIViewController called "LoginViewController". I click a button, it calls a method called Login. In Login I call

[self performSegueWithIdentifier: @"Login" sender:sender];

In the performSegueWithIdentifier method I use an if statement to select on that "Login" condition and at this early stage of stubbing this out do this:

if ([[segue identifier] isEqualToString:@"Login"]) {

     MainMenuViewController *mmvc = segue.destinationViewController;
     mmvc.strUsername = self.txtUsername.text;
     mmvc.strPassword = self.txtPassword.text;
 }

The MainMenuViewController loads fine and my data is visible in the UI but right after it completes the prepareForSegue method the console spits this out:

UIView: 0x7fc19beaaf60; frame = (0 0; 320 568); autoresize = W+H; layer = CALayer: 0x7fc19beab0d0's window is not equal to MainMenuViewController: 0x7fc19bd2d300>'s view's window!

Any ideas?

Thanks!

Answer 1

The trick is to create the segue between the view controller's view and the next view controller rather than between a button and the next view controller. See this solution that solved the problem: Defining a "generic" segue in Interface Builder