Creating a custom NSViewController without a nib

Question

I recently started learning Objective-C and I've run into a slight problem. I'm trying to use a custom view controller without a nib, so the view is created in the code. The view controller itself is created in the AppDelegate.

When I run the program, it first displays a default empty window. After I close this window, a second window pops up which correctly contains the view. I obviously don't want that first window to appear, but I don't know what causes it. The only information I could find on this subject was for iOS development, which isn't quite the same.

I also get this message of which I'm not really sure what it means: Could not connect the action orderFrontStandardAboutPanel: to target of class MainViewController

AppDelegate:

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    mainViewController = [[MainViewController alloc] initWithFrame:_window.frame];
    _window.contentView = mainViewController.view;
}

MainViewController:

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithNibName:nil bundle:nil];
    if (self)
    {
        [self setView:[[MainView alloc] initWithFrame:frame]];
        [self loadView];
    }
    return self;
}

Answer 1

In short, override loadView and set self.view to your view. You'll want to give it a frame before you set it.

The default implementation of loadView is where it tries to load the nib. You're intended to override this if you don't want that.