addSubview: method horribly slow - objective-c

Question

I am trying to initialize a ViewController from another. Here is the code written in my first ViewController:
MediasViewController.h
#import "MediasVideosViewController.h"
#interface MediasViewController : UIViewController <UIWebViewDelegate>
{
NSArray* videosList;
MediasVideosViewController *mediasVideosViewController;
}
#property (nonatomic, retain) NSArray* videosList;
#property (nonatomic, retain) MediasVideosViewController* mediasVideosViewController;
MediasViewController.m :
if (self.mediasVideosViewController == nil)
{
MediasVideosViewController* mediasVideos = [[MediasVideosViewController alloc] initWithNibName:#"MediasVideosView" bundle:nil];
self.mediasVideosViewController = mediasVideos;
self.mediasVideosViewController.videosList = self.videosList;
[mediasVideos release];
}
NSDate *start = [NSDate date];
[mediasVideosViewController.view addSubview:nil];
NSLog(#"adding nil to mediasVideosViewController.view took %f seconds", [[NSDate date] timeIntervalSinceDate:start]);
Console result :
adding nil to
mediasVideosViewController.view took
4.261444 seconds
Seriously? More than 4s to add nil to mediasVideosController ? It's swings between 1s and 5s.
But if I remove this line :
self.mediasVideosViewController.videosList = self.videosList;
from MediasViewController.m, I get a really shorter loading time, like :
adding nil to
mediasVideosViewController.view took
0.007613 seconds
It drives me crazy...
Does anyone have a solution?

Answer 1

When you call mediasVideosViewController.view, you are basically calling loadView for the first time. You aren't just adding a subview, you are creating the entire view with that call.
Presumably, when you set the list of videos you are giving your loadView method a lot more work to do. This will result in the behavior you see.
In a nutshell, check out your loadView method for clues.
EDIT: I noticed you were loading the view controller from a NIB file, in that case you want to check viewDidLoad.