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POiOS - UILabel variable becoming (null)
 

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    <p>I have searched high and low for an answer to my predicament and I believe it is due to my difficulty in adapting to ARC - I am hoping to deploy my app on iOS5 and am currently testing it in on a beta4 3GS.</p> <p>When the viewController is loaded (viewDidLoad:) my app alloc init's a UILabel and customises it to add it to the top of the screen:</p> <pre><code>UIView *navHeaderView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 280, 44)]; self.artistLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 2, 280, 15)]; artistLabel.font = [UIFont systemFontOfSize:12]; artistLabel.textColor = [UIColor grayColor]; artistLabel.backgroundColor = [UIColor clearColor]; artistLabel.textAlignment = UITextAlignmentCenter; [navHeaderView addSubview:artistLabel]; self.navigationBar.topItem.titleView = navHeaderView; </code></pre> <p>Okay, this works fine and fills in the relevant detail by accessing a updateTrack method:</p> <pre><code>- (void)updateTrack { _player = [MPMusicPlayerController iPodMusicPlayer]; _item = [_player nowPlayingItem]; self._artistString = [_item valueForProperty:MPMediaItemPropertyArtist]; self.artistLabel.text = self._artistString; } </code></pre> <p>This method is called when the music playing is changed using NSNotifications. However the artistString UILabel is now (null). I cannot see why the property has been released - it is set a nonatomic, strong property in the header file and synthesized at the top of the .m file.</p> <p>Maybe I should also add that a nonatomic, strong property I have assigned to an IBOutlet of UIImageView also goes (null) once the app has successfully loaded, displayed the album art once (i.e. this is not added as a subview).</p> <p>Any help would be greatly appreciated :D</p>
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    1. COThis may not be related to iOS5, so I'm commenting. Seeing the property declarations would help. I suspect the valueForProperty call is returning nil. On a separate note, self._artistString just reads wrong (shouldn't be an underscore) and I would expect that self.artistLabel = [[UILabel alloc] ... is over retaining.
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