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    <p>When you push view controller into navigation controller, it's backBarButtonItem will be set up for back to previous view controller, not leftBarButtonItem. If you set up leftBarButtonItem, the backBarButtonItem will be hide and the same place will be replaced by the leftBarButtonItem. </p> <p>And your code doesn't set leftBarButtonItem at all, so of course it is nil.</p> <p>EDIT: My test codes. I checked the backButtonItem and leftBarButtonItem by following codes, and they are nil. You are right. But when I touched the back button to previous view, its color did change, so it was highlighted. And it worked well back to previous view controller. So I think your code is wrong at some else place, it makes the back button inactive. </p> <p>Listing 1, RootViewController class</p> <pre><code>// RootViewController.h #import &lt;UIKit/UIKit.h&gt; @interface RootViewController : UIViewController { } @end // RootViewController.m #import "RootViewController.h" #import "MyViewController.h" @implementation RootViewController - (void)viewDidLoad { [super viewDidLoad]; self.title = @"RootView"; MyViewController *childView = [[[MyViewController alloc] init] autorelease]; UINavigationController *navCtrl = [[[UINavigationController alloc] initWithRootViewController:childView] autorelease]; [self.navigationController presentModalViewController:navCtrl animated:YES]; } @end </code></pre> <p>Listing 2, MyViewController</p> <pre><code>// MyViewController.h #import &lt;UIKit/UIKit.h&gt; @interface MyViewController : UIViewController { } @end // MyViewController.m #import "MyViewController.h" #import "MyAnotherViewController.h" @implementation MyViewController // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; self.title = @"MyView"; NSLog(@"%s backBarButtonItem:%@ leftBarButtonItem:%@",__FUNCTION__ ,self.navigationItem.backBarButtonItem, self.navigationItem.leftBarButtonItem); MyAnotherViewController *childView = [[[MyAnotherViewController alloc] init] autorelease]; [self.navigationController pushViewController:childView animated:YES]; } @end </code></pre> <p>Listing 3, MyAnotherViewController</p> <pre><code>// MyAnotherViewController.h #import &lt;UIKit/UIKit.h&gt; @interface MyAnotherViewController : UIViewController { } @end // MyAnotherViewController.m #import "MyAnotherViewController.h" @implementation MyAnotherViewController - (void)viewDidLoad { [super viewDidLoad]; self.title = @"Another View"; } @end </code></pre>
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    1. POiPhone - backBarButtonItem is nil and does not highlight when touched
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    1. COOK, my fault :-) but it's the same with backBarButtonItem : it's nil too
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    2. COI checked it and I found you are right. The backBarButtonItem is nil too. :-)
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    3. COBut the backBarButtonItem is highlighted when I touched. And I found a funny thing that when the title of root view controller is nil, and push a view controller into navigation controller, there is no back button on the navigation bar. But after I assigned a title for root view controller, and push a view controller, I can see the back button on the bar.
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