how to customize UIBarButtonItem in ios5 - ios5

Question

I want customize UIBarButtonItem,here is my code.
in ios4.3 it works,but ios5, it‘s very strange.
the uibarbuttonitem disappeared out of sight,but you click on it still has the effect。As is transparent。
I need help,how to make the uibarbuttonitem display。thanks
UIButton *btn = [UIButton buttonWithType:UIButtonTypeCustom];
btn.frame = CGRectMake(0, 0, 50, 30);
[btn setBackgroundImage:[UIImage imageNamed:#"btnRegister.png"] forState:UIControlStateNormal];
[btn setTitle:#"register" forState:UIControlStateNormal];
[btn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];
[btn addTarget:self action:#selector(registerClick:) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *item1 = [[UIBarButtonItem alloc] initWithCustomView:btn];
self.navigationItem.rightBarButtonItem = item1;

Answer 1

There is a great tutorial about new customization features in iOS 5 here : http://www.raywenderlich.com/4344/user-interface-customization-in-ios-5
Here's a copy of code from that site that deals with customization of UIBarButtonItems, its pretty self-explanatory :
UIImage *button30 = [[UIImage imageNamed:#"button_textured_30"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 5, 0, 5)];
UIImage *button24 = [[UIImage imageNamed:#"button_textured_24"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 5, 0, 5)];
[[UIBarButtonItem appearance] setBackgroundImage:button30 forState:UIControlStateNormal
barMetrics:UIBarMetricsDefault];
[[UIBarButtonItem appearance] setBackgroundImage:button24 forState:UIControlStateNormal
barMetrics:UIBarMetricsLandscapePhone];
[[UIBarButtonItem appearance] setTitleTextAttributes:
[NSDictionary dictionaryWithObjectsAndKeys:
[UIColor colorWithRed:220.0/255.0 green:104.0/255.0 blue:1.0/255.0 alpha:1.0],
UITextAttributeTextColor,
[UIColor colorWithRed:1.0 green:1.0 blue:1.0 alpha:1.0],
UITextAttributeTextShadowColor,
[NSValue valueWithUIOffset:UIOffsetMake(0, 1)],
UITextAttributeTextShadowOffset,
[UIFont fontWithName:#"AmericanTypewriter" size:0.0],
UITextAttributeFont,
nil]
forState:UIControlStateNormal];

Answer 2

My problem is similar to this one. In my case, the button appear no enable. And when you put in it still has the effect. One little solution is change the tint of the button with white but I am looking for a better way :)
My code is:
buttonImage = [UIImage imageNamed:#"top_icon_share.png"];
UIButton *buttonShare = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, buttonImage.size.width, buttonImage.size.height)];
[buttonShare setBackgroundImage:buttonImage forState:UIControlStateNormal];
[buttonShare addTarget:self action:#selector(buttonSharePressed)
forControlEvents:UIControlEventTouchUpInside];
[buttonShare setShowsTouchWhenHighlighted:YES];];
UIBarButtonItem *buttonBarShare = [[UIBarButtonItem alloc]initWithImage:[UIImage imageNamed:#"top_icon_share.png"] style:UIBarButtonItemStylePlain target:self action:#selector(buttonSharePressed:)];