how to customize UIBarButtonItem in 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];