UIBarButtonItem 设置setRightBarButtonItem 背景

UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(0,0,60,31)];
[button setBackgroundImage:[UIImage imageNamed:@"abc.png"] forState:UIControlStateNormal];

UIBarButtonItem *btn = [[UIBarButtonItem alloc] initWithCustomView:button];
self.navigationItem.rightBarButtonItem = btn;

[button release];
[btn release];