如何在选定的 UITabBar 项目之上覆盖？

Question

有人知道如何在所选项目之上添加额外的叠加层吗？

背景是在应用程序委托中完成的。

UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"navbar_bgrd.png"]];

if ([[[UIDevice currentDevice] systemVersion] floatValue] > 4.9) {
    //iOS 5
    [self.tabBarController.tabBar insertSubview:imageView atIndex:1];
}
else {
    //iOS 4.whatever and below
    [self.tabBarController.tabBar insertSubview:imageView atIndex:0];
}

已选择

未选择

Answer 1

修复了IOS 5、UI外观功能

 //set the background of tab bar
    UIImageView *imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"navbar_bgrd.png"]];

    if ([[[UIDevice currentDevice] systemVersion] floatValue] > 4.9) {
        //iOS 5
        //[self.tabBarController.tabBar insertSubview:imageView atIndex:1];

        [[UITabBar appearance] setBackgroundImage:[UIImage imageNamed:@"navbar_bgrd.png"]];
        [[UITabBar appearance] setSelectionIndicatorImage:
         [UIImage imageNamed:@"navbaractive.png"]];

        [[UITabBarItem appearance] setTitleTextAttributes:
         [NSDictionary dictionaryWithObjectsAndKeys:
          [UIColor colorWithRed:75.0/255.0 green:75.0/255.0 blue:75.0/255.0 alpha:1.0], UITextAttributeTextColor, 
          [UIColor clearColor], UITextAttributeTextShadowColor, 
          [NSValue valueWithUIOffset:UIOffsetMake(0, 1)], UITextAttributeTextShadowOffset, 
          nil] forState:UIControlStateNormal];

        [[UITabBarItem appearance] setTitleTextAttributes:
         [NSDictionary dictionaryWithObjectsAndKeys:
          [UIColor whiteColor], UITextAttributeTextColor, 
          [UIColor clearColor], UITextAttributeTextShadowColor, 
          [NSValue valueWithUIOffset:UIOffsetMake(0, 1)], UITextAttributeTextShadowOffset, 
          nil] forState:UIControlStateSelected];