UITabBar

http://blog.csdn.net/zhanglei5415/article/details/6369119
http://hi.baidu.com/bunsman/blog/item/effd0aeae83bd8cad439c93d.html
http://www.cnblogs.com/lovecode/articles/2310991.html

有效隐藏UITabBar：http://www.devdiv.com/home.php?mod=space&uid=11574&do=blog&id=2085

- (void) hideTabBar:(BOOL) hidden
{
    
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:0];
	
    for(UIView *view in self.tabBarController.view.subviews)
    {
        if([view isKindOfClass:[UITabBar class]])
        {
            if (hidden) {
                [view setFrame:CGRectMake(view.frame.origin.x, 320, view.frame.size.width, view.frame.size.height)];
            } else {
                [view setFrame:CGRectMake(view.frame.origin.x, 320-49, view.frame.size.width, view.frame.size.height)];
            }
        } 
        else 
        {
            if (hidden) {
                [view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 320)];
            } else {
                [view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, 320-49)];
            }
        }
    }
    
    [UIView commitAnimations];
}

//  移除UITabBarController上的UITabBar
	for(UIView *view in self.view.subviews) {
		if([view isKindOfClass:[UITabBar class]]) {
			view.hidden = YES;
			break;
		}
	}

	NSArray *array = [tabBarCtrl.view subviews];
	UITabBar *tabBar = [array objectAtIndex:1];
	UIImage *image = [UIImage imageNamed:@"background.png"];
	tabBar.layer.contents = (id)image.CGImage;

@implementation UINavigationBar (CustomImage2)   
- (void)drawRect:(CGRect)rect {   
    UIImage *image = [UIImage imageNamed: @"bar.png"];   
    [image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];   
}   
@end

@implementation UIToolbar (CustomImage2)   
- (void)drawRect:(CGRect)rect {   
    UIImage *image = [UIImage imageNamed: @"bar.png"];   
    [image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];   
}   
@end

@implementation UITabBar (CustomImage2)   
- (void)drawRect:(CGRect)rect {   
    UIImage *image = [UIImage imageNamed: @"bar.png"];   
    [image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];   
}   
@end

    UISearchBar的背景图片控制不是由自已控制的，而是由 UISearchBarBack来控制。
因此无法直接用上面的代码，需要手动把UISearchBar上面的两个View 删除了才行。

    在你的ViewDidLoad 或者任何一个程序可以执行到的地方写下如下代码，
首先你得一个 UISearchbar。

//  删除UISearchbar上的 UISearchBarBackground
    [[_searchBar.subviews objectAtIndex:0] setHidden:YES];
    [[_searchBar.subviews objectAtIndex:0] removeFromSuperview];
    for (UIView *subview in _searchBar.subviews) {
        if ([subview isKindOfClass:NSClassFromString(@"UISearchBarBackground")]) {
            [subview removeFromSuperview];
            break;
        }
    }

@implementation UISearchBar (CustomImage2)   
- (void)drawRect:(CGRect)rect {   
    UIImage *image = [UIImage imageNamed: @"bar.png"];   
    [image drawInRect:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];   
}   
@end