更改搜索栏的背景图片

UISearchBar* bar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
UIImageView* iview = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"test.png"]];
iview.frame = CGRectMake(0, 0, 320, 44);
[bar insertSubview:iview atIndex:1];
[iview release];
[self.view addSubview:bar];
[bar release];

searchBar.backgroundImage = [UIImage imageNamed:@"searchBackground"];

searchBar.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"search_bg.png"]];