学步园

在ios 5.0 后有设置UISearchBar的背景图片的接口，可如下设置其背景：

//search is a defined UISearchBar
UIImage *img = [[UIImage imageNamed:@"nav_bar.png"] stretchableImageWithLeftCapWidth:1 topCapHeight:0];
[search setBackgroundImage:img];

在ios5.0以前，可用下面的方法：

//search is a defined UISearchBar
[[[search subviews] objectAtIndex:0] removeFromSuperview];
UIImage *img = [[UIImage imageNamed:@"nav_bar.png"] stretchableImageWithLeftCapWidth:1 topCapHeight:0];
UIImageView *imgView = [[UIImageView alloc] initWithImage:img];
imgView.frame= search.frame;
[search insertSubview:imgView atIndex:0];