UISearchBar去除背景颜色

UISearchBar *searchBar=[[UISearchBar alloc]initWithFrame:frame];
//这个设置背景透明可能无效
searchBar.backgroundColor=[UIColor clearColor];

//可采用如下方法去除搜索框背景
for (UIView *view in searchBar.subviews) {
// iOS7.0之前
if ([view isKindOfClass:NSClassFromString(@"UISearchBarBackground")]) {
[view removeFromSuperview];
break;
}
// iOS7.0+
if ([view isKindOfClass:NSClassFromString(@"UIView")] && view.subviews.count > 0) {
[[view.subviews objectAtIndex:0] removeFromSuperview];
break;
}
}