如何启用UISearchBar灰色视图？

UISearchBar

UIView

UIView

backgroundColor

UIView *view1 = [[UIView alloc] init];
view1.frame = CGRectMake(0, 20, 320, 460);
view1.backgroundColor = [UIColor grayColor];

UISearchBar *searchBar = [[UISearchBar alloc] init];
searchBar.frame = CGRectMake(0, 0, 320, 50);
[view1 addSubview:searchBar];
[searchBar release];

[self.window addSubview:view1];
[view1 release];