自定义UISearchBar

先上系统默认的UISearchBar，然后用KVO修改

UISearchBar *searchBar = [[UISearchBar alloc]initWithFrame:_topView.bounds];
searchBar.placeholder = @"请输入您要搜索的商品";

效果为：

①将取消按钮cancle改为“取消”

-(void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar{
    searchBar.showsCancelButton = YES;
    for(UIView *view in  [[[searchBar subviews] objectAtIndex:] subviews]) {
        if([view isKindOfClass:[NSClassFromString(@"UINavigationButton") class]]) {
            UIButton * cancel =(UIButton *)view;
            [cancel setTitle:@"取消" forState:UIControlStateNormal];
            [cancel setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
            cancel.titleLabel.font = [UIFont systemFontOfSize:];
        }
    }
}

效果为

②修改searchbar背景色

UIView *backView = [[UIView alloc]initWithFrame:searchBar.bounds];
backView.backgroundColor = [UIColor colorWithRed:/255.0 green:/255.0 blue:/255.0 alpha:];
[searchBar insertSubview:backView atIndex:];

③设置searchbar输入框背景颜色及删减符号mode

UITextField *searchField = [searchBar valueForKey:@"_searchField"];
searchField.backgroundColor = [UIColor colorWithWhite:0.0 alpha:0.1];
searchField.clearButtonMode = UITextFieldViewModeNever;

④修改searchbar输入框的文字和占位符文字颜色

UITextField *searchField = [searchBar valueForKey:@"_searchField"];
searchField.textColor = [UIColor whiteColor];
[searchField setValue:[UIColor whiteColor] forKeyPath:@"_placeholderLabel.textColor"];

⑤修改放大镜图标

UITextField *searchField = [searchBar valueForKey:@"_searchField"];
UIImageView *iconView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"icon_search"]];
iconView.frame = CGRectMake(, ,  , );
searchField.leftView = iconView;