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

-(void)searchBarTextDidBeginEditing:(UISearchBar *)searchBar{    searchBar.showsCancelButton = YES;    for(UIView *view in  [[[searchBar subviews] objectAtIndex:0] 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:14];        }    }}

UIView *backView = [[UIView alloc]initWithFrame:searchBar.bounds];backView.backgroundColor = [UIColor colorWithRed:37/255.0 green:205/255.0 blue:120/255.0 alpha:1];[searchBar insertSubview:backView atIndex:1];

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

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

UITextField *searchField = [searchBar valueForKey:@"_searchField"];UIImageView *iconView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"icon_search"]];iconView.frame = CGRectMake(0, 0, 15 , 15);searchField.leftView = iconView;