如何增加选择器视图(转换的选择器视图)的宽度?

我试图水平滚动选取器视图,这是我的代码。

     CGRect frame = horizontalPickerView.frame;
            frame.size.width = 50;
            frame.size.height = 216;
            frame.origin.x=90;
            frame.origin.y = 200;
            horizontalPickerView.frame = frame;

            horizontalPickerView.transform = CGAffineTransformMakeRotation(3.14159/2); 






- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view{
        UILabel *lbl = [[[UILabel alloc] initWithFrame:CGRectMake(0, 0, 30, 20)] autorelease];
        lbl.transform = CGAffineTransformMakeRotation(-3.14159/2);
        lbl.text = @"hi";
        return lbl;
    }

但问题是,如果我尝试这样做,我无法将选择器视图的宽度更改超过216.0,因为会留下黑色背景。

CorrectImage http://img709.imageshack.us/img709/6982/picture5g.png

现在如果我这样做

CGRect frame = horizontalPickerView.frame;
                frame.size.width = 50;
                frame.size.height = 300;
                frame.origin.x=120;
                frame.origin.y = 200;
                horizontalPickerView.frame = frame;

                horizontalPickerView.transform = CGAffineTransformMakeRotation(3.14159/2);

我明白了 image http://img46.imageshack.us/img46/2792/picture6b.png

我见过像Seelibrity这样的应用程序,其中选择器的宽度适合屏幕。 请帮我解决这个问题好吗?