Question

I am trying to scroll the picker view horizontally and this is my code.

in viewDidLoad I did this,

     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;
    }

But the problem is I am not able to change the width of picker view more than 216.0 if I try to do this there is a black background left.

CorrectImage http://img709.imageshack.us/img709/6982/picture5g.png this is the correct image

Now if I do this

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);

I get this image http://img46.imageshack.us/img46/2792/picture6b.png

I have seen the apps like Seelibrity in which the picker has the width to fit the screen.
Please help me to get out of this problem?

Answer 1

UIPickerView is very sensitive to changes in height, so directly altering its frame or applying a transform to the UIPickerView leads to rendering artifacts. The only reliable way that I know of for resizing a UIPickerView is to place it within a transparent UIView, then apply a scaling (and rotation, in your case) transform to that holder view.

I provide an example of this in this answer.