How do you shrink a UIPickerView on the iPhone?

I would like to reduce the height of a UIPickerView in my iPhone app, so that it shows only one row and one column. The height of the picker view should be equal to the height of a row.

I'm using Interface Builder to construct the UIPickerView, but I can't find an easy way to re-size this control.

How do you shrink a UIPickerView?

Actually, you can slightly shrink the whole UIPickerView by applying an affine transform to an enclosing view. For example:

CGSize pickerSize = [pickerView sizeThatFits:CGSizeZero];

pickerTransformView = [[UIView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, pickerSize.width, pickerSize.height)];
pickerTransformView.transform = CGAffineTransformMakeScale(0.75f, 0.75f);

[pickerTransformView addSubview:pickerView];
[self.view addSubview:pickerTransformView];
[pickerTransformView release];

will scale a picker to 75% of its original size by placing it within a containing view and applying a scaling transform to that view. Applying a transform directly to the UIPickerView leads to undesirable drawing artifacts.

However, the kind of resizing you're looking for would be best served by creating a custom control.

It is possible and easy!

Just open the nib file as plain text, then find the picker view and adjust the measures:

<object class="IBUIPickerView" id="783900772">
<reference key="NSNextResponder" ref="191373211"/>
<int key="NSvFlags">292</int>
<string key="NSFrame">{{85, 68}, {150, 116}}</string>

That's all!