Changing UIPickerView row height

In the documentation for the UIPickerView, you have a link to the UIPickerViewDelegate protocol. There is a method that you can implement, pickerView:rowHeightForComponent:.

use this method,provide default as a delegete method.

objective-C

- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component
{
    return 40;
}

In Swift:

func pickerView(pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat 
{   
    return 40
}

for more visit : real world implementation