Fixed labels in the selection bar of a UIPickerView

Question

In the clocks application, the timer screen shows a picker (probably a UIPicker in UIDatePickerModeCountDownTimer mode) with some text in the selec

Answer 1

Let's say we want to implement a picker view for selecting distance, there are 2 columns, one for distance, one for unit, which is km. Then we want the second column to be fixed. We can make it through some delegate methods.

- (NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    if (component == 0) {
        return self.distanceItems[row];
    }
    else {
        return @"km";
    }
}

-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{
    return 2;
}

-(NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
    if (component == 0) {
        return [self.distanceItems count];
    }
    else {
    // when it comes to the second column, only one row.
        return 1;
    }
}

Now we have this:

I guess this is the simplest way.