You're populating your data source incorrectly. You should have a model like this:
contacts : [ { id : "12", name : "Administrator" }, { id : "13", name : "Dude" } ]
After you parse it into the array, in the -pickerView:titleForRow:forComponent:
you'll have to pick an NSDictionary value from. Grab the id value from the dictionary fetched from your data source from the -pickerView:didSelectRow:inComponent:
method.
edit
- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component
{
NSNumber *idNumber = _contacts[row][@"id"];
//perform whatever action you need to with selected contact id
}