Question

My app is a converter with a multicomponent picker wheel. It is made for converting some variables. The numbers you can see is just for testing, nothing important really.

- (void)viewDidLoad
{
  [super viewDidLoad];
  _convertFrom = @[@"One (1)", @"Two (2)",
  @"Three (3)", @"Four (4)", @"Five (5)"];

  _convertRates = @[ @1.0f, @2.0f, @3.0f,
  @4.0f, @5.0f];

  _convertTo = @[@"One (1)", @"Two (2)",
  @"Three (3)", @"Four (4)", @"Five (5)"];

_convertRates = @[ @1.0f, @2.0f, @3.0f,
@4.0f, @5.0f];

}

I have a small problem with the numbers that is displayed when i test the app in the iOS 6 simulator. As you can see here:

https://i.stack.imgur.com/Rn8Hg.jpg

When i try to go down the list, the numbers change. But the value of them does not.
If someone has got the time to check it out and maybe find a solution it would be very helpful:)

here is the rest of the code that might be important in this case:

#pragma mark -
#pragma mark PickerView DataSource

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

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:    (NSInteger)component
{
if (component == 0)  {
    return [_convertFrom count];
}
return [_convertTo count];
}


- (NSString *) pickerView: (UIPickerView *)pickerView
          titleForRow:(NSInteger)row
         forComponent:(NSInteger)component
{
if (component == 0) {
    return [_convertFrom objectAtIndex:[pickerView selectedRowInComponent:0]];
}
return [_convertTo objectAtIndex:[pickerView selectedRowInComponent:1]];
}




#pragma mark -
#pragma mark PickerView Delegate
-(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row
  inComponent:(NSInteger)component
{
    float convertFrom = [[_convertRates objectAtIndex:[pickerView  selectedRowInComponent:0]] floatValue];
float convertTo = [[_convertRates objectAtIndex:[pickerView selectedRowInComponent:1]] floatValue];
float input = [dollarText.text floatValue];
float to = convertTo;
float from = convertFrom;
float dollars = input;
float result = to * from * dollars;
float mtpaTilMtpaFloat = dollars * 1;
NSString *resultString = [[NSString alloc] initWithFormat:
                          @"result = %.2f *  %.2f = %.2f", from, to, result];
resultLabel.text = resultString;

NSString *mtpaTilmtpa = [[NSString alloc ] initWithFormat:
                           @" %.2f MTPA = %.2f MTPA", dollars, mtpaTilMtpaFloat];



if (from == 1, to == 1) { resultLabel.text = mtpaTilmtpa;
}

And of course, tell me if I need to display more of the code so you can understand it. its my first time using this website btw:)

Answer 1

don’t use selectedRowInComponent. You don’t wan’t to display the value that is selected in all your rows. Just use row

- (NSString *) pickerView: (UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component
{
    if (component == 0) {
        return [_convertFrom objectAtIndex:row];
    }
    return [_convertTo objectAtIndex:row];
}