Question

I am writing code to programmatically create a view. In this view I am creating two UIPickerViews, however, as the title explains, when I go to populate the lists with data, all of the data goes into the second table, and none in the first. I can see where exactly the problem is, but don’t know how to fix it. Here is the code with editing around non-related parts.

in the below section is where i create the pickerview. Essentially I have a large list of data. If i see any occurance of “RadioButton” I create a PickerView. RadioButton can appear more than once and is where my issue lies.

 for(int i = 0; i < [list count]; i++){  
 ...

 else if([input.controlTypeName compare:@"RadioButton"] == NSOrderedSame){
        [radioList addObject:input.sourceText]; 
        radioPicker = [[UIPickerView alloc] initWithFrame:CGRectMake(50, y, 220, 200)];
        radioPicker.delegate = self;
        radioPicker.showsSelectionIndicator = YES;
        [inputsView addSubview:radioPicker];
        y = y+220;

    }

the delegate methods are as follows..

       - (void)pickerView:(UIPickerView *)pickerView didSelectRow: (NSInteger)row inComponent:(NSInteger)component {
// Handle the selection
}

// tell the picker how many rows are available for a given component
- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {

if([pickerView isEqual: radioPicker]){
    return [radioList count];
}




 // tell the picker how many components it will have
- (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
   return 1;
}

 // tell the picker the title for a given component
 - (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {

  if([pickerView isEqual: radioPicker]){
    id myArrayElement = [radioList objectAtIndex:row];
    NSString *title = myArrayElement; 
    NSLog(@"title to fill radio:%@", title); 
    return title;
  }


 }

// tell the picker the width of each row for a given component
- (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component {
int sectionWidth = 200;

   return sectionWidth;
 }

Essentially what seems to be happening is on the 2nd creation of the ‘RadioButton’ ListPicker, the first creation loses the tag ‘radioPicker’ and the line

if([pickerView isEqual: radioPicker]){ 

fails. So all of the data is pushed into the second(and latest) creation. But I don’t know how to have this not happen. Any ideas would be great.

Thanks.

Answer 1

The issue is that you have a single instance variable, radioPicker. It’s fine to have two UIPickerViews and be the delegate of both. However, you need to base the delegate methods on the passed-in value, not the (single) instance variable.

There’s actually no need to have radioPicker. Once you send addSubview:, just autorelease the view (unless you’re using ARC).

In order to distinguish the views, you might want to set the tag property, and use that in things like the titleForRow: delegate method.