Question

in one of my view controllers I want to use multiple pickers.

Header file:

@interface MyTableController : TTTableViewController <UIActionSheetDelegate, UIPickerViewDataSource, UIPickerViewDelegate>{

    IBOutlet UIPickerView *picker1;
    IBOutlet UIPickerView *picker2;

    NSMutableArray *list1;
    NSMutableArray *list2;
}

@property(nonatomic,retain) UIPickerView *picker1, *picker2;

-(IBAction)togglePickerView1;
-(IBAction)togglePickerView2;

@end

Implementation file:

@implementation MyTableController

@synthesize picker1, picker2;

int row_index1 = 0;
int row_index2 = 0;

- (void)locationPicker:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent: (NSInteger)component
{
    if([pickerView isEqual: picker1]){
        row_index1 = row;
    }

    if([pickerView isEqual: picker2]){
        row_index2 = row;
    }
}

-(NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView{

    if([pickerView isEqual: picker1]){
        return 1;
    }

    if([pickerView isEqual: picker2]){
        return 1;
    }         
    return 0;
}

- (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component{
    if([pickerView isEqual: picker1]){
        return [list1 count];
    }

    if([pickerView isEqual: picker2]){
        return [list2 count];
    }  
    return 0;
}

- (NSString *)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent: (NSInteger)component{
    return [list objectAtIndex:row];
    if([pickerView isEqual: picker1]){
        return [list1 objectAtIndex:row];
    }

    if([pickerView isEqual: picker2]){
        return [list2 objectAtIndex:row];
    }

    return nil;
}

-(void)actionSheet:(UIActionSheet *)actionSheet didDismissWithButtonIndex:(NSInteger)buttonIndex {  

}

- (void)willPresentActionSheet:(UIActionSheet *)actionSheet {

    if (actionSheet.tag == 111) {
        picker1 = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 40, 320, 216)];
        picker1.showsSelectionIndicator = YES;
        picker1.dataSource = self;
        picker1.delegate = self;  

        //Add picker to action sheet
        [actionSheet addSubview:picker1];
        [picker1 release];
    }else if(actionSheet.tag == 222){
        picker2 = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 40, 320, 216)];
        picker2.showsSelectionIndicator = YES;
        picker2.dataSource = self;
        picker2.delegate = self;

        //Add picker to action sheet
        [actionSheet addSubview:picker2];
        [picker2 release];
    }

    //Gets an array af all of the subviews of our actionSheet
    NSArray *subviews = [actionSheet subviews];

    [[subviews objectAtIndex:1] setFrame:CGRectMake(20, 266, 280, 46)]; 
    [[subviews objectAtIndex:2] setFrame:CGRectMake(20, 317, 280, 46)];
}

-(IBAction)togglePickerView1{
    UIActionSheet *asheet = [[UIActionSheet alloc] initWithTitle:NSLocalizedString(@"FLT", nil) delegate:self cancelButtonTitle:NSLocalizedString(@"CANCEL", nil) destructiveButtonTitle:nil otherButtonTitles:NSLocalizedString(@"PICK", nil), nil];
    [asheet setTag:111];
    [asheet showInView:[self.view superview]]; //note: in most cases this would be just self.view, but because I was doing this in a tabBar Application, I use the superview.
    [asheet setFrame:CGRectMake(0, 117, 320, 383)];
    [asheet release];   
}

-(IBAction)togglePickerView2{
    //...  
    [asheet setTag:222];
    //...
}

- (void)loadView {
    [super loadView];
}

-(void)viewDidLoad{

    UIBarButtonItem *item1 = [[UIBarButtonItem alloc] initWithTitle:@"Button1" style:UIBarButtonItemStyleBordered target:self action:@selector(togglePickerView1)];

    UIBarButtonItem *item2 = [[UIBarButtonItem alloc] initWithTitle:@"Button2" style:UIBarButtonItemStyleBordered target:self action:@selector(togglePickerView2)];


    NSArray *myToolbarItems = [[NSArray alloc] initWithObjects: item1, item2, nil];                 

    [self setToolbarItems: myToolbarItems];
    [myToolbarItems release];

    list1 = [[NSMutableArray alloc] init];

    [list1 addObject:@"--"];
    [list1 addObject:@"Test1"];

    list2 = [[NSMutableArray alloc] init];

    [list2 addObject:@"--"];
    [list2 addObject:@"Test2"];
}


@end

My problem is that no matter which button I hit, it is always the picker1 that is triggered. Any ideas where the problem is?

Answer 1

You are successfully creating two different pickers, and showing the correct one each time.

The problem is, each picker has the same data in it.

The first line in your data source titleForRow... method is this:

return [list objectAtIndex:row];

This ends execution of your data source method by returning a value, so both pickers will always show the same data, regardless of the rest of your code. list isn’t declared anywhere in your code above so I’m not sure what you are actually seeing on the screen.

I have built a sample project using your code above and confirmed that this is the issue. Removing that line gives you two different pickers, with the different content in each one.