UIStepper valueChanged.

Question

I'm making an iphone app and I have met a problem..

I'm making sub views which contains labels and a UIStepper..

They are made by a for loop like so:

//subView to contain one ticket
    UIView *ticketTypeView = [[UIView alloc]initWithFrame:CGRectMake(10, y, 1000, 60)];
    if(ticketCount%2){
    ticketTypeView.backgroundColor = [UIColor lightGrayColor];
    }

    [self.view addSubview:ticketTypeView];

    //label for ticket type name
    UILabel *ticketType = [[UILabel alloc]initWithFrame:CGRectMake(10, 3, 500, 50)];
    [ticketType setText:string];
    [ticketType setFont:[UIFont fontWithName:@"Helvetica neue" size:20.0]];
    [ticketTypeView addSubview:ticketType];


    //UIStepper for ticket amount
    UIStepper *stepper = [[UIStepper alloc]initWithFrame:CGRectMake(500, 16, 0, 0)];
    stepper.transform = CGAffineTransformMakeScale(1.2, 1.2);
    [ticketTypeView addSubview:stepper];

    //label for price pr. ticket
    UILabel *pricePrTicket = [[UILabel alloc]initWithFrame:CGRectMake(620, 5, 100, 50)];
    [pricePrTicket setText:@"1000.00 Kr."];
    [ticketTypeView addSubview:pricePrTicket];

    //totalPrice label
    UILabel *totalTypePrice = [[UILabel alloc]initWithFrame:CGRectMake(900, 5, 100, 50)];
    [totalTypePrice setText:@"0.00 Kr."];
    [ticketTypeView addSubview:totalTypePrice];

Now.. How do I add a IBAction valueChanged for my UIStepper? the stepper is supposed to take the count, multiply it by the pricePrTicket and display it in the totalPrice label..

Any help or hint will be much appreciated :)

Answer 1

You'll need to assign unique tag to all your subviews of ticketTypeView (each should be unique) then follow @thedjnivek answer. When you get call - (void) stepperChanged:(UIStepper*)theStepper method, get totalPrice label object like this,

UILabel *ticketprice = (UILabel *)[theStepper.superview viewWithTag:kTagPriceTicket];

check if label object is not nil,

if(ticketprice) {
   ticketprice.text = theStepper.value * pricePrTicket;
}

In your for loop where you're creating ticketTypeView and other labels.

Your label tag should be unique for labels and the same for individual ticketTypeView views.

Create tags like this (you can give any integer for tags),

#define kTagTicketType 110
#define kTagPriceTicket 111
#define kTagTotalTypePrice 112

...
...
...

[ticketType setTag:kTagTicketType]; //NOTE this

[pricePrTicket setTag:kTagPriceTicket]; //NOTE this

[totalTypePrice setTag:kTagTotalTypePrice]; //NOTE this

Write above lines before adding each of the label.

Answer 2

You have to set the target with addTarget:action: like this :

[stepper addTarget:self action:@selector(stepperChanged:) forControlEvents:UIControlEventValueChanged];

- (void) stepperChanged:(UIStepper*)theStepper{
    //This method would be called on UIControlEventsValueChanged
}

I hope that can help you ;)