我在做一个售票的ipad应用,想减去的时候遇到了问题..
UI是这样制作的:
for(NSString *string in ticketArray){
float y = 60*ticketCount+spaceFloat;
//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);
[stepper addTarget:self action:@selector(chanegestep:) forControlEvents:UIControlEventValueChanged];
stepper.maximumValue = 100;
stepper.minimumValue = 0;
[ticketTypeView addSubview:stepper];
//label for price pr. ticket
UILabel *pricePrTicket = [[UILabel alloc]initWithFrame:CGRectMake(620, 5, 100, 50)];
[pricePrTicket setText:@"1000.50"];
pricePrTicket.tag = kTagPriceTicket;
[ticketTypeView addSubview:pricePrTicket];
//totalPrice label
UILabel *totalTypePrice = [[UILabel alloc]initWithFrame:CGRectMake(900, 5, 100, 50)];
[totalTypePrice setText:@"0.00 Kr."];
totalTypePrice.tag = kTagTotalTypePrice;
[ticketTypeView addSubview:totalTypePrice];
ticketCount++;
}
我的 ValueChanged 方法:
- (IBAction) chanegestep:(UIStepper *)sender {
double va = [sender value];
NSLog(@"stepper pressed");
//get the 2 labels for the price and for displaying price
UILabel *ticketprice = (UILabel *)[sender.superview viewWithTag:kTagPriceTicket];
UILabel *totalPrice = (UILabel *)[sender.superview viewWithTag:kTagTotalTypePrice];
double price = [ticketprice.text doubleValue];
//calc the total from that one ticet type
double totalDisplayed = va*price;
//add to the complete sales amount
completeSalesAmount += totalDisplayed;
NSLog(@"%.02f",completeSalesAmount);
if(ticketprice){
totalPrice.text = [[NSString alloc]initWithFormat:@"%.02fKr.",totalDisplayed];
}
//activate btnContinue
if(completeSalesAmount!=0){
[btnContinue setEnabled:YES];
}
//[ setText:[NSString stringWithFormat:@"%d", (int)va]];
我的问题:将数字相加效果很好,但是当按下步进器上的“-”时,我必须以某种方式检测到它,并从 totalSalesAmount 中减去给定票的价格..
感谢任何帮助。
问候,即将到来的 IOS 开发者 xD
编辑:
每次调用 valueChanged 时都会计算 completedSalesAmount..
假设我有 2 种票证类型,每种票证类型有 1 个选择。
ticket1 - price 10$ - amount 1, total 10$ (10*1)
completeSalesAmount - 0 += (10*1) = 10$
ticket2 - price 10$ - amount 1, total 10$ (10*1)
completeSalesAmount - 10 += (10*1) = 20$
现在在 ticket1 上按下“-”
ticket1 - price 10$ - amount 0, total 0$ (10*0)
completeSalesAmount += 0...
最佳答案
问题是您不知道按下了步进器上的哪个按钮。你可以做的是像这篇文章建议的那样将你的 UIStepper 子类化:
UIStepper. Find out whether incremented or decremented
否则你可以创建一个函数来计算每个 UIStepper 的 completeSalesAmount
,你需要将你的 UIStepper 包装器放在一个数组中:
NSMutableArray *fullSteppers = [NSMutableArray arrayWithCapacity:[ticketArray count]];
for(NSString *string in ticketArray){
...
stepper.tag = kTagStepper;
[fullSteppers addObject:ticketTypeView];
...
}
- (void)updateCompleteSalesAmount{
completeSalesAmount = 0;
for(UIView *fullStepper in fullSteppers){
UILabel *ticketprice = (UILabel *)[fullStepper viewWithTag:kTagPriceTicket];
UILabel *totalPrice = (UILabel *)[fullStepper viewWithTag:kTagTotalTypePrice];
double price = [ticketprice.text doubleValue];
UIStepper *stepper = (UIStepper *)[fullStepper viewWithTag:kTagStepper];
completeSalesAmount += stepper.value * price;
}
}
只需在您的 changestep 方法中调用更新函数:
- (IBAction) chanegestep:(UIStepper *)sender {
....
[self updateCompleteSalesAmount];
}
关于IOS 从以编程方式制作的标签和步进器中减去,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/24135771/