iphone - 如何通过单击按钮更改数字时钟的时间格式？

Question

我有一个数字时钟，我通过 0.png 到 9.png 的图像显示它。数字时钟显示正常，但问题是其时间格式为 24 小时制。

我尝试将时钟格式更改为 12 小时制，但它仍然以 24 小时制显示时钟。我怎样才能做到这一点？

这是我的代码:

NSDate *dateShow= [NSDate dateWithTimeIntervalSinceNow:0];
    NSDateFormatter *dateFormat = [[[NSDateFormatter alloc] init] autorelease];
    [dateFormat setTimeStyle:NSDateFormatterNoStyle];
    //[dateFormat setDateFormat:@"hh:mm"];
    /
    //NSString *dateString = [dateFormat stringFromDate:dateShow];


    NSDate * date = [NSDate date];
    NSCalendar * calendar = [[NSCalendar alloc]
                             initWithCalendarIdentifier:NSGregorianCalendar];
    NSDateComponents * components =
    [calendar components:(NSHourCalendarUnit | NSMinuteCalendarUnit) fromDate:date];

    NSInteger hour = [components hour];
    NSInteger minute = [components minute];
    NSInteger firstHourDigit = hour/10;
    NSInteger secondHourDigit = hour%10;
    NSInteger firstMinuteDigit = minute/10;
    NSInteger secondMinuteDigit = minute%10;

    int res=0;
    for(int i=0;i<4;i++)
         {

             if(i==0)
                res = firstHourDigit;
         else if(i==1)
                 res = secondHourDigit;
            else if (i==2)
                 res = firstMinuteDigit;
             else 
                 res = secondMinuteDigit;

                 switch (res) {

                     case 0:
                     str_imageName=@"0.png";
                     break;
                     case 1:
                     str_imageName=@"1.png";
                     break;
                    case 2:
                     str_imageName=@"2.png";
                     break;
                     case 3:
                     str_imageName=@"3.png";
                     break;
                    case 4:
                    str_imageName=@"4.png";
                    break;
                    case 5:
                    str_imageName=@"5.png";
                    break;
                    case 6:
                     str_imageName=@"6.png";
                    break;
                    case 7:
                    str_imageName=@"7.png";
                    break;
                    case 8:
                    str_imageName=@"8.png";
                    break;
                    case 9:
                    str_imageName=@"9.png";
                     break;

                    default:
                    break;
                }
            if(i==0)
                [minfirstImage setImage:[UIImage imageNamed:str_imageName]];
            else if(i==1)
                [minsecondImage setImage:[UIImage imageNamed:str_imageName]];
            else if (i==2)
                [secfirstImage setImage:[UIImage imageNamed:str_imageName]];
            else 
                [secSecondImage setImage:[UIImage imageNamed:str_imageName]];



        }

Answer 1

对您的时间使用模数...

value % 12

所以 9 % 12 = 9, 14 % 12 = 2.... 等等