Question

这里我在顶部使用了一个标签来显示今年的月份。而且我还有6个标签，它会显示今天的日期，例如31dec到1月5日。这是代码：

这将显示下一个5日期的今天日期

 NSArray *labelArray = @[flabel, slabel, tlabel, folabel, fivlabel,sixlabel];
 NSDate *today = [NSDate date];
 NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
 NSCalendar *calendar = [NSCalendar currentCalendar];
 dateFormatter.dateFormat = @"ddMMM";
 for (NSInteger i = 0; i < 6; ++i) {
     NSDate *nextDate = [calendar dateByAddingUnit:NSCalendarUnitDay value:i toDate:today options:nil];
     UILabel *label = (UILabel *)labelArray[i];
     label.text = [dateFormatter stringFromDate:nextDate];
 }

这将显示当前年份

// show the present month
    NSDate *date = [NSDate date];

   // NSDateFormatter *date = [[NSDateFormatter alloc] init];
    dateFormatter.dateFormat=@"MMMM";
    NSString * monthString = [[dateFormatter stringFromDate:date] capitalizedString];
    dateFormatter.dateFormat=@"yyyy";
    NSString * yearString = [[dateFormatter stringFromDate:date] capitalizedString];
    dateLabel.text = [NSString stringWithFormat:@"%@ ,%@",monthString,yearString];

重要的：

我需要的是我需要显示如下图像：

当前日期应显示在最后，并且应显示之前的前5个日期。
我左右两个按钮。当用户按下右键时，比如现在说它的31Dec。当用户按下右键时，它应该变为1Jan并且应该显示从1月1日开始的前5个日期。并且月份.label应该自动更改为2016年1月。如下图所示：

两个按钮动作：

- (IBAction)calRight:(id)sender {

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"MMMM,yyyy"];
    NSDate *tempDate = [dateFormat dateFromString:dateLabel.text];

    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    [dateComponents setMonth:1];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *newDate = [calendar dateByAddingComponents:dateComponents toDate:tempDate options:0];

    dateLabel.text = [dateFormat stringFromDate:newDate];
}

- (IBAction)calLeft:(id)sender {

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"MMMM,yyyy"];
    NSDate *tempDate = [dateFormat dateFromString:dateLabel.text];

    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    [dateComponents setMonth:-1];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *newDate = [calendar dateByAddingComponents:dateComponents toDate:tempDate options:0];

    dateLabel.text = [dateFormat stringFromDate:newDate];
}

这个代码我只是为了改变了我试过的月份。但是没有改变我的日期标签。

请在代码中解释我。

完整编辑：

- (void)viewDidLoad {
    [super viewDidLoad];

    NSDate *firstLabelDate = [NSDate date]; //make it class variable

    NSDate *lastLabelDate = [NSDate date]; //make it class variable

    NSArray *labelArray = @[flabel, slabel, tlabel, folabel, fivlabel,sixlabel]; //make it class variable

    [self updateDateLabelsGoingForward:YES andFromDay:self.lastLabelDate];
}


- (IBAction)calRight:(id)sender {

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"MMMM,yyyy"];
    NSDate *tempDate = [dateFormat dateFromString:dateLabel.text];

    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    [dateComponents setMonth:1];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *newDate = [calendar dateByAddingComponents:dateComponents toDate:tempDate options:0];

    dateLabel.text = [dateFormat stringFromDate:newDate];
    [self updateDateLabelsGoingForward:YES andFromDay:self.lastLabelDate];
}

- (IBAction)calLeft:(id)sender {

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"MMMM,yyyy"];
    NSDate *tempDate = [dateFormat dateFromString:dateLabel.text];

    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    [dateComponents setMonth:-1];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *newDate = [calendar dateByAddingComponents:dateComponents toDate:tempDate options:0];

    dateLabel.text = [dateFormat stringFromDate:newDate];
    [self updateDateLabelsGoingForward:NO andFromDay:self.firstLabelDate];
}

- (void)updateDateLabelsGoingForward:(BOOL) goForward andFromDay:(NSDate*) dayFrom {

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    dateFormatter.dateFormat = @"ddMMM";

    for (NSInteger i = 0; i < 6; ++i) {
        int dateToBeModified = goForward?1:-1;
        NSDate *nextDate = [calendar dateByAddingUnit:NSCalendarUnitDay value:dateToBeModified toDate:dayFrom options:nil];
        UILabel *label = (UILabel *)self.labelArray[i];
        label.text = [dateFormatter stringFromDate:nextDate];

        if(i==5){
            self.lastLabelDate = nextDate;
        }
        if(i==0){
            self.firstLabelDate = nextDate;
        }
    }
}

Answer 1

首先创建一个数组，存储日期为6天...... NSArray *dates。
然后在[NSDate date]使用dates[0]对其进行初始化。
使用NSDateComponents并减去日期组件，并将前5天存储在dates[1.....4]的数组中。
点击按钮，您可以递增或递减整个数组，并再次显示所有日期....

Answer 2

全局定义一个Date对象NSDate *firstdate;并在viewDidLoad中指定其值firstdate = [NSDate date];

现在使用以下方法显示您的日期＆amp;月从viewDidLoad [self dateChange];

调用此方法

-(void)dateChange
{
    NSArray *labelArray = @[flabel, slabel, tlabel, folabel, fivlabel,sixlabel];
    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    dateFormatter.dateFormat = @"ddMMM";
    for (NSInteger i = 0; i < 6; ++i) {
        NSDate *nextDate = [calendar dateByAddingUnit:NSCalendarUnitDay value:i toDate:firstdate options:nil];
        UILabel *label = (UILabel *)labelArray[i];
        label.text = [dateFormatter stringFromDate:nextDate];
        if (i==5) {
            dateFormatter.dateFormat=@"MMMM";
            NSString * monthString = [[dateFormatter stringFromDate:nextDate] capitalizedString];
            dateFormatter.dateFormat=@"yyyy";
            NSString * yearString = [[dateFormatter stringFromDate:nextDate] capitalizedString];
            dateLabel.text = [NSString stringWithFormat:@"%@ ,%@",monthString,yearString];
        }
    }

}

现在将你的calRight和calLeft设置为低于标准

- (IBAction)calRight:(id)sender {
firstdate = [NSDate dateWithTimeInterval:86400 sinceDate:firstdate];
[self dateChange];
}

- (IBAction)calLeft:(id)sender {
    firstdate = [NSDate dateWithTimeInterval:-86400 sinceDate:firstdate];
    [self dateChange];
}

Answer 3

非常简单，实际上你几乎就在那里，再添加一个变量来保存最后一个标签显示的最后一个日期，让我们不要因为通过NSDateFormatter等长路线从标签中取出日期而搞得一团糟！

 NSDate *firstLabelDate = [NSDate date]; //make it class variable

 NSDate *lastLabelDate = [NSDate date]; //make it class variable

 NSArray *labelArray = @[flabel, slabel, tlabel, folabel, fivlabel,sixlabel]; //make it class variable

[self updateDateLabelsGoingForward:YES andFromDay:self.lastLabelDate];

您的按钮操作应修改如下，

- (IBAction)calRight:(id)sender {

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"MMMM,yyyy"];
    NSDate *tempDate = [dateFormat dateFromString:dateLabel.text];

    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    [dateComponents setMonth:1];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *newDate = [calendar dateByAddingComponents:dateComponents toDate:tempDate options:0];

    dateLabel.text = [dateFormat stringFromDate:newDate];
    [self updateDateLabelsGoingForward:YES andFromDay:self.lastLabelDate];
}

- (IBAction)calLeft:(id)sender {

    NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
    [dateFormat setDateFormat:@"MMMM,yyyy"];
    NSDate *tempDate = [dateFormat dateFromString:dateLabel.text];

    NSDateComponents *dateComponents = [[NSDateComponents alloc] init];
    [dateComponents setMonth:-1];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDate *newDate = [calendar dateByAddingComponents:dateComponents toDate:tempDate options:0];

    dateLabel.text = [dateFormat stringFromDate:newDate];
    [self updateDateLabelsGoingForward:NO andFromDay:self.firstLabelDate]

}

添加常用方法以重新加载日期标签。

- (void)updateDateLabelsGoingForward:(BOOL) goForward andFromDay:(NSDate*) dayFrom {

    NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
    NSCalendar *calendar = [NSCalendar currentCalendar];
    dateFormatter.dateFormat = @"ddMMM";

    for (NSInteger i = 0; i < 6; ++i) {
        int dateToBeModified = goForward?(1*i):(-1*i);
        NSDate *nextDate = [calendar dateByAddingUnit:NSCalendarUnitDay value:dateToBeModified toDate:dayFrom options:nil];
        UILabel *label = (UILabel *)self.labelArray[i];
        label.text = [dateFormatter stringFromDate:nextDate];

        if(i==5){
            self.lastLabelDate = nextDate;
        }
        if(i==0){
            self.firstLabelDate = nextDate;
        }
    }
}

希望这会有所帮助，从长远来看，这可以帮助你。

显示日历动态，同时显示月份

3 个答案: