如何正确订购NSDrray的NSDrray尊重年，月和日订单？

Question

我有这个返回NSArray日期的方法。问题是，当显示图表时，如果日期具有不同的年份，则日期的顺序不正确。

例如，如果有这些日期：12/25/13，01/18 / 14,13 / 28 / 13,02 / 22/14;该方法将返回如下：01/18 / 14,02 / 22 / 14,12 / 25 / 13,12 / 28/13。

我需要先按照年份订单，然后是月份，然后是一天订购日期。所以最终的数组应该是这样的：12/25/13，12/28/13，01/18/14，02/22/14。

所以任何人都可以指出代码有什么问题？

- (NSArray *)graphViewSortedMonths:(SimpleStockView *)graphView {


NSCalendar *calendar = [NSCalendar currentCalendar];
NSArray *closingDates = [[DailyTradeInfoSource dailyTradeInfos] valueForKeyPath:@"tradingDate"];
//NSLog(@"%@", closingDates);

__weak NSCountedSet *months = [NSCountedSet set];
[closingDates enumerateObjectsUsingBlock:^(id closingDate, NSUInteger index, BOOL *stop) {
    [months addObject:[calendar components:NSMonthCalendarUnit fromDate:closingDate]];
}];
//NSLog(@"%@", months);

NSSortDescriptor *descriptor = [NSSortDescriptor sortDescriptorWithKey:@"month" ascending:YES];
NSArray *descriptors = [NSArray arrayWithObject:descriptor];
NSLog(@"Months %@", [months sortedArrayUsingDescriptors:descriptors]);

return [months sortedArrayUsingDescriptors:descriptors];

}

这是我在NSLog时得到的：

014-03-24 04:10:48.697 SimpleStocks[6343:60b] Months (
"<NSDateComponents: 0x8c34af0>\n    Month: 1\n    Leap month: no",
"<NSDateComponents: 0x8c34c50>\n    Month: 2\n    Leap month: no",
"<NSDateComponents: 0x8c34cb0>\n    Month: 3\n    Leap month: no",
"<NSDateComponents: 0x8c349d0>\n    Month: 12\n    Leap month: no"
)

它应该是：

014-03-24 04:10:48.697 SimpleStocks[6343:60b] Months (
"<NSDateComponents: 0x8c349d0>\n    Month: 12\n    Leap month: no"
"<NSDateComponents: 0x8c34af0>\n    Month: 1\n    Leap month: no",
"<NSDateComponents: 0x8c34c50>\n    Month: 2\n    Leap month: no",
"<NSDateComponents: 0x8c34cb0>\n    Month: 3\n    Leap month: no",
)

这就是我得到的：

这是更正后的代码：

Answer 1

我认为问题在于您只从日期数组中提取月份DateComponents。如果您只按月份排序，它们将按您所看到的顺序排列：1,2,3,12。

我认为，您想要提取月份和年份，然后按年份排序，然后按月份排序：

- (NSArray *)graphViewSortedMonths:(SimpleStockView *)graphView 
{
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSArray *closingDates = [[DailyTradeInfoSource dailyTradeInfos] valueForKeyPath:@"tradingDate"];

    NSCountedSet *monthsAndYears = [NSCountedSet set];
    [closingDates enumerateObjectsUsingBlock:^(id closingDate, NSUInteger index, BOOL *stop) {
        [monthsAndYears addObject:[calendar components:NSMonthCalendarUnit|NSYearCalendarUnit fromDate:closingDate]];
    }];

    NSSortDescriptor *monthDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"month" ascending:YES];
    NSSortDescriptor *yearDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"year" ascending:YES];
    NSArray *descriptors = @[ yearDescriptor, monthDescriptor ];

    NSArray *result = [monthsAndYears sortedArrayUsingDescriptors:descriptors];
    NSLog(@"Months %@", [result valueForKeyPath:@"month"]);

    return result;
}

Answer 2

如果您有日期对象数组，那么您可以使用如下所示。

   - (NSMutableArray *)graphViewSortedMonths:(SimpleStockView *)graphView {
        NSMutableArray *dateObjects =  [NSMutableArray alloc] init];


    NSArray *closingDates = [[DailyTradeInfoSource dailyTradeInfos] valueForKeyPath:@"tradingDate"];

    [closingDates enumerateObjectsUsingBlock:^(id closingDate, NSUInteger index, BOOL *stop) {
        [dateObjects addObject:closingDate];
    }];
    NSLog(@"LOG:%@", dateObjects);
    [dateObjects sortUsingComparator:^NSComparisonResult(id obj1, id obj2)
       {
                return ([obj1 compare:obj2] == NSOrderedAscending);
        }];

NSCalendar *calendar = [NSCalendar currentCalendar];

    NSMutableArray *months =  [NSMutableArray alloc] init];
    for(NSDate *obj in dateObjects){
        [months addObject:[calendar components:NSMonthCalendarUnit fromDate:obj]];
    }
            return months;
        }