9

我想获取当月的所有记录，所以我为该月的第一个日期和该月的最后一天堆叠了两个谓词。由于我使用 CoreData，因此日期实际上存储为 NSTimeInterval。

NSCalendar *calendar = [NSCalendar currentCalendar];

//Get beginning of current month
NSDateComponents *beginningOfCurrentMonthComponents = [calendar components:(NSEraCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit) fromDate:date];
[beginningOfCurrentMonthComponents setDay:1];
NSDate *beginningOfCurrentMonthDate = [calendar dateFromComponents:beginningOfCurrentMonthComponents];

//Set a single month to be added to the current month
NSDateComponents *oneMonth = [[NSDateComponents alloc] init];
[oneMonth setMonth:1];

//determine the last day of this month
NSDate *beginningOfNextMonthDate = [calendar dateByAddingComponents:oneMonth toDate:beginningOfCurrentMonthDate options:0];

NSMutableArray *parr = [NSMutableArray array];
[parr addObject:[NSPredicate predicateWithFormat:@"recordDate >= %d", [beginningOfCurrentMonthDate timeIntervalSince1970]]];
[parr addObject:[NSPredicate predicateWithFormat:@"recordDate < %d", [beginningOfNextMonthDate timeIntervalSince1970]]];

//Give me everything from beginning of this month until end of this month
NSPredicate *predicate = [NSCompoundPredicate andPredicateWithSubpredicates:parr];

return [allRecords filteredArrayUsingPredicate:predicate];

返回过滤后的数组后，它会崩溃并显示以下错误消息：

2013-10-25 19:09:39.702 [3556:a0b] -[__NSCFNumber timeIntervalSinceReferenceDate]: unrecognized selector sent to instance 0x8911440
2013-10-25 19:09:39.704 [3556:a0b] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFNumber timeIntervalSinceReferenceDate]: unrecognized selector sent to instance 0x8911440'
*** First throw call stack:
(
    0   CoreFoundation                      0x01aa85e4 __exceptionPreprocess + 180
    1   libobjc.A.dylib                     0x0182b8b6 objc_exception_throw + 44
    2   CoreFoundation                      0x01b45903 -[NSObject(NSObject) doesNotRecognizeSelector:] + 275
    3   CoreFoundation                      0x01a9890b ___forwarding___ + 1019
    4   CoreFoundation                      0x01a984ee _CF_forwarding_prep_0 + 14
    5   CoreFoundation                      0x01a7e3e3 -[NSDate compare:] + 67
    6   Foundation                          0x014194fe -[NSComparisonPredicateOperator performPrimitiveOperationUsingObject:andObject:] + 408
    7   Foundation                          0x014b03de -[NSPredicateOperator performOperationUsingObject:andObject:] + 306
    8   Foundation                          0x014b016c -[NSComparisonPredicate evaluateWithObject:substitutionVariables:] + 347
    9   Foundation                          0x014299b6 -[NSCompoundPredicateOperator evaluatePredicates:withObject:substitutionVariables:] + 240
    10  Foundation                          0x01429845 -[NSCompoundPredicate evaluateWithObject:substitutionVariables:] + 294
    11  Foundation                          0x014b0009 -[NSPredicate evaluateWithObject:] + 48
    12  Foundation                          0x014aff89 _filterObjectsUsingPredicate + 418
    13  Foundation                          0x014afd42 -[NSArray(NSPredicateSupport) filteredArrayUsingPredicate:] + 328

我还使用此循环来指示 recordDate 确实存在于数组中：

for (FTRecord *r in allRecords) {
    NSLog(@"%f", [r recordDate]);
}

2013-10-25 19:09:35.860 [3556:a0b] 1380582000.000000
2013-10-25 19:09:36.556 [3556:a0b] 1380754800.000000
4

3 回答 3

16

您在创建托管对象子类时选择了“使用原始数据类型的标量属性”选项，以便在 NSTimeInterval类中表示 recordDate FTRecord。

但是在像 一样的谓词"recordDate >= 123.45"中，左侧存储为 a NSKeyPathExpression，valueForKeyPath:@"recordDate"用于访问返回NSDate对象的属性。该谓词的右侧存储为NSConstantValueExpression 对NSNumber对象的引用。因此，将 anNSDate与 an 进行比较NSNumber，这正是您得到的异常。

要解决此问题，您必须将该属性与NSDate （@rmaddy 最初建议的）进行比较：

[parr addObject:[NSPredicate predicateWithFormat:@"recordDate >= %@", beginningOfCurrentMonthDate]];
[parr addObject:[NSPredicate predicateWithFormat:@"recordDate < %@", beginningOfNextMonthDate]];
NSPredicate *predicate = [NSCompoundPredicate andPredicateWithSubpredicates:parr];

我对此进行了测试，它似乎产生了预期的结果。

但是请注意，Core Data 使用timeIntervalSinceReferenceDateand dateWithTimeIntervalSinceReferenceDate在标量值和 之间进行转换NSDate，而不是timeIntervalSince1970.

于 2013-10-25T18:45:51.653 回答
2

对于 Swift 3 中的解决方案：

let date = NSDate()
let calender = NSCalendar.current
var beginningOfCurrentMonthComponents = calender.dateComponents([.year, .month, .day], from: date as Date)

beginningOfCurrentMonthComponents.day = 1

let beginningOfCurrentMonthDate = calender.date(from: beginningOfCurrentMonthComponents)
let beginningOfNextMonth = calender.date(byAdding: .month, value: 1, to: beginningOfCurrentMonthDate!)

let pred1 = NSPredicate(format: "date >= %@", beginningOfCurrentMonthDate! as NSDate)
let pred2 = NSPredicate(format: "date < %@", beginningOfNextMonth! as NSDate)

let predicate = NSCompoundPredicate.init(andPredicateWithSubpredicates: [pred1, pred2])
于 2016-09-21T07:44:53.820 回答
0

将在谓词本身中添加 timeIntervalSince1970 。它会

NSPredicate* 谓词 = PREDICATE(@"(lastUpdatedTime == nil OR lastUpdatedTime.timeIntervalSince1970 <= %f)",currentDate.timeIntervalSince1970);

于 2015-11-27T00:22:31.747 回答