Question

我有一个简单的模型，代表日餐和培训课程。我遇到了从CoreData获取Day的问题。我收到以下错误。

2011-11-14 11:41:44.999 CalorificCounter[21002:fb03] -[__NSCFString timeIntervalSinceReferenceDate]: unrecognized selector sent to instance 0x6a6d1a0
2011-11-14 11:41:45.001 CalorificCounter[21002:fb03] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFString timeIntervalSinceReferenceDate]: unrecognized selector sent to instance 0x6a6d1a0'

代码

-(Day *)getDayForDate:(NSDate *)date
{
    Day *day;
    date = [self dateAtStartOfDay:date];

    NSFetchRequest *request = [[NSFetchRequest alloc]init];
    NSEntityDescription *entity = [NSEntityDescription entityForName:@"Day" 
                                        inManagedObjectContext:[self managedObjectContext]];

    //Find the object that matches the given date from a predicate
    NSPredicate *predicate = [NSPredicate predicateWithFormat:@"date == \"%@\"",date];


    [request setEntity:entity];
    [request setPredicate:predicate];

    //Try to fetch
    NSError *error;
    NSArray *result = [[self managedObjectContext] executeFetchRequest:request 
                                                             error:&error ] ;

执行获取请求时发生错误。我已经跟踪执行，一切似乎都是正确的类型（至少我从来没有传递过字符串）。提前谢谢。

更新不要将谓词日期放在引号

中

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"date == %@",date];

Answer 1

将字符串分配给日期对象时会发生此问题。检查日期值并返回NSDate对象

核心数据问题和查找日期

1 个答案: