Ios 包含的谓词导致的异常

我得到了一个奇怪的例外，我不知道如何找出这里出了什么问题

"Serious application error.  **Exception was caught during Core Data change processing.**  This is usually a bug within an observer of NSManagedObjectContextObjectsDidChangeNotification.  **Can't look for value (552284302) in string (1070635162, 630076961, 690758344, 714304224, 693603903, 650263092, 552284302); value is not a string  with userInfo (null)**"

我的代码如下：

- (NSFetchedResultsController *)fetchedResultsController {

if (_fetchedResultsController != nil) {
    return _fetchedResultsController;
}

NSManagedObjectContext *context =   [ (MyAppDelegate*)[[UIApplication sharedApplication] delegate]managedObjectContext];

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *entity = [NSEntityDescription 
                               entityForName:@"MyEntityName" inManagedObjectContext:context];
[fetchRequest setEntity:entity];

NSSortDescriptor *sort = [[NSSortDescriptor alloc] 
                          initWithKey:@"distance" ascending:YES];
[fetchRequest setSortDescriptors:[NSArray arrayWithObject:sort]];

[fetchRequest setFetchBatchSize:20];

User *user = [[DatabaseHelper sharedInstance] getUserDetails];
NSString *predicteString = [NSString stringWithFormat:@"isPrivate == %@  AND recepientList contains %@", [NSNumber numberWithBool:YES], user.userId];

if(dootType == UnReadDootType){
    predicteString = [predicteString stringByAppendingString:@" AND state = 'NEW' "];
}


NSPredicate *predicate;
if(senderId != nil && [senderId intValue] > 0){
    predicteString = [predicteString stringByAppendingString:@" AND senderId == %@"];

    predicate = [NSPredicate
                 predicateWithFormat:predicteString, senderId];

}else{
    predicate = [NSPredicate
                 predicateWithFormat:predicteString];
}

[fetchRequest setPredicate:predicate];


NSFetchedResultsController *theFetchedResultsController = 
[[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest 
                                    managedObjectContext:context sectionNameKeyPath:nil 
                                               cacheName:@"MyEntityName"];

self.fetchedResultsController = theFetchedResultsController;
_fetchedResultsController.delegate = self;

[sort release];
[fetchRequest release];
[theFetchedResultsController release];

return _fetchedResultsController;    

}

NSFetchRequest记录为：

<NSFetchRequest: 0x362350> (entity: MyEntityName; predicate: (isPrivate == 1 AND recepientList CONTAINS 552284302); sortDescriptors: ((
    "(distance, ascending, compare:)"
)); batch size: 20; type: NSManagedObjectResultType; )

(isPrivate == 1 AND recepientList CONTAINS 552284302)

如你们所见，我使用了一个谓词，比如recepientList包含552284302 对于我的一条记录，recepientList中有1070635162、6300769078344、714304224、693603903、650263092、552284302。我正在recepientList中存储逗号分隔的userId，所以我不确定为什么会出现这种异常。

user.userId被解析为数值而不是字符串。CONTAINS运算符不理解数值

记录为以下内容的谓词：

<NSFetchRequest: 0x362350> (entity: MyEntityName; predicate: (isPrivate == 1 AND recepientList CONTAINS 552284302); sortDescriptors: ((
    "(distance, ascending, compare:)"
)); batch size: 20; type: NSManagedObjectResultType; )

(isPrivate == 1 AND recepientList CONTAINS 552284302)

…应记录为：

(isPrivate == 1 AND recepientList CONTAINS "552284302")

前一个谓词查找数值，而后一个谓词查找字符串。请注意，isPrivate==1中的数字未被引用

如果user.userID是一个NSNumber，那么获取它的字符串值应该可以解决这个问题。尝试：

NSString *predicteString = [NSString stringWithFormat:@"isPrivate == %@  AND recepientList contains %@", [NSNumber numberWithBool:YES], [user.userId stringValue]];

正在将user.userID解析为数值而不是字符串。CONTAINS运算符不理解数值

记录为以下内容的谓词：

<NSFetchRequest: 0x362350> (entity: MyEntityName; predicate: (isPrivate == 1 AND recepientList CONTAINS 552284302); sortDescriptors: ((
    "(distance, ascending, compare:)"
)); batch size: 20; type: NSManagedObjectResultType; )

(isPrivate == 1 AND recepientList CONTAINS 552284302)

…应记录为：

(isPrivate == 1 AND recepientList CONTAINS "552284302")

前一个谓词查找数值，而后一个谓词查找字符串。请注意，isPrivate==1中的数字未被引用

如果user.userID是一个NSNumber，那么获取它的字符串值应该可以解决这个问题。尝试：

NSString *predicteString = [NSString stringWithFormat:@"isPrivate == %@  AND recepientList contains %@", [NSNumber numberWithBool:YES], [user.userId stringValue]];

---

多亏了@TechZen，他的回答给了我一个提示，让我找到了正确的答案

@TechZen您认为谓词应该作为

(isPrivate == 1 AND recepientList CONTAINS "552284302")

但问题是user.userId不是一个NSNumber，而是一个NSString，所以这行有问题

NSString *predicteString = [NSString stringWithFormat:@"isPrivate == %@  AND recepientList contains %@", [NSNumber numberWithBool:YES], user.userId];

我把这个改成了

 NSString *predicteString = [NSString stringWithFormat:@"isPrivate == %@ ", [NSNumber numberWithBool:YES]];

 predicteString = [predicteString stringByAppendingString:@"AND recepientList contains %@"];
 predicate = [NSPredicate
                 predicateWithFormat:predicteString, user.fbUserId];

---

就这样，我得到了预期的结果。我不知道为什么NSString stringWithFormat将NSString视为NSNumber，而NSPredicate则以正确的方式处理它。

多亏了@TechZen，他的回答给了我一个提示，让我找到了正确的答案

@TechZen您认为谓词应该作为

(isPrivate == 1 AND recepientList CONTAINS "552284302")

但问题是user.userId不是一个NSNumber，而是一个NSString，所以这行有问题

NSString *predicteString = [NSString stringWithFormat:@"isPrivate == %@  AND recepientList contains %@", [NSNumber numberWithBool:YES], user.userId];

我把这个改成了

 NSString *predicteString = [NSString stringWithFormat:@"isPrivate == %@ ", [NSNumber numberWithBool:YES]];

 predicteString = [predicteString stringByAppendingString:@"AND recepientList contains %@"];
 predicate = [NSPredicate
                 predicateWithFormat:predicteString, user.fbUserId];

---

就这样，我得到了预期的结果。我不知道为什么NSString stringWithFormat将NSString视为NSNumber，而NSPredicate将其视为正确的方式。

感谢TechZen的快速响应，user.userId是NSString，但它不是NSNumber，我不会每次都收到此错误，有时我会看到此错误，有时我不会，我可以告诉你，被记录的谓词把它当作一个数字。字符串应该是双引号或单引号。您可以使用带有recpientList键的字典数组来测试谓词。您将得到与上面相同的错误。这显然是谓词解析的问题。感谢TechZen的快速响应，user.userId只是NSString，而不是NSNumber，我不会每次都收到这个错误，有时我看到这个错误，有时我没有。好吧，我可以告诉你，日志中的谓词将它视为一个数字。字符串应该是双引号或单引号。您可以使用带有recpientList键的字典数组来测试谓词。您将得到与上面相同的错误。这显然是谓词解析的问题。