我正在尝试将一些Core Data代码从测试Mac OS应用程序移植到iPhone应用程序。我设置了一个帮助方法来管理所有提取代码，并且在Mac OS上一切都很好用，但是我在iPhone上遇到了这个错误：
Detected an attempt to call a symbol in system libraries that is not present on the iPhone:
_Unwind_Resume called from function -[NSSQLAdapter _newSelectStatementWithFetchRequest:ignoreInheritance:] in image CoreData.
以下是调用辅助方法的代码：
// get authors and title THIS WORKS
NSArray *bookInfoFetchResults = [self getEntitiesByName:kOC_CD_ObjectKey_bookInfo
usingPredicateValue:@"contentRoot.bookInfo.bookAuthors > \"\""
withSubstitutionVariables:[NSDictionary dictionaryWithObjectsAndKeys:nil]
inModel:model
andContext:context
sortByAttribute:nil];
int thisResult = 0;
int lastResult = [bookInfoFetchResults count];
for (thisResult = 0; thisResult < lastResult; thisResult++) {
NSManagedObject *currentResult = [bookInfoFetchResults objectAtIndex:thisResult];
NSLog(@"bookAuthors: %@", [currentResult valueForKey:kOC_CD_ObjectAttribute_bookAuthors]);
NSLog(@"bookTitle: %@", [currentResult valueForKey:kOC_CD_ObjectAttribute_bookTitle]);
}
// get chapters THIS DOES NOT WORK
NSArray *chapterFetchResults = [self getEntitiesByName:kOC_CD_ObjectKey_chapter
usingPredicateValue:@"ALL contentRoot.chapters.title > \"\""
withSubstitutionVariables:[NSDictionary dictionaryWithObjectsAndKeys:nil]
inModel:model
andContext:context
sortByAttribute:kOC_CD_ObjectAttribute_key];
int thisChapterResult = 0;
int lastChapterResult = [chapterFetchResults count];
for (thisChapterResult = 0; thisChapterResult < lastChapterResult; thisChapterResult++) {
NSManagedObject *currentChapterResult = [chapterFetchResults objectAtIndex:thisChapterResult];
NSLog(@"Chapter %@: %@", [currentChapterResult valueForKey:kOC_CD_ObjectAttribute_number], [currentChapterResult valueForKey:kOC_CD_ObjectAttribute_title]);
}
辅助方法（删除了错误检查，但删除了没有改变结果错误）：
- (NSArray *) getEntitiesByName:(NSString *)entityName usingPredicateValue:(NSString *)predicateValue withSubstitutionVariables:(NSDictionary *)variablesDict inModel:(NSManagedObjectModel *)aModel andContext:(NSManagedObjectContext *)aContext sortByAttribute:(NSString *)sortingAttribute; {
NSArray *fetchResults;
NSString *fetchRequestTemplateName = [NSString stringWithFormat:@"get_%@", entityName];
NSFetchRequest *fetchRequestTemplate = [[NSFetchRequest alloc] init];
NSEntityDescription *targetEntityDescription;
targetEntityDescription = [[aModel entitiesByName] objectForKey:entityName];
[fetchRequestTemplate setEntity:targetEntityDescription];
// need to find a way to catch an error here in case we give something that isn't right
// NSInvalidArgumentException: Unable to parse the format string "MQaynH5bXs"
NSPredicate *predicateTemplate = [NSPredicate predicateWithFormat:predicateValue];
[fetchRequestTemplate setPredicate:predicateTemplate];
[aModel setFetchRequestTemplate:fetchRequestTemplate forName:fetchRequestTemplateName];
[fetchRequestTemplate release];
if (variablesDict == nil) {
variablesDict = [NSDictionary dictionaryWithObjectsAndKeys:nil];
[variablesDict retain];
}
NSFetchRequest *fetchRequestToExecute = [aModel fetchRequestFromTemplateWithName:fetchRequestTemplateName substitutionVariables:variablesDict];
NSError *fetchError;
fetchResults = [aContext executeFetchRequest:fetchRequestToExecute error:&fetchError];
if ((sortingAttribute != nil) && (fetchResults != nil)) {
NSSortDescriptor *attributeSorter = [[NSSortDescriptor alloc] initWithKey:sortingAttribute ascending:YES];
fetchResults = [fetchResults sortedArrayUsingDescriptors:[NSArray arrayWithObject:attributeSorter]];
[attributeSorter release];
}
return fetchResults;
}
辅助方法的失败点是：
fetchResults = [aContext executeFetchRequest:fetchRequestToExecute error:&fetchError];
从帮助方法中分解代码也不起作用。
我不知道它是否会有所帮助，但在我的帮助方法中删除了我的错误处理代码后，我得到了这个：
2010-11-30 16:31:30.633 OC Flash Card Core 2[19306:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unsupported predicate (null)'
*** Call stack at first throw:
(
0 CoreFoundation 0x02655b99 __exceptionPreprocess + 185
1 libobjc.A.dylib 0x027a540e objc_exception_throw + 47
2 CoreData 0x02381e86 -[NSSQLGenerator generateSQLStatementForFetchRequest:ignoreInheritance:countOnly:] + 1254
3 CoreData 0x023816f0 -[NSSQLAdapter _newSelectStatementWithFetchRequest:ignoreInheritance:] + 480
4 CoreData 0x02381501 -[NSSQLAdapter newSelectStatementWithFetchRequest:] + 49
5 CoreData 0x023813ae -[NSSQLCore newRowsForFetchPlan:] + 430
6 CoreData 0x02380b09 -[NSSQLCore objectsForFetchRequest:inContext:] + 297
7 CoreData 0x023806fe -[NSSQLCore executeRequest:withContext:error:] + 206
8 CoreData 0x0242e91c -[NSPersistentStoreCoordinator executeRequest:withContext:error:] + 1084
9 CoreData 0x0237d897 -[NSManagedObjectContext executeFetchRequest:error:] + 359
10 OC Flash Card Core 2 0x0000360e -[OCContentImporterObj getEntitiesByName:usingPredicateValue:withSubstitutionVariables:inModel:andContext:sortByAttribute:] + 481
11 OC Flash Card Core 2 0x00002af7 -[OCContentImporterObj testCoreDataIntegrity] + 188
12 OC Flash Card Core 2 0x00002864 -[OCContentImporterObj importContent] + 88
13 OC Flash Card Core 2 0x0000252b -[AppDelegate_iPhone application:didFinishLaunchingWithOptions:] + 91
14 UIKit 0x002b4f27 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1163
15 UIKit 0x002b73b0 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 346
16 UIKit 0x002c13ec -[UIApplication handleEvent:withNewEvent:] + 1958
17 UIKit 0x002b9b3c -[UIApplication sendEvent:] + 71
18 UIKit 0x002be9bf _UIApplicationHandleEvent + 7672
19 GraphicsServices 0x02f35822 PurpleEventCallback + 1550
20 CoreFoundation 0x02636ff4 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
21 CoreFoundation 0x02597807 __CFRunLoopDoSource1 + 215
22 CoreFoundation 0x02594a93 __CFRunLoopRun + 979
23 CoreFoundation 0x02594350 CFRunLoopRunSpecific + 208
24 CoreFoundation 0x02594271 CFRunLoopRunInMode + 97
25 UIKit 0x002b6c6d -[UIApplication _run] + 625
26 UIKit 0x002c2af2 UIApplicationMain + 1160
27 OC Flash Card Core 2 0x00001ce0 main + 102
28 OC Flash Card Core 2 0x00001c71 start + 53
)
terminate called after throwing an instance of 'NSException'
但是，再一次，所有这些都在Mac OS中完美运行。我已经尝试过搜索_Unwind_Resume，但它似乎是苹果公司的一个错误，并且至少有十几种不同的方法可以解决它以及十几种不同的解决方法。我能想到的唯一区别是，一次尝试只在CD存储中有一个实例（故意这样），第二个，麻烦一个，可以有很多。有什么想法吗？
答案 0 :(得分：0)
弄清楚如何解决这个问题：在用于搜索的谓词中，ALL关键字必须为ANY。
我不明白为什么就是这种情况。给出的错误似乎相当模糊，而且它以EXC_BAD_ACCESS结束的事实非常令人不安。我愿意接受任何可以解释为什么ANY和ALL之间存在差异的人的答案。