【发布时间】：2014-09-24 02:17:29
【问题描述】：
试图找出Core Data Errors Error，并查看MOC的save方法返回的NSError中的userInfo。
iphone-core-data-unresolved-error-while-saving 由于我的分数不足，我无法做出表扬或提出问题。
谁能帮我指出以下键在 Apple Doc、NSValidationErrorObject、NSValidationErrorKey...等中定义的位置？
我的理解是：如果 CoreData 的错误码 == NSValidationMultipleErrorsError，那么 NSError 的 userInfo(dictionary) 将包含所有详细的单一错误信息，并且所有这些详细的单一错误都可以从存储在“NSDetailedErrorsKey”下的数组中访问来自用户信息。
我只是在核心数据常量参考中没有看到它们（NSValidationErrorObject、NSValidationErrorKe...）...？？？它们不透明吗？
谢谢。
- (BOOL)saveData {
NSError *error;
if (![_sharedManagedObjectContext save:&error]) {
// If Cocoa generated the error...
NSString *message = nil;
if ([[error domain] isEqualToString:@"NSCocoaErrorDomain"]) {
// ...check whether there's an NSDetailedErrors array
NSDictionary *userInfo = [error userInfo];
if ([userInfo valueForKey:@"NSDetailedErrors"] != nil) {
// ...and loop through the array, if so.
NSArray *errors = [userInfo valueForKey:@"NSDetailedErrors"];
for (NSError *anError in errors) {
NSDictionary *subUserInfo = [anError userInfo];
subUserInfo = [anError userInfo];
// Granted, this indents the NSValidation keys rather a lot
// ...but it's a small loss to keep the code more readable.
NSLog(@"Core Data Save Error\n\n \
NSValidationErrorKey\n%@\n\n \
NSValidationErrorPredicate\n%@\n\n \
NSValidationErrorObject\n%@\n\n \
NSLocalizedDescription\n%@",
[subUserInfo valueForKey:@"NSValidationErrorKey"],
[subUserInfo valueForKey:@"NSValidationErrorPredicate"],
[subUserInfo valueForKey:@"NSValidationErrorObject"],
[subUserInfo valueForKey:@"NSLocalizedDescription"]);
}
}
// If there was no NSDetailedErrors array, print values directly
// from the top-level userInfo object. (Hint: all of these keys
// will have null values when you've got multiple errors sitting
// behind the NSDetailedErrors key.
else {
NSLog(@"Core Data Save Error\n\n \
NSValidationErrorKey\n%@\n\n \
NSValidationErrorPredicate\n%@\n\n \
NSValidationErrorObject\n%@\n\n \
NSLocalizedDescription\n%@",
[userInfo valueForKey:@"NSValidationErrorKey"],
[userInfo valueForKey:@"NSValidationErrorPredicate"],
[userInfo valueForKey:@"NSValidationErrorObject"],
[userInfo valueForKey:@"NSLocalizedDescription"]);
}
}
// Handle mine--or 3rd party-generated--errors
else {
NSLog(@"Custom Error: %@", [error localizedDescription]);
}
return NO;
}
return YES;
}
[1]: https://stackoverflow.com/questions/1283960/iphone-core-data-unresolved-error-while-saving
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标签： ios core-data runtime-error