iPhone核心数据“生产”错误处理
iPhone核心数据“生产”错误处理
提问于 2010-02-15 04:49:14
我在Apple提供的示例代码中看到了您应该如何处理核心数据错误的参考。即：
NSError *error = nil;
if (![context save:&error]) {
/*
Replace this implementation with code to handle the error appropriately.
abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button.
*/
NSLog(@"Unresolved error %@, %@", error, [error userInfo]);
abort();
}但是从来没有任何关于你应该如何实现它的例子。
有没有人有(或者可以告诉我)一些实际的“生产”代码来说明上面的方法。
提前谢谢你，马特
回答 3
Stack Overflow用户
回答已采纳
发布于 2010-02-15 05:14:43
没有人会向你展示产品代码，因为它100%依赖于你的应用程序以及错误发生的位置。
就我个人而言，我在其中放了一个assert语句，因为99.9%的时间这个错误会在开发中发生，当你修复它时，你在生产中看到它的可能性很小。
在断言之后，我会向用户显示一个警报，让他们知道发生了一个不可恢复的错误，并且应用程序将要退出。您还可以在其中放置一个格式回复信息，要求他们联系开发人员，这样您就有希望跟踪完成的情况。
在那之后，我会把abort()留在那里，因为它会使应用程序“崩溃”，并生成一个堆栈跟踪，希望以后可以用来追踪这个问题。
Stack Overflow用户
发布于 2010-08-18 18:04:29
这是我提出的一种通用方法，用于在iPhone上处理和显示验证错误。但Marcus是对的:您可能希望调整消息以使其更加用户友好。但这至少给了您一个起点，让您了解哪些字段未验证以及原因。
- (void)displayValidationError:(NSError *)anError {
if (anError && [[anError domain] isEqualToString:@"NSCocoaErrorDomain"]) {
NSArray *errors = nil;
// multiple errors?
if ([anError code] == NSValidationMultipleErrorsError) {
errors = [[anError userInfo] objectForKey:NSDetailedErrorsKey];
} else {
errors = [NSArray arrayWithObject:anError];
}
if (errors && [errors count] > 0) {
NSString *messages = @"Reason(s):\n";
for (NSError * error in errors) {
NSString *entityName = [[[[error userInfo] objectForKey:@"NSValidationErrorObject"] entity] name];
NSString *attributeName = [[error userInfo] objectForKey:@"NSValidationErrorKey"];
NSString *msg;
switch ([error code]) {
case NSManagedObjectValidationError:
msg = @"Generic validation error.";
break;
case NSValidationMissingMandatoryPropertyError:
msg = [NSString stringWithFormat:@"The attribute '%@' mustn't be empty.", attributeName];
break;
case NSValidationRelationshipLacksMinimumCountError:
msg = [NSString stringWithFormat:@"The relationship '%@' doesn't have enough entries.", attributeName];
break;
case NSValidationRelationshipExceedsMaximumCountError:
msg = [NSString stringWithFormat:@"The relationship '%@' has too many entries.", attributeName];
break;
case NSValidationRelationshipDeniedDeleteError:
msg = [NSString stringWithFormat:@"To delete, the relationship '%@' must be empty.", attributeName];
break;
case NSValidationNumberTooLargeError:
msg = [NSString stringWithFormat:@"The number of the attribute '%@' is too large.", attributeName];
break;
case NSValidationNumberTooSmallError:
msg = [NSString stringWithFormat:@"The number of the attribute '%@' is too small.", attributeName];
break;
case NSValidationDateTooLateError:
msg = [NSString stringWithFormat:@"The date of the attribute '%@' is too late.", attributeName];
break;
case NSValidationDateTooSoonError:
msg = [NSString stringWithFormat:@"The date of the attribute '%@' is too soon.", attributeName];
break;
case NSValidationInvalidDateError:
msg = [NSString stringWithFormat:@"The date of the attribute '%@' is invalid.", attributeName];
break;
case NSValidationStringTooLongError:
msg = [NSString stringWithFormat:@"The text of the attribute '%@' is too long.", attributeName];
break;
case NSValidationStringTooShortError:
msg = [NSString stringWithFormat:@"The text of the attribute '%@' is too short.", attributeName];
break;
case NSValidationStringPatternMatchingError:
msg = [NSString stringWithFormat:@"The text of the attribute '%@' doesn't match the required pattern.", attributeName];
break;
default:
msg = [NSString stringWithFormat:@"Unknown error (code %i).", [error code]];
break;
}
messages = [messages stringByAppendingFormat:@"%@%@%@\n", (entityName?:@""),(entityName?@": ":@""),msg];
}
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Validation Error"
message:messages
delegate:nil
cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
[alert show];
[alert release];
}
}
}好好享受吧。
Stack Overflow用户
发布于 2016-08-25 15:35:02
我做了一个很有用的答案的快速版本，它可能会很有用：
public func displayValidationError(anError:NSError?) -> String {
if anError != nil && anError!.domain.compare("NSCocoaErrorDomain") == .OrderedSame {
var messages:String = "Reason(s):\n"
var errors = [AnyObject]()
if (anError!.code == NSValidationMultipleErrorsError) {
errors = anError!.userInfo[NSDetailedErrorsKey] as! [AnyObject]
} else {
errors = [AnyObject]()
errors.append(anError!)
}
if (errors.count > 0) {
for error in errors {
if (error as? NSError)!.userInfo.keys.contains("conflictList") {
messages = messages.stringByAppendingString("Generic merge conflict. see details : \(error)")
}
else
{
let entityName = "\(((error as? NSError)!.userInfo["NSValidationErrorObject"] as! NSManagedObject).entity.name)"
let attributeName = "\((error as? NSError)!.userInfo["NSValidationErrorKey"])"
var msg = ""
switch (error.code) {
case NSManagedObjectValidationError:
msg = "Generic validation error.";
break;
case NSValidationMissingMandatoryPropertyError:
msg = String(format:"The attribute '%@' mustn't be empty.", attributeName)
break;
case NSValidationRelationshipLacksMinimumCountError:
msg = String(format:"The relationship '%@' doesn't have enough entries.", attributeName)
break;
case NSValidationRelationshipExceedsMaximumCountError:
msg = String(format:"The relationship '%@' has too many entries.", attributeName)
break;
case NSValidationRelationshipDeniedDeleteError:
msg = String(format:"To delete, the relationship '%@' must be empty.", attributeName)
break;
case NSValidationNumberTooLargeError:
msg = String(format:"The number of the attribute '%@' is too large.", attributeName)
break;
case NSValidationNumberTooSmallError:
msg = String(format:"The number of the attribute '%@' is too small.", attributeName)
break;
case NSValidationDateTooLateError:
msg = String(format:"The date of the attribute '%@' is too late.", attributeName)
break;
case NSValidationDateTooSoonError:
msg = String(format:"The date of the attribute '%@' is too soon.", attributeName)
break;
case NSValidationInvalidDateError:
msg = String(format:"The date of the attribute '%@' is invalid.", attributeName)
break;
case NSValidationStringTooLongError:
msg = String(format:"The text of the attribute '%@' is too long.", attributeName)
break;
case NSValidationStringTooShortError:
msg = String(format:"The text of the attribute '%@' is too short.", attributeName)
break;
case NSValidationStringPatternMatchingError:
msg = String(format:"The text of the attribute '%@' doesn't match the required pattern.", attributeName)
break;
default:
msg = String(format:"Unknown error (code %i).", error.code) as String
break;
}
messages = messages.stringByAppendingString("\(entityName).\(attributeName):\(msg)\n")
}
}
}
return messages
}
return "no error"
}`页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/2262704
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