后台抓取导致应用程序冻结而不是前台抓取
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【中文标题】后台抓取导致应用程序冻结而不是前台抓取【英文标题】：background fetching causes app freeze than foreground fetching 【发布时间】：2015-04-28 10:54:27 【问题描述】：我已经在 coredata 中实现了后台提取，但它仍然比正常提取冻结了几秒钟的应用程序。有什么我可以做的快速获取吗？似乎它仍在前台获取，不知道代码有什么问题。
- (void)sr_executeFetchRequest:(NSFetchRequest *)request completion:(void (^)(NSArray *objects, NSError *error))completion
NSString *loginUser=[[NSUserDefaults standardUserDefaults] valueForKey:@"currentUser"];
AppDelegate *sharedDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
NSPersistentStoreCoordinator *coordinator = [sharedDelegate persistentStoreCoordinator];
NSManagedObjectContext *context = [sharedDelegate managedObjectContext];
NSManagedObjectContext *backgroundContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
backgroundContext.persistentStoreCoordinator = coordinator;
[backgroundContext performBlock:^
// Fetch into shared persistent store in background thread
NSError *error = nil;
// NSLog(@"BG thread===== ");
NSArray *fetchedObjects = [backgroundContext executeFetchRequest:request error:&error];
[context performBlock:^
if (fetchedObjects)
// Collect object IDs
NSMutableArray *mutObjectIds = [[NSMutableArray alloc] initWithCapacity:[fetchedObjects count]];
for (NSManagedObject *obj in fetchedObjects)
[mutObjectIds addObject:obj.objectID];
// NSLog(@"BG bg===== ");
// Fault in objects into current context by object ID as they are available in the shared persistent store
NSMutableArray *mutObjects = [[NSMutableArray alloc] initWithCapacity:[mutObjectIds count]];
for (NSManagedObjectID *objectID in mutObjectIds)
NSManagedObject *obj = [context objectWithID:objectID];
[mutObjects addObject:obj];
// NSLog(@"BG fg===== ");
if (completion)
NSArray *objects = [mutObjects copy];
completion(objects, nil);
else
if (completion)
completion(nil, error);
];
];
我在服务器中有一些记录，当后台到前台时，应用程序服务器将发送所有记录，并且从客户端我将所有数据保存到 coredata 中。保存时我需要检查这些数据是否已经存在，有时我需要在保存之前从数据库中获取一些数据，但是在这些时候我的应用程序被冻结了，只有在所有更新和保存完成后才能正常工作。
Profiler 跟踪 https://www.dropbox.com/s/6b1gykvs1pezrcp/Instruments4.trace.zip?dl=0
保存到数据库
-(void)updateThreadEntityWithSyncDetails:(NSMutableDictionary *)inDictionary
NSString *loginUser=[[NSUserDefaults standardUserDefaults] valueForKey:@"currentUser"];
AppDelegate *sharedDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
NSManagedObjectContext *context = [sharedDelegate managedObjectContext];
// NSManagedObjectContext *writerContext = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
// [writerContext setPersistentStoreCoordinator:[sharedDelegate persistentStoreCoordinator]];
////
//// // create main thread MOC
// context = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSMainQueueConcurrencyType];
// context.parentContext = writerContext;
////
NSManagedObjectContext *contextforThread = [[NSManagedObjectContext alloc] initWithConcurrencyType:NSPrivateQueueConcurrencyType];
contextforThread.parentContext = context;
[contextforThread performBlock:^
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
[fetchRequest setReturnsObjectsAsFaults:NO];
NSEntityDescription *entity = [NSEntityDescription entityForName:@"ThreadInfo"
inManagedObjectContext:context];
[fetchRequest setEntity:entity];
NSPredicate *userPredicate = [NSPredicate predicateWithFormat:@"userEmail == %@",loginUser];
NSPredicate *threadPredicate = [NSPredicate predicateWithFormat:@"threadID == %@",[inDictionary valueForKey:@"thread"]];
NSPredicate *compoundPredicate = [NSCompoundPredicate andPredicateWithSubpredicates: @[userPredicate, threadPredicate]];
[fetchRequest setPredicate:compoundPredicate];
NSArray *fetchedObjects = [context executeFetchRequest:fetchRequest error:nil];
for (ThreadInfo *threadInfo in fetchedObjects)
if([[inDictionary allKeys] containsObject:@"userEmail"])
if([inDictionary valueForKey:@"userEmail"]!=[NSNull null])
threadInfo.userEmail=[inDictionary valueForKey:@"userEmail"];
if([[inDictionary allKeys] containsObject:@"badgeValue"])
if([inDictionary valueForKey:@"badgeValue"]!=[NSNull null])
threadInfo.badgeValue=[inDictionary valueForKey:@"badgeValue"];
if([[inDictionary allKeys] containsObject:@"thread"])
if([inDictionary valueForKey:@"thread"]!=[NSNull null])
threadInfo.threadID=[inDictionary valueForKey:@"thread"];
if([[inDictionary allKeys] containsObject:@"key"])
if([inDictionary valueForKey:@"key"]!=[NSNull null])
threadInfo.threadKey=[inDictionary valueForKey:@"key"];
if([[inDictionary allKeys] containsObject:@"secret_seed"])
if([inDictionary valueForKey:@"secret_seed"]!=[NSNull null])
threadInfo.threadSecret=[NSString stringWithFormat:@"%@",[inDictionary valueForKey:@"secret_seed"]];
if([[inDictionary allKeys] containsObject:@"r_key"])
if([inDictionary valueForKey:@"r_key"]!=[NSNull null])
threadInfo.remoteKey=[inDictionary valueForKey:@"r_key"];
if([[inDictionary allKeys] containsObject:@"solicitation"])
if([inDictionary valueForKey:@"solicitation"]!=[NSNull null])
threadInfo.solicitationID=[inDictionary valueForKey:@"solicitation"];
if([[inDictionary allKeys] containsObject:@"r_secret"])
if([inDictionary valueForKey:@"r_secret"]!=[NSNull null])
threadInfo.remoteSecret=[inDictionary valueForKey:@"r_secret"];
if([[inDictionary allKeys] containsObject:@"icon_idx"])
if([inDictionary valueForKey:@"icon_idx"]!=[NSNull null])
threadInfo.avatarIconIndex=[inDictionary valueForKey:@"icon_idx"];
if([[inDictionary allKeys] containsObject:@"icon_color_idx"])
if([inDictionary valueForKey:@"icon_color_idx"]!=[NSNull null])
threadInfo.avatarColorIndex=[inDictionary valueForKey:@"icon_color_idx"];
if([[inDictionary allKeys] containsObject:@"encrypted_r_secret"])
if([inDictionary valueForKey:@"encrypted_r_secret"]!=[NSNull null])
threadInfo.encryptedRemoteSecret=[inDictionary valueForKey:@"encrypted_r_secret"];
if([[inDictionary allKeys] containsObject:@"isSystemMessage"])
if([inDictionary valueForKey:@"isSystemMessage"]!=[NSNull null])
threadInfo.isSystemMessage=[inDictionary valueForKey:@"isSystemMessage"];
if([[inDictionary allKeys] containsObject:@"ref"])
if([inDictionary valueForKey:@"ref"]!=[NSNull null])
threadInfo.systemReferenceURL=[inDictionary valueForKey:@"ref"];
if([[inDictionary allKeys] containsObject:@"url"])
if([inDictionary valueForKey:@"url"]!=[NSNull null])
threadInfo.systemMessageURL=[inDictionary valueForKey:@"url"];
if([[inDictionary allKeys] containsObject:@"thumbnailImageURL"])
if([inDictionary valueForKey:@"thumbnailImageURL"]!=[NSNull null])
threadInfo.thumbnailImageURL=[inDictionary valueForKey:@"thumbnailImageURL"];
if([[inDictionary allKeys] containsObject:@"from"])
if([inDictionary valueForKey:@"from"]!=[NSNull null])
threadInfo.receiverEmail=[inDictionary valueForKey:@"from"];
if([[inDictionary allKeys] containsObject:@"isQuiz"])
if([inDictionary valueForKey:@"isQuiz"]!=[NSNull null])
threadInfo.isQuiz=[inDictionary valueForKey:@"isQuiz"];
if([[inDictionary allKeys] containsObject:@"replied"])
if([inDictionary valueForKey:@"replied"]!=[NSNull null])
threadInfo.replied=[inDictionary valueForKey:@"replied"];
if([[inDictionary allKeys] containsObject:@"owned"])
if([inDictionary valueForKey:@"owned"]!=[NSNull null])
BOOL isOwner=[[inDictionary valueForKey:@"owned"] boolValue];
if([[inDictionary allKeys] containsObject:@"solicitation"])
if([inDictionary valueForKey:@"solicitation"]!=[NSNull null])
if(isOwner)
if ([[inDictionary valueForKey:@"solicitation"] isEqualToString:[inDictionary valueForKey:@"thread"]])
threadInfo.isRequester=[NSNumber numberWithBool:YES];
else
threadInfo.isSender=[NSNumber numberWithBool:YES];
else
// threadInfo.isProvider=[NSNumber numberWithBool:YES];
if ([[inDictionary valueForKey:@"solicitation"] isEqualToString:[inDictionary valueForKey:@"thread"]])
threadInfo.isProvider=[NSNumber numberWithBool:YES];
else
threadInfo.isReceiver=[NSNumber numberWithBool:YES];
else
if(isOwner)
threadInfo.isSender=[NSNumber numberWithBool:YES];
else
threadInfo.isReceiver=[NSNumber numberWithBool:YES];
else
if(isOwner)
threadInfo.isSender=[NSNumber numberWithBool:YES];
else
threadInfo.isReceiver=[NSNumber numberWithBool:YES];
if([[inDictionary allKeys] containsObject:@"options"])
if([inDictionary valueForKey:@"options"]!=[NSNull null])
NSMutableArray *accArray=[inDictionary valueForKey:@"options"];
NSData *arrayData = [NSKeyedArchiver archivedDataWithRootObject:accArray];
threadInfo.pollOptions = arrayData;
if([[inDictionary allKeys] containsObject:@"isAnyReceiverActivity"])
if([inDictionary valueForKey:@"isAnyReceiverActivity"]!=[NSNull null])
threadInfo.isAnyReceiverActivity=[inDictionary valueForKey:@"isAnyReceiverActivity"];
if([[inDictionary allKeys] containsObject:@"pollAnswerList"])
if([inDictionary valueForKey:@"pollAnswerList"]!=[NSNull null])
NSMutableDictionary *accDict=[inDictionary valueForKey:@"pollAnswerList"];
NSData *dictData = [NSKeyedArchiver archivedDataWithRootObject:accDict];
threadInfo.pollAnswerList = dictData;
if([[inDictionary allKeys] containsObject:@"responseCount"])
if([inDictionary valueForKey:@"responseCount"]!=[NSNull null])
threadInfo.responseCount=[inDictionary valueForKey:@"responseCount"];
if([[inDictionary allKeys] containsObject:@"isSender"])
if([inDictionary valueForKey:@"isSender"]!=[NSNull null])
threadInfo.isSender=[NSNumber numberWithBool:[[inDictionary valueForKey:@"isSender"] boolValue]];
if([[inDictionary allKeys] containsObject:@"isRequester"])
if([inDictionary valueForKey:@"isRequester"]!=[NSNull null])
threadInfo.isRequester=[NSNumber numberWithBool:[[inDictionary valueForKey:@"isRequester"] boolValue]];
if([[inDictionary allKeys] containsObject:@"image"])
if([inDictionary valueForKey:@"image"]!=[NSNull null])
threadInfo.image=[inDictionary valueForKey:@"image"];
if([[inDictionary allKeys] containsObject:@"isReceiver"])
if([inDictionary valueForKey:@"isReceiver"]!=[NSNull null])
threadInfo.isReceiver=[NSNumber numberWithBool:[[inDictionary valueForKey:@"isReceiver"] boolValue]];
if([[inDictionary allKeys] containsObject:@"colorCode"])
if([inDictionary valueForKey:@"colorCode"]!=[NSNull null])
threadInfo.colorCode=[inDictionary valueForKey:@"colorCode"];
if([[inDictionary allKeys] containsObject:@"solicitationCount"])
if([inDictionary valueForKey:@"solicitationCount"]!=[NSNull null])
threadInfo.solicitationCount=[inDictionary valueForKey:@"solicitationCount"];
if([[inDictionary allKeys] containsObject:@"solicitationNumber"])
if([inDictionary valueForKey:@"solicitationNumber"]!=[NSNull null])
threadInfo.solicitationNumber=[inDictionary valueForKey:@"solicitationNumber"];
if([[inDictionary allKeys] containsObject:@"disliked"])
if([inDictionary valueForKey:@"disliked"]!=[NSNull null])
threadInfo.hasDislikes=[NSNumber numberWithBool:[[inDictionary valueForKey:@"disliked"] boolValue]];
if([[inDictionary allKeys] containsObject:@"liked"])
if([inDictionary valueForKey:@"liked"]!=[NSNull null])
threadInfo.hasLikes=[NSNumber numberWithBool:[[inDictionary valueForKey:@"liked"] boolValue]];
if([[inDictionary allKeys] containsObject:@"removed"])
if([inDictionary valueForKey:@"removed"]!=[NSNull null])
threadInfo.isThreadRemoved=[NSNumber numberWithBool:[[inDictionary valueForKey:@"removed"] boolValue]];
if([[inDictionary allKeys] containsObject:@"closed"])
if([inDictionary valueForKey:@"closed"]!=[NSNull null])
threadInfo.isThreadEnded=[NSNumber numberWithBool:[[inDictionary valueForKey:@"closed"] boolValue]];
if([[inDictionary allKeys] containsObject:@"blocked"])
if([inDictionary valueForKey:@"blocked"]!=[NSNull null])
threadInfo.isThreadBlocked=[NSNumber numberWithBool:[[inDictionary valueForKey:@"blocked"] boolValue]];
if([[inDictionary allKeys] containsObject:@"hasComments"])
if([inDictionary valueForKey:@"hasComments"]!=[NSNull null])
threadInfo.hasComments=[NSNumber numberWithBool:[[inDictionary valueForKey:@"hasComments"] boolValue]];
if([[inDictionary allKeys] containsObject:@"isProvider"])
if([inDictionary valueForKey:@"isProvider"]!=[NSNull null])
threadInfo.isProvider=[NSNumber numberWithBool:[[inDictionary valueForKey:@"isProvider"] boolValue]];
if([[inDictionary allKeys] containsObject:@"messageDescription"])
if([inDictionary valueForKey:@"messageDescription"]!=[NSNull null])
threadInfo.messageDescription=[inDictionary valueForKey:@"messageDescription"];
if([[inDictionary allKeys] containsObject:@"commentCount"])
if([inDictionary valueForKey:@"commentCount"]!=[NSNull null])
threadInfo.commentCount=[NSNumber numberWithInteger:[[inDictionary valueForKey:@"commentCount"] integerValue]];
if([[inDictionary allKeys] containsObject:@"threadDate"])
if([inDictionary valueForKey:@"threadDate"]!=[NSNull null])
threadInfo.threadDate=[inDictionary valueForKey:@"threadDate"];
if([[inDictionary allKeys] containsObject:@"receivedDate"])
if([inDictionary valueForKey:@"receivedDate"]!=[NSNull null])
threadInfo.receivedDate=[inDictionary valueForKey:@"receivedDate"];
if([[inDictionary allKeys] containsObject:@"closedDate"])
if([inDictionary valueForKey:@"closedDate"]!=[NSNull null])
threadInfo.closedDate=[inDictionary valueForKey:@"closedDate"];
if([[inDictionary allKeys] containsObject:@"blockedDate"])
if([inDictionary valueForKey:@"blockedDate"]!=[NSNull null])
threadInfo.blockedDate=[inDictionary valueForKey:@"blockedDate"];
if([[inDictionary allKeys] containsObject:@"threadDescription"])
if([inDictionary valueForKey:@"threadDescription"]!=[NSNull null])
threadInfo.threadMessage=[inDictionary valueForKey:@"threadDescription"];
if([[inDictionary allKeys] containsObject:@"receiverEmail"])
if([inDictionary valueForKey:@"receiverEmail"]!=[NSNull null])
threadInfo.receiverEmail=[inDictionary valueForKey:@"receiverEmail"];
if([[inDictionary allKeys] containsObject:@"to"])
if([inDictionary valueForKey:@"to"]!=[NSNull null])
id toValue=[inDictionary valueForKey:@"to"];
if([toValue isKindOfClass:[NSString class]])
if ([toValue rangeOfString:@"@"].location != NSNotFound)
threadInfo.receiverEmail=[NSString stringWithFormat:@"%@",toValue];
else
NSMutableArray *accArray=[NSMutableArray arrayWithArray:toValue];
NSData *arrayData = [NSKeyedArchiver archivedDataWithRootObject:accArray];
threadInfo.solicitationList = arrayData;
//Poll
if([[inDictionary allKeys] containsObject:@"isPoll"])
if([inDictionary valueForKey:@"isPoll"]!=[NSNull null])
threadInfo.isPoll=[inDictionary valueForKey:@"isPoll"];
if([[inDictionary allKeys] containsObject:@"type"])
if([inDictionary valueForKey:@"type"]!=[NSNull null])
threadInfo.pollType=[inDictionary valueForKey:@"type"];
if([[inDictionary allKeys] containsObject:@"scope"])
if([inDictionary valueForKey:@"scope"]!=[NSNull null])
threadInfo.pollScope=[inDictionary valueForKey:@"scope"];
if([[inDictionary allKeys] containsObject:@"isPollSender"])
if([inDictionary valueForKey:@"isPollSender"]!=[NSNull null])
threadInfo.isPollSender=[inDictionary valueForKey:@"isPollSender"];
if([[inDictionary allKeys] containsObject:@"visibility"])
if([inDictionary valueForKey:@"visibility"]!=[NSNull null])
threadInfo.pollVisibility=[inDictionary valueForKey:@"visibility"];
if([[inDictionary allKeys] containsObject:@"yesPercentage"])
if([inDictionary valueForKey:@"yesPercentage"]!=[NSNull null])
threadInfo.yesPercentage=[inDictionary valueForKey:@"yesPercentage"];
if([[inDictionary allKeys] containsObject:@"noPercentage"])
if([inDictionary valueForKey:@"noPercentage"]!=[NSNull null])
threadInfo.noPercentage=[inDictionary valueForKey:@"noPercentage"];
if([[inDictionary allKeys] containsObject:@"selectedOption"])
if([inDictionary valueForKey:@"selectedOption"]!=[NSNull null])
threadInfo.selectedOption=[inDictionary valueForKey:@"selectedOption"];
if([[inDictionary allKeys] containsObject:@"selectedStar"])
if([inDictionary valueForKey:@"selectedStar"]!=[NSNull null])
threadInfo.selectedStar=[inDictionary valueForKey:@"selectedStar"];
if([[inDictionary allKeys] containsObject:@"choice1Percentage"])
if([inDictionary valueForKey:@"choice1Percentage"]!=[NSNull null])
threadInfo.choice1Percentage=[inDictionary valueForKey:@"choice1Percentage"];
if([[inDictionary allKeys] containsObject:@"choice2Percentage"])
if([inDictionary valueForKey:@"choice2Percentage"]!=[NSNull null])
threadInfo.choice2Percentage=[inDictionary valueForKey:@"choice2Percentage"];
if([[inDictionary allKeys] containsObject:@"choice3Percentage"])
if([inDictionary valueForKey:@"choice3Percentage"]!=[NSNull null])
threadInfo.choice3Percentage=[inDictionary valueForKey:@"choice3Percentage"];
if([[inDictionary allKeys] containsObject:@"choice4Percentage"])
if([inDictionary valueForKey:@"choice4Percentage"]!=[NSNull null])
threadInfo.choice4Percentage=[inDictionary valueForKey:@"choice4Percentage"];
if([[inDictionary allKeys] containsObject:@"choice5Percentage"])
if([inDictionary valueForKey:@"choice5Percentage"]!=[NSNull null])
threadInfo.choice5Percentage=[inDictionary valueForKey:@"choice5Percentage"];
NSError *error;
if(![contextforThread save:&error])
NSLog(@"Child error : %@",error);
[context performBlock:^
NSError *error;
if(![context save:&error])
NSLog(@"%@",error);
];
];
websocket // 不断从服务器获取数据
- (void)webSocket:(SRWebSocket *)webSocket didReceiveMessage:(id)message
NSDictionary *responseDict = [message JSONValue];
NSArray *bodyDicta=[responseDict objectForKey:@"body"];
for (int i=0; i<bodyDicta.count; i++)
int responseCode=[[[[responseDict objectForKey:@"body"] objectAtIndex:i ] objectForKey:@"code"] intValue];
[self checkResponseCode:[bodyDicta objectAtIndex: i] indexvalue:responseCode isArray:1];
checkResponseCode
-(void)checkResponseCode:(NSDictionary *)responseDict indexvalue:(int)code isArray:(int)flag
if(code==3608)
[self manageGroupDetails:responseDict];
if (code == 3602)// SCROLL ISSUE
[self updateThreadWithSyncDetails:responseDict];
if (code == 3603)
[self updateCommentWithSyncDetails:responseDict];
if(code==3607)// SCROLL ISSUE
[self updateSolicitationWithSyncDetails:responseDict];
updatePollWithSyncDetails
-(void)updatePollWithSyncDetails:(NSDictionary *)responseDict
BOOL isDuplicate=[[IXDataBaseManager sharedNetworkDataManager] checkForExistenceOfThreadDetailsForThreadID:[responseDict objectForKey:@"poll"]];
if(!isDuplicate)
[[IXDataBaseManager sharedNetworkDataManager] updateThreadEntityWithSyncDetails:detailsDict];
updateSolicitationWithSyncDetails
-(void)updateSolicitationWithSyncDetails:(NSDictionary *)inDictionary
NSMutableDictionary *paramDict=[NSMutableDictionary dictionaryWithDictionary:inDictionary];
NSString *userEmail=[[NSUserDefaults standardUserDefaults] valueForKey:@"currentUser"];
[paramDict setObject:[NSNumber numberWithBool:NO] forKey:@"isSystemMessage"];
[paramDict setObject:message forKey:@"threadDescription"];
ThreadInfo *threadInfo=[[IXDataBaseManager sharedNetworkDataManager] retrieveSolicitationInfoForThreadID:[inDictionary objectForKey:@"solicitation"]];
[paramDict setObject:threadInfo.threadID forKey:@"thread"];
[[IXDataBaseManager sharedNetworkDataManager] updateThreadEntityWithSyncDetails:paramDict];
【问题讨论】：
使用 xCode 调试器，您可以在块内添加断点并检查它们在哪个线程中执行。 是的，他们正在执行，我已经 NSlogged 的值。我的代码有什么问题吗？ 【参考方案1】：首先，您怎么知道是 fetch 阻塞了您的 UI？你在这上面运行过 Instruments 吗？如果有，痕迹在哪里？
如果你还没有，那么你需要停止，运行 Instruments，使用 Time Profiler 并找到块。使用跟踪链接更新您的问题，以便下载和查看。
如果没有在 Instruments 中查看此问题，您只是在猜测实际问题是什么。
更新 1
查看您提供的跟踪，我没有看到 Core Data 在主线程（或任何其他线程）上占用任何大量时间。我怀疑你在这里追错了。
您上面的代码不会为您节省任何时间。虽然它会将对象加载到NSPersistentStoreCoordinator 中以使您的主要NSManagedObjectContext 获取它们的速度稍快一些，但这并不重要。根据您的时间跟踪，您没有在 SQL 上花费任何时间（主线程上总共 132 毫秒）。
即使您的 SQL 调用花费了大量时间，它仍然会阻塞主线程，因为您在执行 fetch 时锁定了 NSPersistentStoreCoordinator。
根据您提供的跟踪信息，您的问题出在您的 UI 中。您的大部分时间都花在-[IXInBoxViewController tableView;heightForRowAtIndexPath:] 上，这是锁定 UI 的常见位置。深入了解您的个人资料，找到昂贵的物品并修复它。
问题不在于核心数据。我建议删除此线程代码（添加线程不是性能解决方案）并返回使用 NSFetchedResultsController 和您的 UITableViewController 然后分析您的 UI 代码并修复缓慢的代码。
更新 2
我从服务器获取大量数据并不断节省核心数据。 .我正在使用 NSFetchedResultsController，因此必须重新加载每个储蓄表视图。现在我正在尝试一次保存少量数据，这是处理对核心数据的大量保存请求的正确方法吗？
您没有提供任何用于加载数据或保存数据的代码，因此无论您是否正确执行这些部分，我都无法权威地发言。
您加载的数据量无关紧要，只要它在后台线程的后台上下文中加载（我更喜欢使用 NSOperation 子类）并保存到 Core Data 中。 NSFetchedResultsController 会做正确的事情，除非您同时显示数据，否则对 UI 的影响将是最小的。如果数据正在加载到NSFetchedResultsController 并且相对不在屏幕上，那么它不会对性能产生重大影响。
运行仪器。每当有性能问题时，这是您的第一步。
如果您的数据加载速度很慢，请隔离速度较慢的行并解决它们。
如果您的保存速度很慢（不太可能），请将其分成小块。
但首先对其进行分析。否则你就是在黑暗中拍摄，只是在猜测。
【讨论】：
好的先生，但我通过评论那些需要保存和获取核心数据的方法发现了这个问题。之后它工作正常， 先生，我已经用确切的问题更新了我的问题 谢谢您，先生，我会尝试解决 UI 问题。我不断地从服务器获取大量数据并保存到核心数据。 .我正在使用 NSFetchedResultsController，因此必须重新加载每个储蓄表视图。现在我正在尝试一次保存少量数据，这是处理对核心数据的大量保存请求的正确方法吗？ 请将其移至单独的问题并关闭此问题。 好的，先生，我打开了另一个链接***.com/questions/29959032/…【参考方案2】：你有你的代码行...
backgroundContext.persistentStoreCoordinator = coordinator;
...在区块内。
在开始performBlock 之前尝试为您的 MOC 设置 PSC。
【讨论】：
其实这个抓取是在后台线程中完成的，那为什么主线程阻塞呢？我很混乱。你有什么解决办法吗？ 抱歉之前没有注意到这一点，但是您将主要的context 包裹在 backgroundContent 的 performBlock 方法中。这将阻止您的用户界面
我通过参考得到了这个方法。我的问题是获取阻止我的 UI，这就是我使用后台获取的原因，我不知道是否有另一种方法。你能帮助我吗？在这一点上真的卡住了。以上是关于后台抓取导致应用程序冻结而不是前台抓取的主要内容，如果未能解决你的问题，请参考以下文章