Question

我正在制作聊天应用，我想保存到核心数据用户个人资料（图片，姓名，年龄，详细信息），这与其他用户进行了对话。在需要保存所有新消息时，我需要我可以看到消息被读取，如果用户想要查看他的历史记录，我将从Web服务器加载它（如滚动到VC顶部）。

我使用该代码来保存和加载消息，但是如何将我的结果数组用于2个确切用户的构建聊天历史记录？

//this code in XMPPStream
 xmppStream = [[XMPPStream alloc]init];
[xmppStream addDelegate:self delegateQueue:dispatch_get_main_queue()];
 xmppStream.autoStartTLS = YES;

 xmppReconnect = [[XMPPReconnect alloc]init];
[xmppReconnect activate:self.xmppStream];

 xmppMessageArchivingCoreDataStorage = [XMPPMessageArchivingCoreDataStorage sharedInstance];
 xmppMessageArchivingModule = [[XMPPMessageArchiving alloc]initWithMessageArchivingStorage:xmppMessageArchivingCoreDataStorage];
[xmppMessageArchivingModule setClientSideMessageArchivingOnly:YES];
[xmppMessageArchivingModule activate:xmppStream];    //By this line all your messages are stored in CoreData
[xmppMessageArchivingModule addDelegate:self delegateQueue:dispatch_get_main_queue()];

在谈话VC中检索已保存的消息

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];

 NSManagedObjectContext *context = [self.xmppMessageArchivingCoreDataStorage mainThreadManagedObjectContext];
 NSEntityDescription *messageEntity = [NSEntityDescription entityForName:@"XMPPMessageArchiving_Message_CoreDataObject" inManagedObjectContext:context];

 fetchRequest.entity = messageEntity;

 NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"timestamp" ascending:NO];
 fetchRequest.sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
 NSError *error = nil;
 NSArray *results = [context executeFetchRequest:fetchRequest error:&error];
//Now I get the NSArray with element type of "XMPPMessageArchiving_Message_CoreDataObject"

Answer 1

如果有人仍然需要答案：

只需将此谓词添加到您的请求中即可。

fetchRequest.predicate = [NSPredicate predicateWithFormat:@"bareJidStr = %@", user.jid];

在核心数据中保存并加载xmpp消息

1 个答案: