JSQMessagesViewController - 在设置日期时收到崩溃以及消息

Question

我正在使用JSQMessagesViewController从服务器发送和接收消息。消息显示正常，但在尝试显示日期时，所有消息都会出现，然后在JSQMessagesTimestampFormatter Library Class上崩溃。这是 - （NSAttributedString *）attributionTimestampForDate：（NSDate *）date

由于未捕获的异常终止应用程序＆＃39; NSInvalidArgumentException＆＃39;，原因：＆＃39; NSConcreteMutableAttributedString initWithString：attributes :: nil value＆＃39;

- (NSAttributedString *)attributedTimestampForDate:(NSDate *)date
{
 if (!date) {
    return nil;
}

NSString *relativeDate = [self relativeDateForDate:date];
NSString *time = [self timeForDate:date];

// TimeStamp

在线下获得崩溃

NSMutableAttributedString *timestamp = [[NSMutableAttributedString alloc] initWithString:relativeDate
                                                                              attributes:self.dateTextAttributes];

[timestamp appendAttributedString:[[NSAttributedString alloc] initWithString:@" "]];

[timestamp appendAttributedString:[[NSAttributedString alloc] initWithString:time
                                                                  attributes:self.timeTextAttributes]];

return [[NSAttributedString alloc] initWithAttributedString:timestamp];
}

我的代码

//获取客户聊天消息

- (void)getCustomerChatMessages
 {
  [[ServiceManager sharedInstance]GetChatMessagesforParentSK:self.str_ChatMessageSK completionBlock:^(id result, NSError *error)
 {
     if (!error)
     {
         NSDictionary *recallsDict = (NSDictionary *)result;
         self.array_CustChatMessage  = [recallsDict valueForKey:@"ChatMessageData"];

         for (NSArray  *dict in self.array_CustChatMessage)
         {


             JSQMessage * copyMessage = [[JSQMessage alloc] initWithSenderId:[[dict valueForKey:@"FromSK"] stringValue]
                                                  senderDisplayName:[dict valueForKey:@"FirstName"]
                                                               date:[dict valueForKey:@"DateCreated"]
                                                               text:[dict valueForKey:@"Message"]];
             [self.messages addObject:copyMessage];

        }

         dispatch_async(dispatch_get_main_queue(), ^{
             [self finishSendingMessageAnimated:YES];
         });
     }
 }];
 }

 - (NSAttributedString *)collectionView:(JSQMessagesCollectionView *)collectionView attributedTextForCellTopLabelAtIndexPath:(NSIndexPath *)indexPath
{
/**
 *  This logic should be consistent with what you return from `heightForCellTopLabelAtIndexPath:`
 *  The other label text delegate methods should follow a similar pattern.
 *
 *  Show a timestamp for every 3rd message
 */
{
    JSQMessage *message = [self.messages objectAtIndex:indexPath.item];

    NSLog(@"\n\n\n Message Date :%@",message.date);

    return [[JSQMessagesTimestampFormatter sharedFormatter] attributedTimestampForDate:message.date];

}

return nil;
}


- (NSAttributedString *)collectionView:(JSQMessagesCollectionView *)collectionView attributedTextForMessageBubbleTopLabelAtIndexPath:(NSIndexPath *)indexPath
{
JSQMessage *message = [self.messages objectAtIndex:indexPath.item];

/**
 *  iOS7-style sender name labels
 */
if ([message.senderId isEqualToString:self.senderId])
{
    return nil;
}

if (indexPath.item - 1 > 0)
{
    JSQMessage *previousMessage = [self.messages objectAtIndex:indexPath.item - 1];
    if ([[previousMessage senderId] isEqualToString:message.senderId]) {
        return nil;
    }
}

/**
 *  Don't specify attributes to use the defaults.
 */


NSLog(@"Sender Display Name:%@",[[NSAttributedString alloc] initWithString:self.strSenderName]);

return [[NSAttributedString alloc] initWithString:self.strSenderName];

}