这是返回错误的原因:
NSMutableArray *newArray = [[[NSMutableArray alloc] initWithArray:[NSJSONSerialization JSONObjectWithData:[[[appDelegate.Matches objectAtIndex:(NSUInteger)indexPath] objectForKey:@"chat"] dataUsingEncoding:NSUTF8StringEncoding] options:NSJSONReadingMutableContainers error:nil]] addObject:[NSDictionary dictionaryWithObjectsAndKeys:message, @"message", [NSString stringWithFormat:@"%llu", appDelegate.userId], @"id", nil]];