反向数组内容？

我使用信息填充表视图，但希望将其填充为反向，以便任何新添加的单元格（新电子邮件消息）将显示在顶部而不是底部。反向数组内容？

我在做什么错？

- (UITableViewCell *)tableView:(UITableView *)tableView 
     cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{ 
    static NSString *simpleTableIdentifier = @"MailCell"; 

    MailCell *cell = (MailCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier]; 
    if (cell == nil) 
    { 
     NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"MailCell" owner:self options:nil]; 
     cell = [nib objectAtIndex:0]; 

     // SLICK 
     // Anything that should be the same on EACH cell should be here. 

     UIView *myBackView = [[UIView alloc] initWithFrame:cell.frame]; 
     myBackView.backgroundColor = [UIColor colorWithRed:15.0/255.0 green:140.0/255.0 blue:198.0/255.0 alpha:1]; 
     cell.selectedBackgroundView = myBackView; 

     cell.selectionStyle = UITableViewCellSelectionStyleGray; 
     cell.messageText.textAlignment = NSTextAlignmentLeft; 
     cell.messageText.lineBreakMode = NSLineBreakByTruncatingTail; 
    } 

    NSUInteger row = [indexPath row]; 

    // Extract Data 

    // Use the message object instead of the multiple arrays. 

    CTCoreMessage *message = [[self allMessages] objectAtIndex:row]; 

    // Sender 

    CTCoreAddress *sender = [message sender]; 
    NSString *senderName = [sender name]; 

    // Subject 

    NSString *subject = [message subject]; 
    if ([subject length] == 0) 
    { 
     subject = @"(No Subject)"; 
    } 

    // Body 

    BOOL isPlain = YES; 
    NSString *body = [message bodyPreferringPlainText:&isPlain]; 
    body = [body stringByReplacingOccurrencesOfString:@"\n" withString:@" "]; 
    body = [body stringByReplacingOccurrencesOfString:@"\r" withString:@" "]; 

    // Populate Cell 

    [[cell nameText] setText:senderName]; 
    [[cell subjectField] setText:subject]; 
    [[cell messageText] setText:body]; 

    if ([message isUnread]) 
    { 
     UIColor *myColor = [UIColor colorWithRed:15.0/255.0 green:140.0/255.0 blue:198.0/255.0 alpha:1.0]; 
     cell.nameText.textColor = myColor; 
    } 
    else 
    { 
     cell.nameText.textColor = [UIColor blackColor]; 
    } 

    return cell; 

}

我是如何加载阵列：

- (NSMutableArray *)allMessages 
{ 
    if (_allMessages == nil) 
    { 
     _allMessages = [[NSMutableArray alloc] init]; 
    } 
    return _allMessages; 
}

来源

2013-04-23 Isa Ranjha

您从NSArray的指数[indexPath row]拉意味着你开始在索引0和去到n。这意味着你不是相反的顺序。您需要先倒置阵列。一个简单的方法是：

- (void)viewWillAppear:(BOOL)animated 
{ 
    NSArray *allMessages = [self allMessages]; 
    NSArray* reversedMessages = [[allMessages reverseObjectEnumerator] allObjects]; 
}

然后在您的cellForRowAtIndexPath方法，你可以这样做：

CTCoreMessage *message = [reversedMessages objectAtIndex:row];

来源

2013-04-23 22:02:04 JeffN

谢谢您的回答，您可以请张贴代码到我现有的代码，因为我不完全知道该从阵列中拉出什么。如果你愿意，只要告诉我该放哪里（或替换什么），我会将其标记为答案。谢谢！ – 2013-04-23 22:05:22

您需要在cellForRowAtIndexPath方法之外执行此操作，因此每次单元加载时都不会发生这种情况，可能在您的viewWillAppear中。你会想要用你的allMessages数组来做，检查编辑。 – JeffN 2013-04-23 22:08:21

这是我如何加载allMessages，检查编辑。 – 2013-04-23 22:29:46

反向数组内容？

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