未收到从 MFMailComposer 发送的附件

我正在尝试在 iPad 上发送一封带有 .csv 附件的电子邮件。我根据下面显示的许多示例使用 MFMailComposer。发送电子邮件时，我可以在 MFMailComposer 窗口中看到正确的文件附件，但是当我收到电子邮件时，没有附加任何内容。任何关于我可能做错了什么的指导将不胜感激。感谢您的时间，

if ([MFMailComposeViewController canSendMail]) {

    MFMailComposeViewController *mailViewController = [[MFMailComposeViewController alloc] init];
    mailViewController.mailComposeDelegate = self;
    [mailViewController setSubject:[NSString stringWithFormat:@"Results for Participant %d.", [delegate participantNumber]]];
    [mailViewController setMessageBody:[NSString stringWithFormat:@"The results for Participant %d in Study: %@ are as follows:", [delegate participantNumber], [[delegate getAccountData:([delegate accountItems] * [delegate accountNumberInUse])] description]] isHTML:NO];

    NSData *textData = [[NSData alloc] initWithContentsOfFile:dataFileName];
    [mailViewController addAttachmentData:textData mimeType:@"text/csv" fileName:[NSString stringWithFormat:@"Participant_Info_#%d.csv", [delegate participantNumber]]];

    [self presentModalViewController:mailViewController animated:YES];
    [mailViewController release];

} 

检查 textData 变量的内容（只是从代码中猜测） dataFileName 需要包含文件的完整系统路径，而不仅仅是它的名称！

NSString *dataFilePath = [[NSBundle mainBundle] pathForResource:dataFileName ofType:nil];