带有 XLS 附件的 Swift MFMailComposeViewController，未找到附件

Question

我正在使用 XLS 作为附件的 Swift 3.0 (Xcode 8.2.1) 中的 MFMailComposeViewController。我在缓存目录中保存了一个 excel 文件，并为电子邮件的附件检索相同的文件。 （见下面的代码）

当我调试代码时，我看到它打印出“文件数据已加载。”，这意味着有数据来自沙箱（缓存）。不确定，这个 mime 类型是否正确"application/vnd.ms-excel"？

给我的怪！我没有看到邮件正文和附件。你能帮忙吗？

到目前为止，这是我的代码：

import MessageUI
class ViewController:MFMailComposeViewControllerDelegate {
    func shareFileViaEmail() {
        if MFMailComposeViewController.canSendMail() {
                let mailComposerVC = MFMailComposeViewController()
                mailComposerVC.mailComposeDelegate = self


                let paths: [Any] = NSSearchPathForDirectoriesInDomains(.cachesDirectory, .userDomainMask, true)
                let documentsDirectory: String = paths[0] as! String
                let dataPath: URL = URL(fileURLWithPath: documentsDirectory).appendingPathComponent("record.xls").absoluteURL

                if let fileData = NSData(contentsOf: dataPath) {
                    print("File data loaded.")
                    mailComposerVC.addAttachmentData(fileData as Data, mimeType: "application/vnd.ms-excel", fileName: "Report")

                }

                mailComposerVC.setSubject("Report")
                mailComposerVC.setMessageBody("Message body", isHTML: false)
                self.present(mailComposerVC, animated: true, completion: nil)
            }else{

                print("Your device could not send e-mail.  Please check e-mail configuration and try again.")
            }
   }
   func mailComposeController(_ controller:MFMailComposeViewController, didFinishWith result:MFMailComposeResult, error:Error?) {

        self.dismiss(animated: false, completion: nil)
   }

}

我在设备中看到以下输出：（无附件和无电子邮件正文）

Answer 1

下面的代码对我有用。

if( MFMailComposeViewController.canSendMail() ) {


    let mailComposer = MFMailComposeViewController()
    mailComposer.mailComposeDelegate = self

    //Set the subject and message of the email
    mailComposer.setSubject("swift")
    mailComposer.setMessageBody("Testing", isHTML: false)
    let path = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)[0] as String
    let url = NSURL(fileURLWithPath: path)
    let filePath = url.appendingPathComponent("nameOfFileHere")?.path
    let fileManager = FileManager.default
    if fileManager.fileExists(atPath: filePath!) {
        if let fileData = NSData(contentsOfFile: filePath!) {
            print("File data loaded.")
            mailComposer.addAttachmentData(fileData as Data, mimeType: "application/vnd.ms-excel", fileName: "nameOfFileHere")
        }
    } else {
        print("FILE NOT AVAILABLE")
    }

    self.present(mailComposer, animated: true, completion: nil)
}