switch-statement - 发送电子邮件 - MFMailComposeResult

Question

我正在尝试将我的一个应用程序从 Obj-C 迁移到 Swift，但我遇到了电子邮件管理方面的问题。
我按小时搜索，但没有找到解决此问题的方法。
基本上，我正在尝试迁移 func mailComposeController(controller: MFMailComposeViewController!, didFinishWithResult result: MFMailComposeResult, error: NSError!) 函数。

问题是开关内的所有选项均无效。

func mailComposeController(controller: MFMailComposeViewController!, didFinishWithResult result: MFMailComposeResult, error: NSError!)
{
    switch result.value
    {
        case CUnsignedInt(MFMailComposeResultCancelled):
            var alert = UIAlertController(
                title: NSLocalizedString("sendingStatus", tableName: "LocalizationFile", comment:"sendingStatus"),
                message: NSLocalizedString("emailCancelledByUser", tableName: "LocalizationFile", comment:"emailCancelledByUser"),
                preferredStyle: UIAlertControllerStyle.Alert)
            self.presentViewController(alert, animated: true, completion: nil)
        case MFMailComposeResult(MFMailComposeResultFailed):
            var alert = UIAlertController(
                title: NSLocalizedString("sendingStatus", tableName: "LocalizationFile", comment:"sendingStatus"),
                message: NSLocalizedString("emailSentFailed", tableName: "LocalizationFile", comment:"emailSentFailed"),
                preferredStyle: UIAlertControllerStyle.Alert)
            self.presentViewController(alert, animated: true, completion: nil)
        case MFMailComposeResultSaved:
            var alert = UIAlertController(
                title: NSLocalizedString("sendingStatus", tableName: "LocalizationFile", comment:"sendingStatus"),
                message: NSLocalizedString("emailSaved", tableName: "LocalizationFile", comment:"emailSaved"),
                preferredStyle: UIAlertControllerStyle.Alert)
            self.presentViewController(alert, animated: true, completion: nil)
        default:
            var alert = UIAlertController(
                title: NSLocalizedString("sendingStatus", tableName: "LocalizationFile", comment:"sendingStatus"),
                message: NSLocalizedString("emailNotSent", tableName: "LocalizationFile", comment:"emailNotSent"),
                preferredStyle: UIAlertControllerStyle.Alert)
            self.presentViewController(alert, animated: true, completion: nil)
    }
}

Answer 1

不要忘记，您还可以对要与变量结果进行比较的特定结果类型使用 .rawValue(在旧版本的 Swift 中为 .value) :

    var result:MFMailComposeResult = MFMailComposeResultCancelled

    switch(result.value) { // <-- Here, note .value is being used
        case MFMailComposeResultCancelled.value: // <-- And here as well!
            print("Cancelled")
        default:
            print("Default")
    }