Ios 在swift 3中共享mp3文件

我想在收藏视图单元格中长按时共享MP3文件。我写了下面的代码，但它没有返回任何内容。我是说当我给自己发电子邮件的时候。它不包括MP3文件，而且我也看不到WhatsApp部分

 let r = NSURL(fileURLWithPath: temp_url!)
    //var activityItems: [Any] = [temp_url!]
    let activityViewController = UIActivityViewController(activityItems: [r], applicationActivities: nil)
    activityViewController.popoverPresentationController?.sourceView = self.view // so that iPads won't crash

    // exclude some activity types from the list (optional)
     let excludeActivities = [UIActivityType.airDrop, UIActivityType.print, UIActivityType.assignToContact, UIActivityType.saveToCameraRoll, UIActivityType.addToReadingList, UIActivityType.postToFlickr, UIActivityType.postToVimeo, UIActivityType.postToFacebook, UIActivityType.message, UIActivityType.postToWeibo]
    activityViewController.excludedActivityTypes = excludeActivities

    // present the view controller
    self.present(activityViewController, animated: true, completion: nil)


    // exclude some activity types from the list (optional)
    activityViewController.excludedActivityTypes = [ UIActivityType.airDrop, UIActivityType.postToFacebook ]

    // present the view controller
    self.present(activityViewController, animated: true, completion: nil)

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我用下面的代码解决它

if(temp_url != nil){
let activityViewController = UIActivityViewController(activityItems: [temp_url!], applicationActivities: nil)
        activityViewController.popoverPresentationController?.sourceView = self.view // so that iPads won't crash

        // exclude some activity types from the list (optional)
         let excludeActivities = [UIActivityType.airDrop, UIActivityType.print, UIActivityType.assignToContact, UIActivityType.saveToCameraRoll, UIActivityType.addToReadingList, UIActivityType.postToFlickr, UIActivityType.postToVimeo, UIActivityType.postToFacebook, UIActivityType.message, UIActivityType.postToWeibo]
        activityViewController.excludedActivityTypes = excludeActivities

        // present the view controller
        self.present(activityViewController, animated: true, completion: nil)
}

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我发现了这篇文章Swift：通过whatsapp共享mp3文件，但它对我也不起作用。那根本没有用。具体地说，详细地说，它是如何对你无效的？很抱歉，我更新了这篇文章。你应该在Swift3Hello中使用URL而不是NSURL，我改成了这个，但运气不好。var audioURL=URLfileURLWithPath:temp\u url！让activityViewController=UIActivityViewControlleractivityItems:[audioURL]，applicationActivities:Nil像那样使用强制展开是个坏主意。你是说临时url是这样吗？是的。使用强制展开通常不是一个好主意，因为如果基础可选项包含nil，则会崩溃。如果nil操作符在main中声明它，那么我称之为崩溃，所以我在其他3个函数中使用它。我不知道没有可选项怎么申报。可选项可以。使用强制展开选项！这通常是个坏主意，尤其是当你不明白它的作用时