MFMessageComposser每当我发送附件时都会导致内存泄漏

Question

我有一个Swift 4.2脚本，可以使用MFMessageCompose发送附件视频。我注意到每次发送视频时，内存使用量都会增加。当我退出MessageView时，内存不会释放。每次我使用MFMessageController发送附件时，内存都会增加。我运行了调试程序，它通知我IOSurface中的内存泄漏。我按下按钮时会打开带有附件的MFMessage视图。即使我取消了它，内存也会显示增加。当我按下此按钮时，内存只会跳到附件的大小。下面提供了我正在使用的代码。有人可以帮我弄清楚如何释放此内存，以便我的应用在多次发送后不会崩溃吗？

//从UIViewController上的按钮开始发送操作     @IBAction func sendMessage（_ sender：Any）{

    func sendSMS(attachment: String) {
        }
    }

    if let vid = self.selectedVideo {
        self.titleLabel.text = vid.videoTitle
        self.descriptionLabel.text = vid.videoDescription
        let requestObj2 = (vid.videoId + ".mp4")
        sendSMS(attachment: requestObj2)

    // Check if the device is capable of sending text message
            guard MFMessageComposeViewController.canSendText() else {
            let alertMessage = UIAlertController(title: "SMS unavailable", message: "Your device is not capable of sending SMS.", preferredStyle: .alert)
            alertMessage.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
            present(alertMessage, animated: true, completion: nil)
            return
        }

        // Prefill the SMS
        let messageController = MFMessageComposeViewController()
        messageController.messageComposeDelegate = self
        messageController.recipients = [" "]
        messageController.body = " "
        print("prefill the SMS")

        //Adding file attachment
        let fileparts = requestObj2.components(separatedBy: ".")
        let filename = fileparts[0]
        let fileExtension = fileparts[1]
        let filePath = Bundle.main.path(forResource: filename, ofType: fileExtension)
        let fileUrl = NSURL.fileURL(withPath: filePath!)
       messageController.addAttachmentURL(fileUrl, withAlternateFilename: nil)

        //Present message view controller on screen
        present(messageController, animated: true, completion: nil)
        print("present message view")

        return