异步FTP上传文件列表

Question

I'm trying to loop through a list of images and ftp them to a server. It's partially working except for it is still blocking my UI thread. Even though my ftp function is async, I'm guessing because my calling method is not, I'm not getting the results I'm looking for. Here's what I got. What am I doing wrong?

   public void UploadPictures()
    {
        //loop through each picture and upload
        for (int i = 0; i < this.items.Count; i++) {

            byte[] bytes;
            if (System.IO.Path.GetExtension (this.items [i].FileName.ToUpper()) == ".JPG") {
                using (var imageData = this.items[i].Image.AsJPEG())
                {
                    bytes = new byte[imageData.Length];
                    Marshal.Copy(imageData.Bytes, bytes, 0, Convert.ToInt32(imageData.Length));
                }
                var test=UploadPhoto(bytes,  this.items[i].FileName);

            }

            if (System.IO.Path.GetExtension (this.items [i].FileName.ToUpper()) == ".PNG") {
                using (var imageData = this.items[i].Image.AsPNG())
                {
                    bytes = new byte[imageData.Length];
                    Marshal.Copy(imageData.Bytes, bytes, 0, Convert.ToInt32(imageData.Length));
                }
                var test=UploadPhoto(bytes,  this.items[i].FileName);

            }


        }



    }



    public static async Task<string> UploadPhoto(byte[] photoBytes,  string filename)
    {
        FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create("ftp://XXXXXXXX/" + filename);
        request.Method = WebRequestMethods.Ftp.UploadFile;
        request.Credentials = new NetworkCredential ("user", "pass"); 
        request.UseBinary = true;

        request.ContentLength = photoBytes.Length;
        using (Stream s = request.GetRequestStream())
        {
            s.Write(photoBytes, 0,photoBytes.Length);
        }
        WebResponse ftpResp = await (Task<WebResponse>)request.GetResponseAsync ();

        return ftpResp.ToString();

    }

Answer 1

马克UploadPictures为async和await上UploadPhoto 。

Answer 2

So I called my UploadPictures function using Task run and that worked. Not sure if thats the most correct way to do it.

   Task.Run( () =>
                    {
                        UploadPictures();
            });