c# - 异步 FTP 上传

Question

我怎样才能使这段代码在异步下面，我不知道异步如何与 FTP 上传一起工作。我尝试了很多方法，但如果您上传文件，我不知道将“等待”放在哪里。

public static async void SelectRectangle(Point SourcePoint, Point DestinationPoint, Rectangle SelectionRectangle, string FilePath)
{
    using (Bitmap bitmap = new Bitmap(SelectionRectangle.Width, SelectionRectangle.Height))
    {
        using (Graphics g = Graphics.FromImage(bitmap))
        {

            g.CopyFromScreen(SourcePoint, DestinationPoint, SelectionRectangle.Size);

            FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(Properties.Settings.Default.ftphost + Properties.Settings.Default.ftppath + FilePath + "." + Properties.Settings.Default.extension_plain);
            request.Method = WebRequestMethods.Ftp.UploadFile;
            request.Credentials = new NetworkCredential(Properties.Settings.Default.ftpuser, Properties.Settings.Default.ftppassword);
            request.UseBinary = true;

            bitmap.Save(request.GetRequestStream(), ImageFormat.Png);
        }
    }
}

乔里。

Answer 1

您需要创建方法async，然后使用await 进行任何异步操作。您似乎只有其中之一，因此以下应该有效:

public static async Task SelectRectangle(Point SourcePoint, Point DestinationPoint, Rectangle SelectionRectangle, string FilePath)
{
    using (Bitmap bitmap = new Bitmap(SelectionRectangle.Width, SelectionRectangle.Height))
    {
        using (Graphics g = Graphics.FromImage(bitmap))
        {

            g.CopyFromScreen(SourcePoint, DestinationPoint, SelectionRectangle.Size);

            FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(Properties.Settings.Default.ftphost + Properties.Settings.Default.ftppath + FilePath + "." + Properties.Settings.Default.extension_plain);
            request.Method = WebRequestMethods.Ftp.UploadFile;
            request.Credentials = new NetworkCredential(Properties.Settings.Default.ftpuser, Properties.Settings.Default.ftppassword);
            request.UseBinary = true;

            Stream rs = await request.GetRequestStreamAsync();
            bitmap.Save(rs, ImageFormat.Png);
        }
    }
}