Form Method on another thread not invoking the events.

Question

I am trying to achieve an update form.

I use a library to open a form when there is an updated file and download using edtFTPNet

In the form I pass the FTP object and start download, in FormLoad i handle two events and i use Thread to StartDownload(). My two events never invoking, i use them to set a progress bar.

public partial class UpdateProgressForm : XtraForm
{
    public FTPConnection FtpConn { get; set; }
    public string UpdateFileName { get; set; }

    public UpdateProgressForm()
    {
        InitializeComponent();
    }

    private void OnLoad(object sender, EventArgs e)
    {
        FtpConn.Downloading += FileDownLoading;
        FtpConn.BytesTransferred += FileBytesTransfered;
    }

    private void FileDownLoading(object sender, FTPFileTransferEventArgs e)
    {
        progressBar.Properties.Maximum = (int) e.FileSize;
    }

    private void FileBytesTransfered(object sender, BytesTransferredEventArgs e)
    {
        progressBar.Position = (int) e.ByteCount;
    }

    public void StartDownload()
    {
        FtpConn.DownloadFile(@".\" + UpdateFileName, UpdateFileName);
    }

    private void OnShown(object sender, EventArgs e)
    {
        Thread tt = new Thread(StartDownload) {IsBackground = true};
        tt.Start();
    }
}

Library method calling the Form:

private void DownloadUpdateFile(string updateFileName)
{
    using (ProgressForm = new UpdateProgressForm { FtpConn = FtpConn, UpdateFileName = updateFileName })
    {
        ProgressForm.ShowDialog();
    }
}

Any help? Thank you.

Answer 1

Are you sure that the event handlers are not invoked? I think your problem rather is that you try to update the progress bar on the worker thread on which the event handlers are invoke (which is not the thread on which the GUI was created). You should make sure that the GUI updates are performed on the correct thread:

private void FileDownLoading(object sender, FTPFileTransferEventArgs e)
{
    progressBar.Invoke((MethodInvoker) delegate 
    { 
        progressBar.Properties.Maximum = (int) e.FileSize;
    });
}

Answer 2

1. Take a look in the designer and make sure you subscribe to those events
2. Make sure you Instanciate and Show the from from the Main Thread.