HTTP Asynchronous Upload

The Chilkat Upload component is freeware. This example demonstrates how to HTTP upload one or more files asynchronously in a background thread and monitor the progress (and potentially abort the upload prior to it finishing). Formal support for the Chilkat Upload component is included with a "Chilkat Bundle" purchase.

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//  
// This example demonstrates how to HTTP upload one or more files
// asynchronously in a background thread.
private void button2_Click(object sender, EventArgs e)
{
    Chilkat.Upload upload = new Chilkat.Upload();

    // To upload more than one file, call AddFileReference multiple times --
    // once for each file to be uploaded.

    // The formElementName is arbitrary, and can be anything.  
    string formElementName = "file1";
    // The localFilename is a file that exists on your local filesystem.
    string localFilename = "hamlet.xml";
    upload.AddFileReference(formElementName, localFilename);

    // The Hostname and Path properties specify the server-side
    // page/program/script/CGI that will recieve and process the upload.
    upload.Hostname = "www.freeaspupload.net";
    upload.Path = "/freeaspupload/testUpload.asp";

    // Start the upload in a background thread.
    bool success = upload.BeginUpload();
    if (success == false)
    {
        textBox1.Text = upload.LastErrorText;
        return;
    }

    // Note: When doing asynchronous uploads, there are no event callbacks.
    // Event callbacks only occur when doing synchronous uploads via the 
    // BlockingUpload method.


    // Wait for the upload to finish.
    // Update the progress as we wait.
    while (upload.UploadInProgress)
    {
        // We can abort the upload at any point by calling:
        // upload.AbortUpload();

        // Display the percentage complete and the number of bytes uploaded so far..
        label1.Text = Convert.ToString(upload.PercentUploaded) + "% complete";
        label2.Text = Convert.ToString(upload.NumBytesSent) + " bytes uploaded...";

        // Show the percentage completion in a progress bar.
        progressBar1.Value = (int)upload.PercentUploaded;

        // The total upload size will become set after the upload begins:
        label3.Text = "Total Upload Size (in bytes) = " + Convert.ToString(upload.TotalUploadSize);

        // Sleep 1/10th of a second.
        upload.SleepMs(100);

        // Handle UI events.
        System.Windows.Forms.Application.DoEvents();
    }

    // Did the upload succeed?
    if (upload.UploadSuccess)
    {
        MessageBox.Show("Success!");
    }
    else
    {
        MessageBox.Show(upload.LastErrorText);
    }


}