CODEWITHSUNDEEP
c#.netwpfasynchronous
user1358072
user1358072

Reputation: 447

how to implement while loop for processing when clicking

I hope you can help me with this problem. When I click a Email button, it takes few seconds to process before sending successfully. I need to put process image on but how to implement with "while" loop for processing.
Here is code: i think i should implement with client.Send(msg); for processing. How does it work? I will appreciate your example code. Thanks! (I am using C# and WPF)

private void BtnSendEmailClick(object sender, RoutedEventArgs e)
{
        SmtpClient client = null;
        MailMessage msg = null;

        try
        {

            msg = new MailMessage
            {
                From = new MailAddress("[email protected]", "Me Hotmail")
            };

            msg.To.Add(txtEmailAddress.Text);


            msg.Priority = MailPriority.High;
            msg.Subject = "Blah blah";


            msg.Body =

                "<!DOCTYPE html><html lang='en' xmlns='http://www.w3.org/1999/xhtml'>" +
                "<head> </head>" +
                "<body>" +
                "<h3>Message</h3>" +
                "<p>" + lblEmailMessage.Content + "</p>" +
                "</body>" +
                "</html>";

            msg.IsBodyHtml = true;

            client = new SmtpClient
            {
                Host = "smtp.live.com",
                Port = 25,
                EnableSsl = true,
                UseDefaultCredentials = false,
                Credentials = new NetworkCredential("[email protected]", "password"),
                DeliveryMethod = SmtpDeliveryMethod.Network
            };

              //how to implement while loop for processing
              client.Send(msg);

              lblMessage.Content = "Successfully sent to your Mail!";

        }
        catch (Exception ex)
        {
            lblMessage.Content = ex.Message;

        }

    }

Upvotes: 0

Views: 179

Answers (2)

Jeremy Wiebe
Jeremy Wiebe

Reputation: 3963

Are you wanting to display an image to indicate that the program is doing something (progress indicator)?

In that case you need to do the work of sending the email on a separate thread. You can do this in several ways. The easiest (if you are using .NET 4) is to use the await and async keywords. Simply display the image before starting your work. You'll need to extract the code that actually sends the email into a new method also. Like this:

private void BtnSendEmailClick(object sender, RoutedEventArgs e)
{
    // Display progress image
    progressImage.Visibility = System.Windows.Visibility.Visible;

    string errorMessage = await SendEmail();

    if (errorMessage == null) 
    {
        lblMessage.Content = "Successfully sent to your Mail!";
    }
    else
    {
        lblMessage.Content = errorMessage;
    }

    progressImage.Visibility = System.Windows.Visibility.Hidden;
}

private async Task<string> SendEmail()
{
    try
    {
        var msg = new MailMessage
        {
            From = new MailAddress("[email protected]", "Me Hotmail")
        };

        msg.To.Add(txtEmailAddress.Text);
        msg.Priority = MailPriority.High;
        msg.Subject = "Blah blah";
        msg.Body =
            "<!DOCTYPE html><html lang='en' xmlns='http://www.w3.org/1999/xhtml'>" +
            "<head> </head>" +
            "<body>" +
            "<h3>Message</h3>" +
            "<p>" + lblEmailMessage.Content + "</p>" +
            "</body>" +
            "</html>";
        msg.IsBodyHtml = true;

        var client = new SmtpClient
        {
            Host = "smtp.live.com",
            Port = 25,
            EnableSsl = true,
            UseDefaultCredentials = false,
            Credentials = new NetworkCredential("[email protected]", "password"),
            DeliveryMethod = SmtpDeliveryMethod.Network
        };

        //how to implement while loop for processing
        client.Send(msg);

        return "Successfully sent to your Mail!";
    }
    catch (Exception ex)
    {
        return ex.Message;
    }
}

One final note: Be sure that you don't touch any UI components in your 'async' method as there is no guarantee that the code will be running on the UI thread. If you need more information returned from the async method you'll have to create a custom structure to contain the result and return it from that SendEmail() method.

Upvotes: 0

Rob Lyndon
Rob Lyndon

Reputation: 12651

You will need to return instantly, and use a BackgroundWorker to send the email. Once it is finished, you can use the Dispatcher to notify the GUI. See http://msdn.microsoft.com/en-us/magazine/cc163328.aspx for more details.

See also How to use WPF Background Worker.

Upvotes: 1

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