(MFC) Send Email Asynchronously using a Task

Send email asynchronously using the task object. Any Chilkat method (in any class/object) that involves network communications or lengthy processing will have an asynchronous version of the method. The asynchronous method has the same name as the synchronous method, but ends in "Async" and returns a Task object. The Task object can be run asynchronously on Chilkat's background thread pool.

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See Also: Using MFC CString in Chilkat

#include <CkMailMan.h>
#include <CkEmail.h>
#include <CkTask.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // The mailman object is used for sending and receiving email.
    CkMailMan mailman;

    // Set the SMTP server and any required settings.
    mailman.put_SmtpHost("smtp.mymailserver.com");
    mailman.put_SmtpUsername("myLogin");
    mailman.put_SmtpPassword("myPassword");
    mailman.put_StartTLS(true);

    // Create a new email object
    CkEmail email;

    email.put_Subject("This is a test");
    email.put_Body("This is a test");
    email.put_From("Chilkat Support <support@chilkatsoft.com>");
    bool success = email.AddTo("Chilkat Admin","admin@chilkatsoft.com");

    // Call the async version of the SendEmail method to return a task object.
    // The task object is loaded, but is in the Inert state -- meaning it is
    // not yet scheduled to run on Chilkat's background thread pool.
    CkTask *task = mailman.SendEmailAsync(email);
    if (mailman.get_LastMethodSuccess() == false) {
        strOut.append(mailman.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Schedule the task for running on the thread pool.  This changes the task's state
    // from Inert to Live.
    success = task->Run();
    if (success != true) {
        strOut.append(task->lastErrorText());
        strOut.append("\r\n");
        delete task;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The application is now free to do anything else
    // while the email is being sent.

    // For this example, we'll simply sleep and periodically
    // check to see if the SendEmail if finished.  While checking
    // however, we'll report on the progress.
    int curPctDone = 0;
    while (task->get_Finished() != true) {

        if (task->get_PercentDone() != curPctDone) {
            curPctDone = task->get_PercentDone();
            strOut.appendInt(curPctDone);
            strOut.append(" percent done");
            strOut.append("\r\n");
        }

        // Sleep 100 ms.
        task->SleepMs(100);

    }

    // A finished task could be one that was canceled, aborted, or truly finished.  

    // If the task was "canceled", it was canceled prior to actually starting.  This could
    // happen if the task was canceled while waiting in a thread pool queue to be scheduled by Chilkat's
    // background thread pool scheduler.  

    // If the task was "aborted", it indicates that it was canceled while running in a background thread.  
    // The ResultErrorText will likely indicate that the task was aborted.

    // If the task "completed", then it ran to completion, but the actual success/failure of the method
    // is determined by the result obtained via a GetResult* method.  (A "completed" task will
    // have a StatusInt equal to 7.   If the task finished, but was not completed, then it must've
    // been aborted or canceled:
    if (task->get_StatusInt() != 7) {
        strOut.append("Task did not complete.");
        strOut.append("\r\n");
        strOut.append("task status: ");
        strOut.append(task->status());
        strOut.append("\r\n");
        delete task;
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The SendEmail method returns a boolean.  Therefore, after the task is finished,
    // we can get the boolean result by calling GetResultBool.  This is the return value had
    // we called SendEmail synchronously.
    success = task->GetResultBool();
    if (success != true) {
        // The task's ResultErrorText contains what would have been in the LastErrorText property had
        // the SendEmail method been called synchronously.
        strOut.append(task->resultErrorText());
        strOut.append("\r\n");
    }
    else {
        strOut.append("Email sent asynchronously.");
        strOut.append("\r\n");
    }

    delete task;

    success = mailman.CloseSmtpConnection();
    if (success != true) {
        strOut.append("Connection to SMTP server not closed cleanly.");
        strOut.append("\r\n");

    }



    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }