Delphi DLL

Async Progress Info Log

See more Async Examples

Demonstrates checking for progress info updates when running a task asynchronously. Delphi DLL

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, MailMan, Task, Email;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
mailman: HCkMailMan;
email: HCkEmail;
task: HCkTask;
curPctDone: Integer;
name: PWideChar;
value: PWideChar;

begin
success := False;

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

success := False;

// The mailman object is used for sending and receiving email.
mailman := CkMailMan_Create();

// Set the SMTP server and any required settings.
CkMailMan_putSmtpHost(mailman,'smtp.mymailserver.com');
CkMailMan_putSmtpUsername(mailman,'myLogin');
CkMailMan_putSmtpPassword(mailman,'myPassword');
CkMailMan_putStartTLS(mailman,True);

// Create a new email object
email := CkEmail_Create();

CkEmail_putSubject(email,'This is a test');
CkEmail_putBody(email,'This is a test');
CkEmail_putFrom(email,'Chilkat Support <support@chilkatsoft.com>');
success := CkEmail_AddTo(email,'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.
task := CkMailMan_SendEmailAsync(mailman,email);
if (CkMailMan_getLastMethodSuccess(mailman) = False) then
  begin
    Memo1.Lines.Add(CkMailMan__lastErrorText(mailman));
    Exit;
  end;

// Before starting the task, tell it to keep an in-memory log of what would've been
// ProgressInfo event callbacks.
CkTask_putKeepProgressLog(task,True);

// Schedule the task for running on the thread pool.  This changes the task's state
// from Inert to Live.
success := CkTask_Run(task);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkTask__lastErrorText(task));
    CkTask_Dispose(task);
    Exit;
  end;

// 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.
curPctDone := 0;

while CkTask_getFinished(task) <> True do
  begin

    if (CkTask_getPercentDone(task) <> curPctDone) then
      begin
        curPctDone := CkTask_getPercentDone(task);
        Memo1.Lines.Add(IntToStr(curPctDone) + ' percent done');
      end;

    // Check the progress info log.
    // Emit any log entries..
    while (CkTask_getProgressLogSize(task) > 0) do
      begin
        // Get the 1st entry, emit it, and then remove it..
        name := CkTask__progressInfoName(task,0);
        value := CkTask__progressInfoValue(task,0);
        Memo1.Lines.Add(name + ': ' + value);
        CkTask_RemoveProgressInfo(task,0);
      end;

    // Sleep 100 ms.
    CkTask_SleepMs(task,100);

  end;

// Just in case there are any remaining entries...
while (CkTask_getProgressLogSize(task) > 0) do
  begin
    // Get the 1st entry, emit it, and then remove it..
    name := CkTask__progressInfoName(task,0);
    value := CkTask__progressInfoValue(task,0);
    Memo1.Lines.Add(name + ': ' + value);
    CkTask_RemoveProgressInfo(task,0);
  end;

// 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 (CkTask_getStatusInt(task) <> 7) then
  begin
    Memo1.Lines.Add('Task did not complete.');
    Memo1.Lines.Add('task status: ' + CkTask__status(task));
    CkTask_Dispose(task);
    Exit;
  end;

// 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 := CkTask_GetResultBool(task);
if (success <> True) then
  begin
    // The task's ResultErrorText contains what would have been in the LastErrorText property had
    // the SendEmail method been called synchronously.
    Memo1.Lines.Add(CkTask__resultErrorText(task));
  end
else
  begin
    Memo1.Lines.Add('Email sent asynchronously.');
  end;

CkTask_Dispose(task);

success := CkMailMan_CloseSmtpConnection(mailman);
if (success <> True) then
  begin
    Memo1.Lines.Add('Connection to SMTP server not closed cleanly.');

  end;

CkMailMan_Dispose(mailman);
CkEmail_Dispose(email);

end;