Delphi ActiveX

Get the LastErrorText for an Asynchronous Method Call

See more Async Examples

Demonstrates how to get the LastErrorText information for a Chilkat method called asynchronously. Delphi ActiveX

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
socket: TChilkatSocket;
maxWaitMs: Integer;
task: IChilkatTask;

begin
success := 0;

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

socket := TChilkatSocket.Create(Self);

// The Async call simply creates the task.  The "Connect" method has not yet been called.
maxWaitMs := 5000;
// Let's intentionally cause this connect to fail by giving it an invalid domain..
task := socket.ConnectAsync('amazonbladflakjsdflksadjf.com',443,1,maxWaitMs);
if (socket.LastMethodSuccess = 0) then
  begin
    Memo1.Lines.Add(socket.LastErrorText);
    Exit;
  end;
// Start the background thread to run the task.
success := task.Run();
if (not success) then
  begin
    Memo1.Lines.Add(task.LastErrorText);

    Exit;
  end;

// The application is now free to do anything else

// For this example, we'll simply sleep and periodically
// check to see if the Socket Connect if finished.
while task.Finished <> 1 do
  begin
    // Sleep 1 ms.
    task.SleepMs(1);
  end;

// If the task completed, it means the method (in this case the Connect method) was called and returned success or failure.
if (task.StatusInt <> 7) then
  begin
    Memo1.Lines.Add('Task did not complete.');
    Memo1.Lines.Add('task status: ' + task.Status);

    Exit;
  end;

// Get the success/failure of the Connect
// (This is the return value of the Connect method had it been called synchronously)
success := task.GetResultBool();
if (success = 0) then
  begin
    // Get the LastErrorText for the Connect method call.
    // Had we called Connect synchronously, we would've simply accessed the socket object's LastErrorText property.
    // Instead, we get the task object's ResultErrorText.
    Memo1.Lines.Add(task.ResultErrorText);
  end
else
  begin
    Memo1.Lines.Add('Connect succeeded.');
  end;
end;