Delphi DLL

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 DLL

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
socket: HCkSocket;
maxWaitMs: Integer;
task: HCkTask;

begin
success := False;

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

socket := CkSocket_Create();

// 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 := CkSocket_ConnectAsync(socket,'amazonbladflakjsdflksadjf.com',443,True,maxWaitMs);
if (CkSocket_getLastMethodSuccess(socket) = False) then
  begin
    Memo1.Lines.Add(CkSocket__lastErrorText(socket));
    Exit;
  end;
// Start the background thread to run the task.
success := CkTask_Run(task);
if (not success) then
  begin
    Memo1.Lines.Add(CkTask__lastErrorText(task));
    CkTask_Dispose(task);
    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 CkTask_getFinished(task) <> True do
  begin
    // Sleep 1 ms.
    CkTask_SleepMs(task,1);
  end;

// If the task completed, it means the method (in this case the Connect method) was called and returned success or failure.
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;

// Get the success/failure of the Connect
// (This is the return value of the Connect method had it been called synchronously)
success := CkTask_GetResultBool(task);
if (success = False) 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(CkTask__resultErrorText(task));
  end
else
  begin
    Memo1.Lines.Add('Connect succeeded.');
  end;

CkTask_Dispose(task);

CkSocket_Dispose(socket);

end;