(Delphi ActiveX) Async Accept Socket Connection

Demonstrates how to get the connected client socket after accepting a connection asynchronously.

Chilkat for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

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
listenSocket: TChilkatSocket;
success: Integer;
maxWaitMs: Integer;
acceptTask: IChilkatTask;
connectedClient: TChilkatSocket;

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

listenSocket := TChilkatSocket.Create(Self);

// Bind to a port and listen.
// This example will listen at port 5555 and allows for a backlog
// of 25 pending connection requests.
success := listenSocket.BindAndListen(5555,25);
if (success <> 1) then
  begin
    Memo1.Lines.Add(listenSocket.LastErrorText);
    Exit;
  end;

// Start a background task to accept an incoming connection ...
maxWaitMs := 20000;
acceptTask := listenSocket.AcceptNextConnectionAsync(maxWaitMs);
acceptTask.Run();

// ...
// ...
// ...

// Imagine at this point the task has completed successfully,
// and a connection was accepted.  Here's how to get the connected socket...
connectedClient := TChilkatSocket.Create(Self);
success := connectedClient.LoadTaskResult(acceptTask);

// Here's how it works:  The AcceptNextConnection method would normally
// return a socket object when called synchronously.  When called asynchronously,
// it cannot do so because it returns the task object.  When the async method
// (running in a background thread) completes, the socket object that is the client
// connection is contained within the task object.
// 
// This can be generalized for any case where a Chilkat method returns an object.
// The async version of that method is such that the object returned in the background
// thread is contained within the task object.

// To get the result object, we create a new object instance of that type.
// In this case, we create a socket object (connectedClient).  There is a LoadTaskResult
// method in all Chilkat classes that can be a return value of an async method call.
// The LoadTaskResult method transfers the returned object from the task to the caller.
end;