(Delphi ActiveX) Accept Connection on Socket

Demonstrates how to create a TCP/IP socket, listen on a port, accept an incoming connection, and send a "Hello World" message to the client.

Note: This example requires Chilkat v11.0.0 or greater.

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
success: Integer;
listenSocket: TChilkatSocket;
connectedSocket: TChilkatSocket;

begin
success := 0;

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

listenSocket := TChilkatSocket.Create(Self);

// Bind to a port and listen for incoming connections:
// This example will listen at port 5555 and allows for a backlog
// of 25 pending connection requests.
success := listenSocket.BindAndListen(5555,25);
if (success = 0) then
  begin
    Memo1.Lines.Add(listenSocket.LastErrorText);
    Exit;
  end;

// Get the next incoming connection
// Wait a maximum of 20 seconds (20000 millisec)
connectedSocket := TChilkatSocket.Create(Self);
success := listenSocket.AcceptNext(20000,connectedSocket.ControlInterface);
if (success = 0) then
  begin
    Memo1.Lines.Add(listenSocket.LastErrorText);
    Exit;
  end;

// Set maximum timeouts for reading an writing (in millisec)
connectedSocket.MaxReadIdleMs := 10000;
connectedSocket.MaxSendIdleMs := 10000;

// Send a "Hello World!" message to the client:
success := connectedSocket.SendString('Hello World!');
if (success <> 1) then
  begin
    Memo1.Lines.Add(connectedSocket.LastErrorText);
    Exit;
  end;

// Close the connection with the client.
// Wait a max of 20 seconds (20000 millsec)
success := connectedSocket.Close(20000);

Memo1.Lines.Add('success!');
end;