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.

Download Chilkat Socket ActiveX

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATSOCKETLib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
listenSocket: TChilkatSocket;
success: Integer;
connectedSocket: IChilkatSocket;

begin
listenSocket := TChilkatSocket.Create(Self);

success := listenSocket.UnlockComponent('Anything for 30-day trial');
if (success <> 1) then
  begin
    ShowMessage('Failed to unlock component');
    Exit;
  end;

//  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 <> 1) then
  begin
    ShowMessage(listenSocket.LastErrorText);
    Exit;
  end;

//  Get the next incoming connection
//  Wait a maximum of 20 seconds (20000 millisec)

connectedSocket := listenSocket.AcceptNextConnection(20000);
if (connectedSocket = nil ) then
  begin
    ShowMessage(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
    ShowMessage(connectedSocket.LastErrorText);

    Exit;
  end;

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

ShowMessage('success!');
end;