(Delphi ActiveX) TCP Socket Connect through HTTP Proxy

Demonstrates how to connect through an HTTP proxy server.

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
socket: TChilkatSocket;
hostname: WideString;
ssl: Integer;
maxWaitMillisec: Integer;
success: Integer;
receivedMsg: WideString;

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

socket := TChilkatSocket.Create(Self);

// To connect through an HTTP proxy, set the HttpProxyHostname
// and HttpProxyPort properties to the hostname (or IP address)
// and port of the HTTP proxy.  Typical port numbers used by
// HTTP proxy servers are 3128 and 8080.
socket.HttpProxyHostname := 'www.my-http-proxy.com';
socket.HttpProxyPort := 3128;

// Important:  Your HTTP proxy server must allow non-HTTP
// traffic to pass.  Otherwise this does not work.

// Connect (via the HTTP proxy) to port 5555 of 192.168.1.108.
// hostname may be a domain name or IP address.
hostname := '192.168.1.108';
ssl := 0;
maxWaitMillisec := 20000;
success := socket.Connect(hostname,5555,ssl,maxWaitMillisec);
if (success <> 1) then
  begin
    Memo1.Lines.Add(socket.LastErrorText);
    Exit;
  end;

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

// The ficticious server (in this example) is going to send a "Hello World!" 
// message.  Read it:
receivedMsg := socket.ReceiveString();
if (socket.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(socket.LastErrorText);
    Exit;
  end;

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

Memo1.Lines.Add(receivedMsg);
end;