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Build a terminal services client

{ "WINDOWS2000 SERVER" / "WINDOWS XP" terminal services are very important in a computer network: each client computer can emulate server's desktop by using a simple executable named "mstsc.exe". This executable uses the ActiveX control "MStscax" defined in "mstscax.dll". These files are automatically installed in Windows XP and Windows 2000 Server but not in Windows2000 Professional or Windows98. You can download the entire package containing these file at the following url: http://www.microsoft.com/windows2000/downloads/recommended/TSAC/tsmsi.asp?Lang= After downloading the executable "tsmsisetup.exe", run it to unpack. Now let's take into consideration the folder "System32": this is the folder containing "mstsc.exe" and "mstscax.dll". Now register the ActiveX control "MsTscAx": 1)Start->Run-> 2)type the following command line: regsvr32 <path to mstscax.dll>\mstscax.dll where <path to mstscax.dll> is the complete path to the file "mstscax.dll". In this article I will show you how to embed the ActiveX control "MsTscAx" in a Delphi application in order to build a substitute of "mstsc.exe". First of all you must import the ActiveX control "mstscax": in the Delphi IDE: 1)Component->Import ActiveX Control 2)Select "Microsoft Terminal Services Control" the class name will be "TMsTscAx" 3)Select the unit dir name and press "Create Unit": you have created the import Unit. 4)Create a package or select an existing one and add the created unit to this package Recompile the package and now delphi palette will contain (in the ActiveX tab if you haven't changed it in the importing process) the MstScax component. Now create a new Delphi project and add the Mstscax component to it. Let's go to analize the interesting properties of this new component: 1)Server: this is the IP of the Windows2000 Server computer whose desktop we want to emulate 2)BitmapPeristence: 1 if you want to cache Bitmaps or 0 otherwise 3)Compress: 1 if you want to cache data or 0 otherwise With the "Connect" method I open a terminal emulation session. With the "Disconnect" method I disconnect from a terminal emulation session but the session itself isn't closed on the server. Another important feature of "Client Terminal Service" is the ability to define a program that automatically run when the client machine opens a terminal emulation session. You can programatically achieve this target in this manner: Set_StartProgram(<Path to Exe>\<Exe filename>); Once defined an automatically running program, the client computer will see a remote desktop which is clear except for the presence of the program itself; this is useful if you want to restrict the operative range of your client computers to the program itself. When the program is closed, the connection is closed and the session on the windows 2000 server computer is closed. this is the code of my example project: } unit Main; interface uses Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, OleCtrls, ExtCtrls, StdCtrls, MSTSCLib_TLB;//the import Unit: substitute it with the name you assigned //during the import process if this is different to it type TForm1 = class(TForm) MsTscAx1: TMsTscAx; Panel1: TPanel; btConnect: TButton; procedure btConnectClick(Sender: TObject); //connection button procedure FormCreate(Sender: TObject); procedure FormClose(Sender: TObject; var Action: TCloseAction); procedure MsTscAx1Disconnected(Sender: TObject; DisconnectReason: Integer); procedure MsTscAx1Connecting(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.DFM} procedure TForm1.btConnectClick(Sender: TObject); begin MsTscAx1.Connect; end; procedure TForm1.FormCreate(Sender: TObject); begin Left := 0; Top := 0; Height := Screen.Height - 20; Width := Screen.Width; MsTscAx1.Server := '1.2.3.4'; //substitute it with the IP Address of your server with MsTscAx1.AdvancedSettings do begin BitmapPeristence := 1;//enable bitmap cache Compress := 1;//enable data cache end; with MsTscAx1.SecuredSettings do begin Set_StartProgram('C:\Sviluppo\Delphi\DbBrowser.exe'); //the program I want to run end; end; procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction); begin if not btConnect.Enabled then //I must close the automatically running program before closing //my terminal emulation program begin MessageDlg('Close "DbBrowser.exe" before closing the application!', mtInformation, [mbOK], 0); Action := caNone; end; end; procedure TForm1.MsTscAx1Disconnected(Sender: TObject; DisconnectReason: Integer); begin btConnect.Enabled := True; end; procedure TForm1.MsTscAx1Connecting(Sender: TObject); begin btConnect.Enabled := False; end; end. { In order to run this application in another computer you must copy the file "mstscax.dll" on the target computer and register it with "regsvr32" as shown at the beginning of this article. You can automate this process by embedding the file in your executable, etc.. Carlo Pasolini, Riccione(Italy), ccpasolini@libero.it }