From the September 2011 Issue of Prestwood eMag

Delphi Language Details: Using SetWindowLong in Delphi By Mike Prestwood

Posted 22 years ago on 11/22/2002 Take Away: Use SetWindowLong to hide your application.  Tags: Delphi , setwindowlong , getwindowlong KB100068

Q. In Delphi, how do you hide an application from the list with the start-menu-button on it?

A. Are you talking about hiding your application from the task list? If so, use the SetWindowLong procedure to change the application type from application window to a tool window.

Here's some code:

code:

---

program Project1;

uses
  Forms,
  Unit1 in 'Unit1.pas' {Form1},
  Windows;

{$R *.RES}

//Declare a var to retrieve current window information
var
  ExtendedStyle : Integer;

begin
  Application.Initialize;

  //Get the Extended Styles of the Application, 
  //by passing its
  //handle to GetWindowLong
  ExtendedStyle := GetWindowLong(Application.Handle, 
                   GWL_EXSTYLE);

  //Now, set the Extended Style by doing a 
  //bit masking operation.
  //OR in the WS_EX_TOOLWINDOW bit, and AND out 
  //the WS_EXAPPWINDOW bit
  //This effectively converts the application from 
  //an App Windows to a
  //Tool Window.
  SetWindowLong(Application.Handle, GWL_EXSTYLE,
     ExtendedStyle OR WS_EX_TOOLWINDOW
     AND NOT WS_EX_APPWINDOW);

  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

---

Comments

KB Post Contributed By Mike Prestwood:

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