HOWTO: How to Hide an Executable from the Taskbar

• Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a

SUMMARY

When a Visual FoxPro executable is running, it appears on the Windows or Windows NT 4.0 taskbar. This code provides a programmatic method of removing the Visual FoxPro executable from the taskbar while it is executing. This code emulates behavior similar to setting the ShowInTaskbar property to false (.F.) in Visual Basic.

MORE INFORMATION

This code does not work with Single Document Interface forms (SDI) because the mainhwnd() function gets the Windows handle (HWND) of the Visual FoxPro desktop. SW_HIDE serves to hide the executable from both the taskbar and the tasklist. However, the executable is not totally hidden from the operating system. When running an executable created with Visual FoxPro 3.0b, the Close Program window in Windows 95 and the Processes tab of the Windows NT 4.0 Task Manager both show the Vfp300.esl file. With a Visual FoxPro 5.0x executable running under Windows NT 4.0 or Windows 95, the executable's name appears in the Processes tab of the Windows NT Task Manager or in the Close Program window.

1. Create a project called Zhide and add a program named Zhide.prg.

2. In Zhide.prg, add the following code:

         DO FORM Zhide.scx
         READ EVENTS
   

   Zhide.prg should be marked as the main file of the project.

3. Add a form named Zhide to the project. Place the following code in the Load event of the form:

         Declare Integer ShowWindow in Win32API Integer hWnd, Integer nCmdShow
         SET LIBRARY TO c:\vfp3\foxtools.fll
         * The name of the Visual FoxPro folder may vary between machines.
   

4. Add a command button and place the following code in the Click event:

         #DEFINE SW_HIDE 0
         m.retval = ShowWindow(mainhwnd(), SW_HIDE)
   

5. Add a timer control to the form with an interval set to 10000 millisecond. Place the following code in the Timer event and close the form:

         m.retval = MessageBox("Click OK to quit", 0 + 48 + 0)
         #DEFINE SW_SHOW 5
         m.retval = ShowWindow(mainhwnd(), SW_SHOW)
         CLEAR EVENTS
         ThisForm.Release
   

   NOTE: This code is important. Without this code the window does not reappear and you cannot quit the application.

6. Build the executable and close Visual FoxPro. From Explorer, double- click Zhide.exe and within 10 seconds click the command button. The form should disappear from the taskbar and the tasklist. Check the tasklist by pressing the CTRL+ALT+DEL keys. In Windows 95 the Close Program window appears. In Windows NT 4.0 the Windows NT Security dialog box appears. Click Task Manager and then click the Applications tab. The Visual Foxpro executable is not listed in the Task Manager of the operating systems.

7. When the Messagebox appears, click OK to restore Visual Foxpro.