Sensing when a handle is no longer active

[William Fletcher]

After an asynchronous SHELL to another app in Windows 95, how can I detect when the app is no longer executing/active?

MyHandle = SHELL(pgm)

e.g. is there an Api I can use to see if "MyHandle" is no longer active?

TIA

[Eric Pearson]

The GetExitCodeProcess API will return %STILL_ACTIVE (&h0103&) as long as an app is running, but you need the Process Handle to use it and the PB/DLL docs say that the SHELL function returns an Instance Handle. There may be an API to get the Process Handle from an Instance Handle... I can't remember. If you can't figure out how to do it, it might be easier to use CreateProcess instead of SHELL, since CreateProcess returns a Process Handle directly.

Or, if the app that you are trying to detect has (or can have) a unique string in its title bar, you could use the FindWindow API function to see if the window still exists.

-- Eric

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[This message has been edited by Eric Pearson (edited May 11, 2000).]

[Eric Pearson]

I just performed a quick test and it appears that the PB/DLL SHELL function returns a Process ID, not an Instance Handle. I have posted a message containing a sample program in the Source Code Forum.

-- Eric

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[Semen Matusovski]

Simple alternative - thread

   #Compile Exe
   #Register None
   #Dim All
   #Include "Win32Api.inc"
   Global hDlg As Long
   Function MyThread (ByVal x As Long) As Long
      Shell "Notepad.Exe"
      Control Set Text hDlg, 101, "Finished"
   End Function
   Function PbMain () As Long
      Local x As Long, idThread As Long
      Thread Create MyThread(x) To idThread
      Thread Close idThread To idThread
      Dialog New 0, "Hello",,, 200, 80, %WS_SYSMENU, %WS_EX_TOPMOST To hDlg
      Control Add TextBox, hDlg, 101, "", 10, 10, 180, 50
      Dialog Show Modal hDlg
   End Function

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[William Fletcher]

Thank you Semen - because of my circumstances, your tip did the trick exactly. I needed to make a conditional DOS window close after running a Win95 utility (sometimes it appears, sometimes not), and the extra thread did the trick perfectly.

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