Watch for another app to end

[nishantp]

I have been trying to figure this out for some time now...I want my first app (app A) to be able to detect when my other app(App B) has ended, or is no longer running for any reason. For instance, if app A exits or is ended, i want app B to be able to detect it. How would i do that?

[Mikelo2k]

One way i can see of doing that is:
1. Make a timer on App A which uses an API to check if App B exists (is running)
2. Same as above except App B checking App A this time.

Thanx,
Mikelo2k

[Mikelo2k]

Put this in the Declarations (module):

Public Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As Long

---------------------------------------

1. First find out the class name of your APP (for notepad it's "Notepad")
2. Repeat for the Other App.
(If you want to knwo how to find out the class name jsut ask)
3. Then you should put in a timer:
If (FindWindow(ClassName,Caption\Title of the app) = 0 then
.. 'Re-open your app or notify user ..
End If

Hope that is clear.

Thanx,
Mikelo2k

[nishantp]

Originally posted by Mikelo2k
One way i can see of doing that is:
1. Make a timer on App A which uses an API to check if App B exists (is running)
2. Same as above except App B checking App A this time.

Thanx,
Mikelo2k

I knew that...its just I have no idea which API would be best for something like this...

[nishantp]

*cough*

[nishantp]

Anyone got any ideas?

[DaoK]

Add winsock ocx with the ip 127.0.0.1 and if he can connect then put a variable to a number and if he lost connection ( stop other program ) to an other number.

Algo:
1-
ProgA connected
MyVariable = 0
ProgB not connected
2-
ProgA connected
MyVariable = MyVariable +1 ' // (1)
ProgB connected
3-
ProgA connected
MyVariable = MyVariable +1 ' // ( 2 )
ProgB not connected
If MyVariable = 2 then not connected

It's just an idea...using Winsock.

[nishantp]

Wouldnt the Winsock method conflict with other programs using 127.0.0.1 for any reason? I would rather not use Winsock...perhaps an API...anyone know if WaitForSingleObject can be used for that?

[DaoK]

well it will not be conflict if you are not using the same port. Maybe an API can do the job.

[Nucleus]

If you shell app A from app B then I guess you can.

I would suggest putting the following code in an ax exe (to allow async execution) alternatively read up on the switches for the api calls which may allow you to execute the code asynchronously without using an ax exe.

See here for detailed explanation: http://support.microsoft.com/support.../Q129/7/96.ASP
From the above MSDN link:

Private Type STARTUPINFO
      cb As Long
      lpReserved As String
      lpDesktop As String
      lpTitle As String
      dwX As Long
      dwY As Long
      dwXSize As Long
      dwYSize As Long
      dwXCountChars As Long
      dwYCountChars As Long
      dwFillAttribute As Long
      dwFlags As Long
      wShowWindow As Integer
      cbReserved2 As Integer
      lpReserved2 As Long
      hStdInput As Long
      hStdOutput As Long
      hStdError As Long
   End Type
 
   Private Type PROCESS_INFORMATION
      hProcess As Long
      hThread As Long
      dwProcessID As Long
      dwThreadID As Long
   End Type
 
   Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal _
      hHandle As Long, ByVal dwMilliseconds As Long) As Long
 
   Private Declare Function CreateProcessA Lib "kernel32" (ByVal _
      lpApplicationName As String, ByVal lpCommandLine As String, ByVal _
      lpProcessAttributes As Long, ByVal lpThreadAttributes As Long, _
      ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, _
      ByVal lpEnvironment As Long, ByVal lpCurrentDirectory As String, _
      lpStartupInfo As STARTUPINFO, lpProcessInformation As _
      PROCESS_INFORMATION) As Long
 
   Private Declare Function CloseHandle Lib "kernel32" _
      (ByVal hObject As Long) As Long
 
   Private Declare Function GetExitCodeProcess Lib "kernel32" _
      (ByVal hProcess As Long, lpExitCode As Long) As Long
 
   Private Const NORMAL_PRIORITY_CLASS = &H20&
   Private Const INFINITE = -1&
 
   Public Function ExecCmd(cmdline$)
      Dim proc As PROCESS_INFORMATION
      Dim start As STARTUPINFO
 
      ' Initialize the STARTUPINFO structure:
      start.cb = Len(start)
 
      ' Start the shelled application:
      ret& = CreateProcessA(vbNullString, cmdline$, 0&, 0&, 1&, _
         NORMAL_PRIORITY_CLASS, 0&, vbNullString, start, proc)
 
      ' Wait for the shelled application to finish:
         ret& = WaitForSingleObject(proc.hProcess, INFINITE)
         Call GetExitCodeProcess(proc.hProcess, ret&)
         Call CloseHandle(proc.hThread)
         Call CloseHandle(proc.hProcess)
         ExecCmd = ret&
   End Function
 
 
 
   Sub Form_Click()
      Dim retval As Long
      retval = ExecCmd("notepad.exe")
      MsgBox "Process Finished, Exit Code " & retval
   End Sub