VBA Shell and Wait with Exit Code

Question

I am wrapping up an office application (VBA) that makes a call to a C# console application to perform some of the heavy lifting for the application (large simulation program). I would like to be able to have the VBA application wait for the console application to complete as well as retreive the exit code from the console application. I have been able to do the former, but have yet to be able to retrieve the exit code from the application. Is there any way that I can use something like

Diagnostics.Process.Start(filePath)

I have seen this in VB but not sure about VBA. Otherwise, any other suggestions?

Answer 1

This functionality has been wrapped up in the ShellAndWait function.

Excellent write up on it here.

Answer 2

Have a look at WaitForSingleObject and GetExitCodeProcess functions.

Example Usage:

Private Declare Function GetExitCodeProcess Lib "kernel32" (ByVal hProcess As Long, lpExitCode As Long) As Long
Private Declare Function WaitForSingleObject Lib "kernel32" (ByVal hHandle As Long, ByVal dwMilliseconds As Long) As Long
Private Declare Function OpenProcess Lib "kernel32" (ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, ByVal dwProcessId As Long) As Long
Private Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
Private Declare Function FormatMessage Lib "kernel32" Alias "FormatMessageA" (ByVal dwFlags As Long, lpSource As Any, ByVal dwMessageId As Long, ByVal dwLanguageId As Long, ByVal lpBuffer As String, ByVal nSize As Long, Arguments As Long) As Long

Public Const INFINITE = &HFFFF
Public Const PROCESS_ALL_ACCESS = &H1F0FFF

Sub RunApplication(ByVal Cmd as String)

    lTaskID = Shell(Cmd, vbNormalFocus)
    ' Get process handle
    lPID = OpenProcess(PROCESS_ALL_ACCESS, True, lTaskID)
    If lPID Then
        ' Wait for process to finish
        Call WaitForSingleObject(lPID, INFINITE)
        ' Get Exit Process
        If GetExitCodeProcess(lPID, lExitCode) Then
            ' Received value
            MsgBox "Successfully returned " & lExitCode, vbInformation
        Else
            MsgBox "Failed: " & DLLErrorText(Err.LastDllError), vbCritical
        End If
    Else
        MsgBox "Failed: " & DLLErrorText(Err.LastDllError), vbCritical
    End If
    lTaskID = CloseHandle(lPID)
End Sub

Public Function DLLErrorText(ByVal lLastDLLError As Long) As String
    Dim sBuff As String * 256
    Dim lCount As Long
    Const FORMAT_MESSAGE_ALLOCATE_BUFFER = &H100, FORMAT_MESSAGE_ARGUMENT_ARRAY = &H2000
    Const FORMAT_MESSAGE_FROM_HMODULE = &H800, FORMAT_MESSAGE_FROM_STRING = &H400
    Const FORMAT_MESSAGE_FROM_SYSTEM = &H1000, FORMAT_MESSAGE_IGNORE_INSERTS = &H200
    Const FORMAT_MESSAGE_MAX_WIDTH_MASK = &HFF

    lCount = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM Or FORMAT_MESSAGE_IGNORE_INSERTS, 0, lLastDLLError, 0&, sBuff, Len(sBuff), ByVal 0)
    If lCount Then
        DLLErrorText = Left$(sBuff, lCount - 2) ' Remove line feeds
    End If

End Function