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 Using ShellEx from Visual Basic - Start any document from its filename only


 NOTE: this code has been superceded by the version at the new site.



 

Download the ShellEx project files (29kb)

The ShellExecute API function is a much better way of starting applications that VB's own Shell. It allows you to specify file names or internet resources as the file to shell, and will automatically find the associated executable and start it for you. Essentially its the same function as called by the Start->Run box.

[Shell Test Application Picture]



The source below provides a simple wrapper function for use of ShellExecute called ShellEx. The sample code in the download also includes a simple Browse For Folder implementation and uses some of the code from the Common Dialog/Direct project to implement a File Open dialog through API code.

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" _
  (ByVal hWnd As Long, ByVal lpOperation As String, _
  ByVal lpFile As String, ByVal lpParameters As String, _
  ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long

Private Declare Function ShellExecuteForExplore Lib "shell32.dll" Alias "ShellExecuteA" _
  (ByVal hWnd As Long, ByVal lpOperation As String, _   ByVal lpFile As String, lpParameters As Any, _
  lpDirectory As Any, ByVal nShowCmd As Long) As Long

Public Enum EShellShowConstants
    essSW_HIDE = 0
    essSW_MAXIMIZE = 3
    essSW_MINIMIZE = 6
    essSW_SHOWMAXIMIZED = 3
    essSW_SHOWMINIMIZED = 2
    essSW_SHOWNORMAL = 1
    essSW_SHOWNOACTIVATE = 4
    essSW_SHOWNA = 8
    essSW_SHOWMINNOACTIVE = 7
    essSW_SHOWDEFAULT = 10
    essSW_RESTORE = 9
    essSW_SHOW = 5
End Enum

Private Const ERROR_FILE_NOT_FOUND = 2&
Private Const ERROR_PATH_NOT_FOUND = 3&
Private Const ERROR_BAD_FORMAT = 11&
Private Const SE_ERR_ACCESSDENIED = 5        ' access denied
Private Const SE_ERR_ASSOCINCOMPLETE = 27
Private Const SE_ERR_DDEBUSY = 30
Private Const SE_ERR_DDEFAIL = 29
Private Const SE_ERR_DDETIMEOUT = 28
Private Const SE_ERR_DLLNOTFOUND = 32
Private Const SE_ERR_FNF = 2                ' file not found
Private Const SE_ERR_NOASSOC = 31
Private Const SE_ERR_PNF = 3                ' path not found
Private Const SE_ERR_OOM = 8                ' out of memory
Private Const SE_ERR_SHARE = 26


Public Function ShellEx( _
        ByVal sFIle As String, _
        Optional ByVal eShowCmd As EShellShowConstants = essSW_SHOWDEFAULT, _
        Optional ByVal sParameters As String = "", _
        Optional ByVal sDefaultDir As String = "", _
        Optional sOperation As String = "open", _
        Optional Owner As Long = 0 _
    ) As Boolean
Dim lR As Long
Dim lErr As Long, sErr As Long
    If (InStr(UCase$(sFIle), ".EXE") <> 0) Then
        eShowCmd = 0
    End If
    On Error Resume Next
    If (sParameters = "") And (sDefaultDir = "") Then
        lR = ShellExecuteForExplore(Owner, sOperation, sFIle, 0, 0, essSW_SHOWNORMAL)
    Else
        lR = ShellExecute(Owner, sOperation, sFIle, sParameters, sDefaultDir, eShowCmd)
    End If
    If (lR < 0) Or (lR > 32) Then
        ShellEx = True
    Else
        ' raise an appropriate error:
        lErr = vbObjectError + 1048 + lR
        Select Case lR
        Case 0
            lErr = 7: sErr = "Out of memory"
        Case ERROR_FILE_NOT_FOUND
            lErr = 53: sErr = "File not found"
        Case ERROR_PATH_NOT_FOUND
            lErr = 76: sErr = "Path not found"
        Case ERROR_BAD_FORMAT
            sErr = "The executable file is invalid or corrupt"
        Case SE_ERR_ACCESSDENIED
            lErr = 75: sErr = "Path/file access error"
        Case SE_ERR_ASSOCINCOMPLETE
            sErr = "This file type does not have a valid file association."
        Case SE_ERR_DDEBUSY
            lErr = 285: sErr = "The file could not be opened because the target application is busy. Please try again in a moment."
        Case SE_ERR_DDEFAIL
            lErr = 285: sErr = "The file could not be opened because the DDE transaction failed. Please try again in a moment."
        Case SE_ERR_DDETIMEOUT
            lErr = 286: sErr = "The file could not be opened due to time out. Please try again in a moment."
        Case SE_ERR_DLLNOTFOUND
            lErr = 48: sErr = "The specified dynamic-link library was not found."
        Case SE_ERR_FNF
            lErr = 53: sErr = "File not found"
        Case SE_ERR_NOASSOC
            sErr = "No application is associated with this file type."
        Case SE_ERR_OOM
            lErr = 7: sErr = "Out of memory"
        Case SE_ERR_PNF
            lErr = 76: sErr = "Path not found"
        Case SE_ERR_SHARE
            lErr = 75: sErr = "A sharing violation occurred."
        Case Else
            sErr = "An error occurred occurred whilst trying to open or print the selected file."
        End Select
               
        Err.Raise lErr, , App.EXEName & ".GShell", sErr
        ShellEx = False
    End If

End Function


Here are a few samples of using the ShellEx function:

To open a the user's browser at a particular internet site
    ShellEx "http://www.dogma.demon.co.uk", , , , , Me.hWnd

To print a document
    ShellEx "C:\My Documents\Music\Brown Paper Bag.doc", , , , "print", Me.hWnd

To explore from a folder
    ShellEx "C:\My Documents\Music", , , , "explore", Me.hWnd

Start VB, minimised, load a project and run it
    ShellEx _
       "C:\Program Files\DevStudio\Vb\vb5.exe",_
        essSW_SHOWMINNOACTIVE, _
        "/run C:\Stevemac\VB\Develop\BmpTile\gBmpTile.vbg", _
       ,Me.hWnd



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Copyright © 1998-1999, Steve McMahon ( steve@vbaccelerator.com). All Rights Reserved.
Last updated: 15 August 1999