MAKEMSI quickly and reliably creates MSI files in a non-programmatic way\Tips and TricksUser Interface TipsBrowse for File Dialog (in DLL Custom Action)

---

Browse for File Dialog (in DLL Custom Action)

This uses the "guts" of a DLL custom action by "Kallely L Sajan" (from InstallSite, see "File Browse Dialog" by Jeff Briggs) and the "TryMeDllCustomAction.MM" sample to create a "browse for file" dialog in an msi.

The following code was extracted from Kallely's "BrowseForFile.cpp":

    //***********************************************************
    //** Call back function for EnumChildWindows()
    //**---------------------------------------------------------
    //** Author:    Kallely L Sajan
    //***********************************************************
    BOOL CALLBACK EnumChildProc(HWND hwnd,LPARAM lParam)
    {
      TCHAR buf[100];
      GetClassName( hwnd, (LPTSTR)&buf, 100 );

      if ( _tcscmp ( buf, (_T("RichEdit20W")) ) == 0 )
      {
       *(HWND*)lParam = hwnd;
       return FALSE;
      }
    }

    UINT __stdcall BrowseForFile(MSIHANDLE hInstall)
    {
        //MessageBox(NULL, "BrowseForFile", "BrowseForFile", MB_OK);

        //Set up storage for PATHTOFILE
        TCHAR szOriginalPath[MAX_PATH];
        DWORD cchValue = sizeof(szOriginalPath)/sizeof(TCHAR);
        ZeroMemory(szOriginalPath, sizeof(TCHAR)*MAX_PATH);

        // Get PATHTOFILE
        MsiGetProperty(hInstall, TEXT("PATHTOFILE"), szOriginalPath, &cchValue);

        long    lErrMsg = 0;
        OPENFILENAME ofn;

        ZeroMemory(&ofn, sizeof(ofn));

        TCHAR szFilters[] =
        _T("All Files (*.*)\0*.*\0")
        _T("Text File (*.txt)\0*.txt\0");

        // Initialize OPENFILENAME structure.
        ofn.lStructSize = sizeof(ofn);
        ofn.hwndOwner = GetForegroundWindow();
        ofn.lpstrFile = szOriginalPath;
        ofn.nMaxFile = sizeof(szOriginalPath);
        ofn.lpstrFilter = szFilters;
        ofn.nFilterIndex = 1;
        ofn.lpstrFileTitle = NULL;
        ofn.nMaxFileTitle = 0;
        ofn.lpstrInitialDir = NULL;
        //ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
        //ofn.Flags = OFN_HIDEREADONLY;

        if (GetOpenFileName(&ofn))
        {
            MsiSetProperty(hInstall, TEXT("PATHTOFILE"), szOriginalPath);

            //This next bit of code fixes a problem that occurs if the author is
            //using an Edit box for the path. For whatever reason, if a user
            //types into the edit box before browsing for a file or folder
            //the Edit box is not updated once the custom action completes.
            //Much of the following code was modified from
            //Kallely L Sajan's IsLicensedViewed article from InstallSite.org
            HWND hWnd;
            HWND hWndChild=NULL;

            hWnd = FindWindow(NULL, "Default - InstallShield Wizard");
            if (hWnd) {
                EnumChildWindows( hWnd, EnumChildProc, (LPARAM)&hWndChild );
                if ( hWndChild ) {
                    TCHAR buf[100];
                    _tcscpy(buf, szOriginalPath);
                    //the following call will not work if _UNICODE is defined in Prepocessor definitions
                    SendMessage(hWndChild, WM_SETTEXT, 0, (LPARAM)szOriginalPath);
                }
            }
        }
        return ERROR_SUCCESS;
    }

Insert the above code and the stub below just before the "<$/DllCa-C>" command in "TryMeDllCustomAction.MM":

    //============================================================================
    <$DllCaEntry "Browse4File">
    //============================================================================
    {
        //--- Call Kallely's code ---
        CaDebug(PROGRESS_LOG, "Invoking Kallely's BrowseForFile()");
           UINT BrowseRc;
           BrowseRc = BrowseForFile(hInstall);
        CaDebug(PROGRESS_LOG, "Completed Kallely's BrowseForFile()");
        return( BrowseRc );
    }
    <$/DllCaEntry>

Then we need to schedule the invokation etc by inserting the following immediately after the "<$/DllCa-C>" command in "TryMeDllCustomAction.MM":

;--- Set starting directory and file mask ---
<$PropertyCa "PATHTOFILE" Value="[TempFolder]*.*"                    Seq="CostFinalize-" SeqTable=^InstallUISequence^>

;--- Invoke the DLL ---------------------------------------------------------
<$DllCa Binary="MyTestDll.dll"  Entry=^<$DllCaEntry? "Browse4File">^ Seq="CostFinalize-" SeqTable=^InstallUISequence^ Type="Immediate" Condition="<$DLLCA_CONDITION_INSTALL_ONLY>">

;--- Make a copy (you may wish to use more than once) ---
<$PropertyCa "RETURNED_FILE" Value="[PATHTOFILE]"                    Seq="CostFinalize-" SeqTable=^InstallUISequence^>

;--- Display the returned value (also abort - don't really want to install...) ---
#(
    <$AbortIf
        Condition="<$DLLCA_CONDITION_INSTALL_ONLY>"
          Message=^The DLL returned "[RETURNED_FILE]". Aborting the install now...^
         SeqTable="InstallUISequence"
              Seq="CostFinalize-"
    >
#)

You can then build and test the msi, a verbose log will give you more details.

Improvements

I left Kallely's code exactly as was purely to demonstrate how you can easily grab code and insert it into a dll based custom action.

Some recommended improvements:

• My sample doesn't handle silent installs well (where you'd want to pass the value on the command line).

• Also what happens if the user cancels the browse etc?

• You would want to add error handling, for example if the path doesn't exist it will "return" the value you supplied! It should clear it so you can test for this.

• I'd add logging of input and output.

• The return code is currently meaningless.

• You can also remove or alter the "InstallShield" stuff.

Please email me any feedback, additional information or corrections. See this page online (look for updates) MAKEMSI© is (C)opyright Dennis Bareis 2003-2008 (All rights reserved). Saturday May 28 2022 at 3:11pm Visit MAKEMSI's Home Page