UseDLL Example

InstallShield 2018 » InstallScript Language Reference

Note • To call this function in a Basic MSI setup, you must first create a custom action for the entry-point function, execute the custom action in a sequence or as the result of a dialog's control event, and then build the release.

/*--------------------------------------------------------------*\

*

* InstallShield Example Script

*

* Demonstrates the UseDLL and the UnUseDLL functions.

*

* UseDLL is called to load an example .dll file into memory. A

* function in this .dll file is then called to demonstrate how

* .dll functions can be used in an installation. Finally,

* UnUseDLL is called to unload the example .dll file from memory.

*

* Note: This script requires that the constant DLL_FILE be set

*       to the fully qualified name of a .dll file that contains

*       a function called TheExportedFunction. The format of that

*       function must match the prototype declaration below.

*

\*--------------------------------------------------------------*/

// Include Ifx.h for built-in InstallScript function prototypes.

#include "Ifx.h"

#define DLL_FILE SUPPORTDIR ^ "TheDLL.dll"

// Prototype TheExportedFunction in TheDLL.dll.

prototype TheDLL.TheExportedFunction (INT, WPOINTER);

export prototype ExFn_UseDLL(HWND);

function ExFn_UseDLL(hMSI)

    STRING   svString;

    INT      nValue;

    WPOINTER psvString;

    NUMBER   nResult;

    BOOL     bDone;

begin

    // Load the .dll file into memory.

    nResult = UseDLL (DLL_FILE);

    if (nResult = 0) then

        MessageBox ("UseDLL successful \n\n.dll file loaded.", INFORMATION);

    else

        MessageBox ("UseDLL failed.\n\nCouldn't load .dll file.", INFORMATION);

        abort;

    endif;

    // bDone controls the following while loop.

    bDone = FALSE;

    // Loop while bDone is FALSE.

    while (bDone = FALSE)

        // Disable the Back button in installation dialogs.

        Disable (BACKBUTTON);

        // Get a string from the user.

        AskText ("Enter an example string.", "Example string.", svString);

        // Get a pointer to the string to pass to TheExportedFunction.

        psvString = &svString;

        // Get the string length to pass to TheExportedFunction.

        nValue = StrLength (svString);

        // Call TheExportedFunction.

        TheExportedFunction (nValue, psvString);

        // Display the string to observe how it was altered by TheExportedFunction.

        SprintfBox (INFORMATION, "UseDLL", "TheExportedFunction() changed the string " +

                   "to: %s", svString);

        // Give the user a chance to do another example.

        if (AskYesNo ("Do another example?", YES) = NO) then

            bDone = TRUE;

        endif;

    endwhile;

    // Remove the .dll file from memory.

    if (UnUseDLL (DLL_FILE) < 0) then

        MessageBox ("UnUseDLL failed.\n\n.dll file still in memory.", SEVERE);

    else

        MessageBox ("UnUseDLL successful.\n\n.dll file removed from memory.",

                   INFORMATION);

    endif;

end;

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