How do I open a DLL file in Excel?
|
Open topic with navigation Show
Instant Protection PLUS 3 DLL Microsoft Excel SampleThis is a guide which shows you the steps taken to create the Microsoft Excel example for the Instant Protection PLUS 3 DLL. This sample was created in Microsoft Excel 2013. The instructions would be similar for older versions of Microsoft Excel. Microsoft Office applications (such as Word, Excel, Access, etc...) may run in a ClickToRun environment. This environment has known limitations that make it problematic for licensed Office add-ins and macros to use global locations. Consequently, licensed add-ins and macros that target these environments should only use user-specific locations for licenses and aliases. See this knowledge-base article for more details. Step 1 - Creating a new ProjectOpen Microsoft Excel and select Blank workbook from the available templates. To save your workbook as a macro-enabled workbook, click File, Save As, and Browse. Enter a file name and change the “Save as type” to Excel Macro-Enabled Workbook (*.xlsm) or Excel Macro-Enabled Template (*.xltm), depending on your project type. Step 2 - Creating a Splash Screen worksheetTo create a splash screen displaying a message, rename your worksheet to “Splash” by double-clicking on “Sheet1” near the bottom-left of your application window. Add additional worksheets by clicking the + to the right of your worksheet’s name or by pressing Shift+F11. Edit the “Splash” worksheet to display a message to users if their license has not been validated. Step 3 - Importing the Visual Basic ModuleOpen the VBA editor (Alt+F11). Right-click VBAProject from the Project Explorer and choose ‘Import File…’. Browse to the ..//Instant Plus//Samples folder select the IP2Lib32_Definitions.bas module and click ‘Open’.
Step 4 - Creating your macro's source codeIn the Integration Assistant, click the drop-down list and select VBA-Excel as your programming language.
 Click the "..." to browse for the newly created Instant Protection PLUS 3 (*.ipp file). Click Generate to render the source code for the Workbook_Open macro you will need to copy into your workbook.
Step 5 - IntegrateReturn to your Excel project’s VBA project explorer. Double-click ThisWorkbook in your VBAProject. Paste the source code generated in the Integration Assistant. If necessary merge in with any previous macros. Save your changes and close the VBA Editor. Close the unprotected workbook. You should see all worksheets disappear and only the "Splash" screen should be visible. Click Yes to save your changes. Step 6 - ProtectStep 7 - Test and DeployOpen Excel, go to File, Open, browse to your workbook and open. Enable Macros if prompted. Your Workbook_Open Macro calls the Instant Protection PLUS 3 DLL to check the license. The application must be properly deployed in order to function correctly on a 'clean' machine that has not previously had Instant Protection PLUS 3 installed. The Instant Protection PLUS 3 DLL library files must be installed to the system directory along with any custom splash screen or product logo images. It is recommended to use a helper executable to initialize the license files to avoid permissions issues on Windows Vista and later. These requirements are described in detail in the Deployment topic. Modular ProgrammingAs you recall from our computer programming lessons, one of the key concepts in good software design is modularity: breaking our code into functional subroutines or functions, each responsible for a specific task with a clear interface for calling it. Once encapsulated in a self-contained function, this functionality can be re-used in many locations in your program. This improves the size, quality, maintainability and readability of your program. Also, without modular design, your program can only grow so much before you lose your arms and legs. I’d go as much to say that a good modular design is one of the first signs I look for in judging the quality of a programmer. Using Functions Outside of ExcelExpanding on the modularity concept, why limit ourselves to functions we coded in our VBA application? There are many functions out there already developed by others and proven robust and performant – why not break the boundaries of Excel VBA and consume them, or CALL them from our Excel VBA program? Some of the things we would like to do can’t even be achieved without using an external function that is not part of Excel VBA or that we can write ourselves without consuming such a function. Consider, for example, the need to control the Window properties (maybe size or position) of another application running on our Windows operating system, from Excel VBA. This Window is governed by the operating system and we have no access to it without calling a Windows function that has access to that Window and can manipulate it. What is a DLL?A DLL (Dynamic Link Library) is a package of functions/subroutines callable by other programs running in the Windows operating system. Typically, a DLL file has the .dll extension, although other extensions are possible for certain types of files (e.g. .ocx for ActiveX controls). Most of the Windows operating system functionality itself is implemented by DLLs, each calling and called by other programs. One such example would be the Comdlg32.DLL file, offering a function to open the File Open dialog box for selecting file(s) – a functionality needed by many programs running on Windows. Almost every program that is installed on a Windows machine registers its own DLLs in the Windows registry. Once a DLL is properly registered with Windows, its published functions can be consumed and called by any other program running on that machine, and that includes Excel VBA, of course! Almost every program developed for running on Windows makes use of existing DLL files and contributes its own DLL files to the party. For an elaborate discussion on DLLs, read this Microsoft article. Calling a DLL from Excel VBAIn order to gain access to the functions/subroutines included in a DLL file, you need to first declare your intentions to do that, using the Declare statement. If you intent to call the PlayMusic sub exposed by the (imaginary) FunActivities.DLL file, your declaration statement may look like this:
If the PlayMusic sub expects arguments, the declaration must also include those arguments (passed ByRef by default):
As with any declaration in VBA, you can precede the declaration with the Public or Private qualifiers to contol for the scope of the sub in your VBA project:
Declaring a function is very similar, with the notable return type expected as with any function:
Sometimes, a function name as exposed by the DLL may be in conflict with VBA or other variables used in your program. To circumvent this, you can specify a local name to reference that function by in your VBA program, instead of the original name as determined by the DLL developer. In this case, you will add the Alias qualifier to reference the original function name, while the declared name will be your own local flavor:
Another way of referencing a function in the DLL, instead of by its published (or exported) name, would be by its index, or ordinal number, as defined by the developer. In this case, we must use the Alias qualifier and the “#” character to indicate an ordinal number:
Referencing by ordinal number guaranties consistency even if the function name will be changed in future versions, but developers are very aware not to mess with function names in DLLs, and this way is rarely used nowadays. For a complete and detailed explanation of the Declare statement, read this Microsoft article. Calling a DLL Sub from Excel VBA ExampleThe following example is implemented in The Ultimate Excel Date Picker. If you got this neat perk already, you may be familiar with the following code, as the Date Picker comes with its VBA code open. In developing The Ultimate Excel Date Picker, I needed to reference several DLL services, one of which is to simulate a keyboard TAB pressed. I could have used the SendKeys() VBA function, but let me tell you – it has more promise than it delivers. I would not rely on this statement at all in any of my programs. However, the Windows user32.DLL file offers a keyboard event sub, directly from Windows, not VBA. Here’s the declaration part I have:
And here’s the function implementing a TAB keypress. Two calls are invoked here, one for pressing the TAB key, another for releasing it:
The two Constants used are declared as usual at the top of the module:
I know I know, you must be thinking: what’s that PtrSafe qualifier I did not talk about, and what’s the story with the “IF VBA7 clause and LongPtr… All about that in next week’s Blog post! How can I open DLL files?Open the folder with the DLL file. Once you find the folder, hold the Shift key and right-click the folder to open the command prompt directly in that folder. Type "regsvr32 [DLL name]. dll" and press Enter.
How do I decode a DLL file?Go to File and click Open and choose the dll that you want to decompile, After you have opend it, it will appear in the tree view, Go to Tools and click Generate Files(Crtl+Shift+G), select the output directory and select appropriate settings as your wish, Click generate files.
How do I fix error loading DLL in Excel 2016?You may encounter an Access Database 'error in loading DLL' because of some problem with Microsoft Data Access Components (MDAC) or a damaged DLL file. You can resolve the error manually by registering for Dao360 and Msado15 DDL files, updating MDAC, reinstalling the Access program, or cleaning registry errors.
What is DLL in VBA?DLLs (dynamic-link libraries) are portable libraries that can be created by one application and used by another. In particular one can create a DLL in C then have its functions run from Excel by calling them from VBA.
|
