Create excel xll file

The sample project below demonstrates how you create an XLL add-in providing a sample user-defined function allocated to a custom function category.

You can download the source code of the project as well as plenty more examples on the How-To pages: VB. Excel user-defined functions UDFs are used to build custom functions in Excel for the end user to use them in formulas. This definition underlines the main restriction of an UDF: it should return a result that can be used in a formula - not an object of any given type but a number, a string, or an error value Booleans and dates are essentially numbers.

When used in an array formula, the UDF should return a properly dimensioned array of values of the types above. Excel shows the value returned by the function in the cell where the user calls the function. In other words, a UDF cannot be registered for all users on the machine. Instead, it must be registered for every user separately.

Make sure that you have administrative permissions before running Visual Studio. Run Visual Studio via the Run as Administrator command.

In the first wizard window, you choose your programming language and specify the oldest Excel version your add-in needs to support:. If you don't know anything about strong names or don't have a special strong name key file, choose Generate new.

If you are in doubt, choose Generate new. If, later on, you need to use a specific strong name key file, you will be able to specify its name on the Signing tab of your project properties; you are required to unregister your add-in project before using another strong name.

The solution contains an only project, the Excel XLL add-in project. The project contains the XLLModule. The XLLModule. To review the code, in Solution Explorer, right-click the file and choose View Code in the context menu.

An UDF must return a string, double or integer. Please see the next step for the use of this class. This property was added by the COM add-in project wizard. You use it as an entry point to the Excel object model if this is required in your add-in. This property returns the current instance of the XLL module, a very useful thing when, for example, you need to access a method defined in the module from the code of another class.

In addition, it demonstrates how to return an error such as NUM! To integrate your XLL addin in Microsoft Excel, you should supply Excel with a user-friendly add-in name, function names, parameter names, help topics, etc. Specify the add-in name in the Properties window. You use the toolbar provided by the in-place designer to select, move, add or remove components.

In this XLL add-in, you specify properties of the Excel Function Category component as demonstrated in the screenshot above and add a new function descriptor to the category component as shown below:.

In the function descriptor, you set the FunctionName property, which provides a combo box that allows choosing a function from the list of functions defined in the XLLContainer class; select the function you created on Step 3.

Other properties are:. In the same way, you describe the arguments of the function: add a parameter descriptor and select a parameter in the ParameterName property see below.

When renaming functions and arguments, you have to reflect these changes in appropriate descriptors. In the opposite case, Excel will not receive the information required. In the Project Options window, specify the full path to excel. The table below provides links to step-by-step instructions for deploying XLL addins. Find background information in Deploying Office extensions. You may want to check the following sections under Add-in Express tips and notes :.

Solid framework for deep customization of Microsoft Office. Use solution templates, visual designers and components to develop version-neutral, secure and easy deployable extensions for all Office versions.

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Let me know how you think it can be improved. You can find the add-in, help file, and spreadsheet in HelloXll. It should pop you into Excel with the add-in loaded. Once you run the macro XLL. DOC, you can access the help file from the function wizard via 'Help on this function.

This can make a big difference if you are using large arrays of doubles. Category "My Category". Documentation "Additional remarks go here. JP Ronse. You can use this function to display a custom dialog box that tells the user that the add-in has been activated, to read from or write to the registry, or to check licensing information. This function is not called when an Excel session closes, normally or abnormally, with the add-in installed. You can use this function to display a custom dialog box that tells the user that the add-in has been deactivated, or to read from or write to the registry.

If Excel passes an argument equal to 1, this function should return a string typically, the name of the add-in ; otherwise, it should return VALUE! The xlAutoRegister function allows the XLL to search its internal lists of exported functions and commands to register the function with the argument and return the specified types. This enables the XLL to return dynamically allocated arrays, strings, and external references to the worksheet without memory leaks.

For more information, see Memory Management in Excel. This simplifies thread-safe design in your XLL. For more information, see Multithreaded Recalculation in Excel. Excel and user-defined functions can run on bit operating systems to take advantage of performance benefits over bit operating systems. Be careful when you convert between values in the XLOPER12 structure and native types like int or pointers to preserve the values in the larger type.

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