The XLL Plus library contains a variety of C++ classes for use in writing Excel add-ins. All of these classes have been designed to simplify the use of Excel programming objects, but only a few are needed by programmers building the standard run of add-in functions.
It is possible to make productive use of the library with a simple understanding of just two classes: CXlOper and COper.
The table below summarises the principal C++ object classes available in the library.
| Class | Description |
|---|---|
| COper | An argument sent by Excel to an add-in function. |
| CXlOper | A result sent back to Excel by an add-in function. |
| CXllApp | The object representing the add-in library itself. It can be used to store data that is global to the library. |
| imtx<T> | A two-dimensional array of numbers, booleans or strings. |
| CXlArray | An array of floating-point numbers passed by or returned to Excel. |
| CXlMenu | A run-time menu added to Excel's main application menu bar. |
| CXlToolbar | A run-time toolbar added to Excel's main window. |
| CXlDialog | A dialog displayed using Excel's native dialog mechanism. |
| CXllFinder | A tool for finding and replacing the contents of cells. |
| CXllCom | Offers an interface for calling Excel's COM automation interface. |
| CXllPushApp | Base class for multi-threaded add-ins which automatically update formula cells. |
| CXlFuncs | A class containing static methods for calling Excel worksheet functions. |
| CXlMacros | A class containing static methods for calling Excel macro functions. |
| CXlOperCache | A class which caches the results of add-in functions, preventing unnecessary recalculations. |
| CXllFn | A representation of a single add-in function. |
| CExcelWnd | An MFC window class that provides access to the Excel application window. |
| CXlRef | A reference to a rectangular block of cells. |
| CXlHandleStore<T, S> | A store of objects, which can be accessed from add-in functions by their numeric "handle". |
| CXlFormulaRefresh | A utility class, which can be used to force recalculation of any cell whose formula contains a specified function. |