Gets the default extension for this Workbook object.
Assemblies: Microsoft.Office.Tools.Excel (in Microsoft.Office.Tools.Excel.dll)
Microsoft.Office.Tools.Excel.v4.0.Utilities (in Microsoft.Office.Tools.Excel.v4.0.Utilities.dll)
The default extension is an IWorkbookExtension object that is implemented by the Visual Studio Tools for Office runtime.
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.