Returns the WorkbookFormat based on the file extension of the specified file.
Parameters
- fileName
- The filename of an excel file.
Return Value
The workbook format based on the file extension of the file, or null if the correct format cannot be determined.
Target Platforms: Android 4.4+, iOS 8+
Development Environments: Visual Studio 2015+, Visual Studio for Mac Preview, Xamarin for Visual Studio 4.2+
