Opens an ExcelWriter template spreadsheet. A template is a file created in Microsoft Excel that contains data markers where data source values will be inserted.
templateFileNameThe complete path and file name of the template Excel file.
ArgumentNullExceptionOpen will throw this exception if
Nothing(VB.NET) is passed to the method.
RemarksIf your template file is the new Office Open XML (.xlsx) format, you can pass it into the Open method just as you would a BIFF8 (.xls) Excel file. You will need to remember to give the output file a ".xlsx" extension when you call Save, as ExcelWriter cannot convert .xlsx files to .xls.