{description}
{excerpt}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.
{excerpt}
{signature:C#}
 public virtual void Open(System.String fileName)
{signature}
{signature:vb.net}
Public Overridable Sub Open(ByVal fileName As String)
{signature}
{parameters}
{param:templateFileName}The complete path and file name of the template Excel file.
{param}
{exceptions}
{exception:ArgumentNullException}[Open|ExcelTemplate.Open] will throw this exception if {{null}} \(C\#\) or {{Nothing}} \(VB.NET\) is passed to the method.
{exception}
{exception:ArgumentException}
{exception}
{remarks}If your template file is the new Office Open XML \(.xlsx\) format, you can pass it into the [Open|ExcelTemplate.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|ExcelTemplate.Save], as ExcelWriter cannot convert .xlsx files to .xls. 
{remarks}
{example}{code:csharp|title=C#}

          //--- Open an Excel BIFF8 (.xls) file
          oExcelTemplate.Open(Application["templatepath"] +
               @"\DataBinding\EmployeeOrdersTemplate.xls");
   
          //--- Open an Office Open XML Excel (.xlsx) file
          oExcelTemplate.Open(Application["templatepath"] +
               @"\DataBinding\EmployeeOrdersTemplate.xlsx");
        {code}
{code:vb.net|title=vb.net}

          '--- Open an Excel BIFF8 (.xls) file
          oExcelTemplate.Open(Application("templatepath") & _
               "\DataBinding\EmployeeOrdersTemplate.xls")
       
          '--- Open an Office Open XML Excel (.xlsx) file
          oExcelTemplate.Open(Application("templatepath") & _
               "\DataBinding\EmployeeOrdersTemplate.xlsx")
        {code}

{example}