EXCEL XLSX in C#, VB.NET

		private void btnRun_Click(object sender, System.EventArgs e)
		{
			Workbook workbook = new Workbook();

			workbook.LoadFromFile(@"..\..\..\..\..\..\Data\MarkerDesignerSample.xlsx", ExcelVersion.Version2007);
			DataTable dt = (DataTable)dataGrid1.DataSource;
 
			Worksheet sheet = workbook.Worksheets[0];

			workbook.MarkerDesigner.AddParameter("Variable1", 1234.5678);
			workbook.MarkerDesigner.AddDataTable("Country", dt);
 			workbook.MarkerDesigner.Apply();

			sheet.AllocatedRange.AutoFitRows();
			sheet.AllocatedRange.AutoFitColumns(); ;
    

			workbook.SaveToFile("Sample.xlsx");
			ExcelDocViewer(workbook.FileName);
		}

		private void ExcelDocViewer( string fileName )
		{
			try
			{
				System.Diagnostics.Process.Start(fileName);
			}
			catch{}
		}

		Private Sub btnRun_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnRun.Click
			Dim workbook As New Workbook()

			workbook.LoadFromFile("..\..\..\..\..\..\Data\MarkerDesignerSample.xlsx",ExcelVersion.Version2007)
			Dim dt As DataTable = CType(dataGrid1.DataSource, DataTable)

			Dim sheet As Worksheet = workbook.Worksheets(0)

			workbook.MarkerDesigner.AddParameter("Variable1",1234.5678)
			workbook.MarkerDesigner.AddDataTable("Country",dt)
			workbook.MarkerDesigner.Apply()

			sheet.AllocatedRange.AutoFitRows()
			sheet.AllocatedRange.AutoFitColumns()


			workbook.SaveToFile("Sample.xlsx")
			ExcelDocViewer(workbook.FileName)
		End Sub

		Private Sub ExcelDocViewer(ByVal fileName As String)
			Try
				System.Diagnostics.Process.Start(fileName)
			Catch
			End Try
		End Sub