调用并导出两个gridview到两个单独的工作表中

我想将gridview1和gridview2导出到两个单独的工作表中，可以在我的代码中命名为grid view 1和grid view 2在一个Excel文件中。我有问题导出到Excel，我不知道如何调用我的导出按钮，并通过参数导出两个Gridviews:

public void ExportToExcel(Microsoft.Office.Interop.Excel._Application app, Microsoft.Office.Interop.Excel._Workbook workbook, GridView gridview, string SheetName, int sheetid)
        {
            // creating new Excelsheet in workbook
            Microsoft.Office.Interop.Excel._Worksheet worksheet = null;
            // see the excel sheet behind the program
            app.Visible = true;
            // get the reference of first sheet. By default its name is Sheet1.
            // store its reference to worksheet
            worksheet = workbook.Sheets["Sheet" + sheetid];
            worksheet = workbook.ActiveSheet;
            // changing the name of active sheet
            worksheet.Name = SheetName;
            // storing header part in Excel
            for (int i = 1; i < gridview.Columns.Count + 1; i++)
            {
                worksheet.Cells[1, i] = gridview.Columns[i - 1].HeaderText;
            }

            // storing Each row and column value to excel sheet
            for (int i = 0; i < gridview.Rows.Count - 1; i++)
            {
                for (int j = 0; j < gridview.Columns.Count; j++)
                {
                    worksheet.Cells[i + 2, j + 1] = gridview.Rows[i].Cells[j].Text.ToString();
                }
            }

            // save the application
            workbook.SaveAs(@"C:'Users'testacc'Desktop'Test'output.xls", Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlExclusive, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
            // Exit from the application
            app.Quit();
        }

我把下面的代码放在哪里?

// creating Excel Application
 Microsoft.Office.Interop.Excel._Application app  = new Microsoft.Office.Interop.Excel.Application();
// creating new WorkBook within Excel application
Microsoft.Office.Interop.Excel._Workbook workbook =  app.Workbooks.Add(Type.Missing);