How to identify a password protected excel document and provide the password dynamically?

         
 private void btnCreate_Click(object sender, System.EventArgs e)
 {
     ExcelEngine excelEngine = new ExcelEngine();
 
                IApplication application = excelEngine.Excel;
 
                application.OnPasswordRequired += application_OnPasswordRequired;
 
               IWorkbook workbook;
 
                string inputPath = GetFullTemplatePath("Sample.xlsx");
 
                workbook = application.Workbooks.Open(inputPath, ExcelOpenType.Automatic);                     
 
                IWorksheet sheet = workbook.Worksheets[0];
 
                workbook.Version = ExcelVersion.Excel2010;
                string fileName = @"../../Output/Output.xlsx";
 
                workbook.SaveAs(fileName);
 }
 
         void application_OnPasswordRequired(object sender, PasswordRequiredEventArgs e)
         {
                e.NewPassword = "syncfusion";
         }
 

            Dim excelEngine As ExcelEngine = New ExcelEngine()
 
            Dim application As IApplication = excelEngine.Excel
 
            application.OnPasswordRequired += application_OnPasswordRequired
 
            Dim workbook As IWorkbook
 
            Dim inputPath As String = GetFullTemplatePath("Sample.xlsx")
 
            workbook = application.Workbooks.Open(inputPath, ExcelOpenType.Automatic)
 
            Dim sheet As IWorksheet = workbook.Worksheets(0)
 
            workbook.Version = ExcelVersion.Excel2010
            Dim fileName As String = "../../Output/Output.xlsx"
 
            workbook.SaveAs(fileName)
 
        Private Sub application_OnPasswordRequired(ByVal sender As Object, ByVal e As PasswordRequiredEventArgs)
            e.NewPassword = "syncfusion"
        End Sub