下拉框的:
Microsoft.Office.Interop.Excel.Application application = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel.Workbook workbook = application.Workbooks.Open(@"C:\Book1.xlsx", Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing);
Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1];
string strValue = ((Microsoft.Office.Interop.Excel.Range)worksheet.Cells[1, 1]).Validation.Formula1;
1,1是下拉框行列坐标。下拉项以,号分隔。