当所有列表项的总和小于 256 时

你可以从任何配置文件中读取所有项目，也可以内联键入它。

考虑它是否保存在配置文件中

// Read all list items from config file
string[] countryDV = ConfigurationManager.AppSettings["countryDV"].Split(',').Select(s => s.Trim().ToUpper()).ToArray();
int DVRowLimit = (Int16.MaxValue); 
CellRangeAddressList countryDVAddList = new CellRangeAddressList(1, DVRowLimit, 0, 0);
dvConstraint = (XSSFDataValidationConstraint)validationHelper.CreateExplicitListConstraint(countryDV);
// In case of Inline list values 
// use this approach:  dvConstraint = (XSSFDataValidationConstraint)validationHelper.CreateExplicitListConstraint(new string[] { "USA", "CANADA"});
dataValidation = (XSSFDataValidation)validationHelper.CreateValidation(dvConstraint, countryDVAddList);
dataValidation.ShowErrorBox = true;
dataValidation.SuppressDropDownArrow = true;
dataValidation.ErrorStyle = 0;
dataValidation.CreateErrorBox("InvalidValue", "Select Valid country.");
dataValidation.ShowErrorBox = true;
dataValidation.CreatePromptBox("country Data Validation", "Enter country.");
dataValidation.ShowPromptBox = true;
sheet.AddValidationData(dataValidation);