User Input Validation

//Add a List validation to B column. Values should be in a list
var val = worksheet.DataValidations.AddListValidation("B:B");
//Shows error message when the input doesn't match the accepted values
val.ShowErrorMessage = true;
//Style of warning. "information" and "warning" allow users to ignore the validation,
//while "stop" and "undefined" doesn't
val.ErrorStyle = OfficeOpenXml.DataValidation.ExcelDataValidationWarningStyle.information;
//Title of the error mesage box
val.ErrorTitle = "This is the title";
//Message of the error
val.Error = "This is the message";
//Set to true to show a prompt when user clics on the cell
val.ShowInputMessage = true;
//Set the message for the prompt
val.Prompt = "This is a input message";
//Set the title for the prompt
val.PromptTitle = "This is the title from the input message";
//Define the accepted values
val.Formula.Values.Add("This is accepted");
val.Formula.Values.Add("This is also accepted");
val.Formula.Values.Add("Any other thing is rejected");
//Set to true if blank value is accepted
val.AllowBlank = false;

//Add a List validation to the C column
var val2 = worksheet.DataValidations.AddListValidation("C:C");
//Define the Cells with the accepted values
val2.Formula.ExcelFormula = "=$D$3:$D$5";
//Fill the cells with the accepted values
worksheet.Cells["D3"].Value = "Val1";
worksheet.Cells["D4"].Value = "Val2";
worksheet.Cells["D5"].Value = "Val3";

//Add a List validation to the C column
var val3 = worksheet.DataValidations.AddIntegerValidation("E:E");
//For Integer Validation, you have to set error message to true
val3.ShowErrorMessage = true;
val3.Error = "The value must be an integer between 0 and 10";
//Minimum allowed Value
val3.Formula.Value = 0;
//Maximum allowed Value
val3.Formula2.Value = 10;
//If the cells are not filled, allow blanks or fill with a valid value, 
//otherwise it could generate a error when saving 
val3.AllowBlank = true;

//Add a DateTime Validation to column F
var val4 = worksheet.DataValidations.AddDateTimeValidation("F:F");
//For DateTime Validation, you have to set error message to true
val4.ShowErrorMessage = true;
//Minimum allowed date
val4.Formula.Value = new DateTime(2017,03,15, 01, 0,0);
//Maximum allowed date
val4.Formula2.Value= new DateTime(2017, 03, 16, 12, 0, 0);
val4.AllowBlank = true;

//Add a TextLength Validation to column G
var val5 = worksheet.DataValidations.AddTextLengthValidation("G:G");
//For TextLenght Validation, you have to set error message to true
val5.ShowErrorMessage = true;
//Minimum allowed text lenght
val5.Formula.Value = 3;
//Maximum allowed text lenght
val5.Formula2.Value = 5;
val5.AllowBlank = true;