How to create list data validation for more than 255 characters in C#, VB.NET
Syncfusion Excel (XlsIO) library is a .NET Excel library used to create, read, and edit Excel documents. Also, converts Excel documents to PDF files.
The limit of ListOfValues property which is used to assign values in the List type Data Validation is only 255 characters including separators. It is not the numbers of values that is counted, but the length of characters in each value is counted.
Example: If you are assigning the ListOfValues property with new string[] { "ListItem1", "ListItem2", "ListItem3" } then the characters count is 29.
But it is possible to populate more than 255 characters into List type Data Validation through different ways. They are,
1. Creating a named range for the values and assigning that named range to FirstFormula property.
C#
IName workBookName = workbook.Names.Add("Numbers");
workBookName.RefersToRange = worksheet.UsedRange;
//Data Validation for List
IDataValidation listValidation = worksheet.Range["C3"].DataValidation;
worksheet.Range["C1"].Text = "Data Validation List in C3";
worksheet.Range["C1"].AutofitColumns();
listValidation.ListOfValues = new string[] { };
listValidation.FirstFormula = "=Numbers";
2. Directly assigning the worksheet range having values, to FirstFormula propery.
C#
//Data Validation for List
IDataValidation listValidation = worksheet.Range["C3"].DataValidation;
worksheet.Range["C1"].Text = "Data Validation List in C3";
worksheet.Range["C1"].AutofitColumns();
listValidation.ListOfValues = new string[] { };
listValidation.FirstFormula = "=A1:A600";
The following complete code snippet explains how to create a List type Data Validation for more than 255 characters through named range.
C#
using Syncfusion.XlsIO;
namespace I342696_Console
{
class Program
{
static void Main(string[] args)
{
using (ExcelEngine excelEngine = new ExcelEngine())
{
IApplication application = excelEngine.Excel;
application.DefaultVersion = ExcelVersion.Xlsx;
IWorkbook workbook = application.Workbooks.Open("../../Sample.xlsx");
IWorksheet worksheet = workbook.Worksheets[0];
IName workBookName = workbook.Names.Add("Numbers");
workBookName.RefersToRange = worksheet.UsedRange;
//Data Validation for List
IDataValidation listValidation = worksheet.Range["C3"].DataValidation;
worksheet.Range["C1"].Text = "Data Validation List in C3";
worksheet.Range["C1"].AutofitColumns();
listValidation.ListOfValues = new string[] { };
listValidation.FirstFormula = "=Numbers";
//Shows the error message
listValidation.ErrorBoxText = "Choose the value from the list";
listValidation.ErrorBoxTitle = "ERROR";
listValidation.PromptBoxText = "Data validation for list";
listValidation.IsPromptBoxVisible = true;
listValidation.ShowPromptBox = true;
workbook.SaveAs("DataValidation.xlsx");
System.Diagnostics.Process.Start("DataValidation.xlsx");
}
}
}
}
A working sample can be downloaded from ListDataValidation.zip
Take a moment to peruse the documentation, where you can find basic worksheet data manipulation options along with features like Conditional Formatting, worksheet calculations through Formulas, adding Charts in worksheet or workbook, organizing and analyzing data through Tables and Pivot Tables, appending multiple records to worksheet using Template Markers, and most importantly PDF and Image conversions etc. with code examples.
Click here to explore the rich set of Syncfusion Excel (XlsIO) library features.
Starting with v16.2.0.x, if you reference Syncfusion assemblies from trial setup or from the NuGet feed, include a license key in your projects. Refer the link to learn about generating and registering Syncfusion license key in your application to use the components without trail message.
