How to set rich text format in cells in C#.NET

EasyXLS Excel library can be used to export Excel files in C#. The library works with .NET Framework or .NET Core platform.

Step 1: Download EasyXLS Excel Library for .NET

To download the trial version of EasyXLS Excel Library, press the below button:

Download EasyXLS™ Excel Library for C#

If you already own a license key, you may login and download EasyXLS from your account.

Install the downloaded EasyXLS installer for v8.6 or earlier.

Step 2: License file setup

Step required for EasyXLS v9.0 or later.

If you are using a trial, generate a trial license file from EasyXLS trials page. The trial license is valid for 30-days.

If you own a license key, you may login to the account that purchased the license and generate the license file from:

Setup the license file into your project using these guidelines.

Step 3: Create a C# project

If don't have a project, create one as ASP.NET web application, windows forms app, console application, class library or service.

Step 4: Include EasyXLS library into project

EasyXLS.dll must be added as reference to your project. EasyXLS.dll can be found:
- Inside the downloaded archive at Step 1 for EasyXLS v9.0 or later
- Under installation path for EasyXLS v8.6 or earlier, in "Dot NET version" folder.

Add EasyXLS reference

Step 5: Run C# code that sets rich text format in Excel cells

Execute the following C# code that exports rich text format (RTF) in an Excel cell.

/* ---------------------------------------------------------------
 * Tutorial 19
 * This tutorial shows how to create an Excel file in C# having
 * multiple sheets. The first sheet is filled with data and the
 * first cell of the second row contains data in rich text format.
 * --------------------------------------------------------------- */

using System;
using EasyXLS;
using EasyXLS.Constants;

public class Tutorial19
    static void Main()
        Console.WriteLine("Tutorial 19\n----------\n");

        // Create an instance of the class that exports Excel files having two sheets
        ExcelDocument workbook = new ExcelDocument(2);
        // Set the sheet names
        workbook.easy_getSheetAt(0).setSheetName("First tab");
        workbook.easy_getSheetAt(1).setSheetName("Second tab");

        // Get the table of data for the first worksheet
        ExcelTable xlsFirstTable = ((ExcelWorksheet)workbook.easy_getSheetAt(0)).easy_getExcelTable();

        // Create the string used to set the RTF in cell
        String sFormattedValue = "This is <b>bold</b>.";
        sFormattedValue += "\nThis is <i>italic</i>.";
        sFormattedValue += "\nThis is <u>underline</u>.";
        sFormattedValue += "\nThis is <underline double>double underline</underline double>.";
        sFormattedValue += "\nThis is <font color=red>red</font>.";
        sFormattedValue += "\nThis is <font color=rgb(255,0,0)>red</font> too.";
        sFormattedValue += "\nThis is <font face=\"Arial Black\">Arial Black</font>.";
        sFormattedValue += "\nThis is <font size=15pt>size 15</font>.";
        sFormattedValue += "\nThis is <s>strikethrough</s>.";
        sFormattedValue += "\nThis is <sup>superscript</sup>.";
        sFormattedValue += "\nThis is <sub>subscript</sub>.";
        sFormattedValue += "\n<b>This</b> <i>is</i> <font color=red face=\"Arial Black\" size=15pt>" + 
                                 "<underline double>formatted</underline double></font> <s>text</s>.";

        // Set the rich text value in cell 
        xlsFirstTable.easy_getCell(1, 0).setHTMLValue(sFormattedValue); 
        xlsFirstTable.easy_getCell(1, 0).setDataType(DataType.STRING);
        xlsFirstTable.easy_getCell(1, 0).setWrap(true); 

        // Export Excel file
        Console.WriteLine("Writing file C:\\Samples\\Tutorial19 - RTF for Excel cells.xlsx.");
        workbook.easy_WriteXLSXFile("C:\\Samples\\Tutorial19 - RTF for Excel cells.xlsx");

        // Confirm export of Excel file
        String sError = workbook.easy_getError();
        if (sError.Equals(""))
            Console.Write("\nFile successfully created. Press Enter to Exit...");
            Console.Write("\nError encountered: " + sError + "\nPress Enter to Exit...");

        // Dispose memory


EasyXLS Excel libraries:

Excel Library for C#
full .NET version to import, export or convert Excel files
Excel Writer for C#
.NET version to create and export Excel files
Download EasyXLS™ Excel Library for C#

File formats:

MS Excel 97 - 2003
MS Excel 2007 - 2019
MS Excel 2021
Office 365