C# Windows Forms RichTextBox Examples

Let us look at a simple C# Windows Forms RichTextBox example.

Example 1: RichTextBox

This example will comprise the following files:

  • RichTextBox.cs

Step 1: Create Project

  1. The first step is to create a C# Project.
  2. Go to FILE-->New-->Project to create a new project.

Step 2: Write Code

Write Code as follows:

*(a). RichTextBox.cs

Create a file named RichTextBox.cs

Here is the full code

using System;
using System.Windows.Forms;

public static class RichTextBoxExtensions {
  public static void AppendText(this System.Windows.Forms.RichTextBox box, string text, System.Drawing.Color color) {
    box.SelectionStart = box.TextLength;
    box.SelectionLength = 0;

    box.SelectionColor = color;
    box.SelectionColor = box.ForeColor;

namespace Examples {
  class MainForm : Form {
    public static void Main() {
      Application.Run(new MainForm());

    public MainForm() {
      Text = "RichTextBox example";

      richTextBox.Parent = this;
      richTextBox.Dock = DockStyle.Fill;

      richTextBox.AppendText("Colored text :n");
      richTextBox.SelectionStart = richTextBox.TextLength;
      richTextBox.SelectionColor = System.Drawing.Color.Red;
      richTextBox.AppendText("  Redn");
      richTextBox.SelectionColor = System.Drawing.Color.Green;
      richTextBox.AppendText("  Greenn");
      richTextBox.SelectionColor = System.Drawing.Color.Blue;
      richTextBox.AppendText("  Bluen");
      richTextBox.SelectionColor = richTextBox.ForeColor;

    private RichTextBox richTextBox = new RichTextBox();


Simply copy the source code into your C# Project,Build and Run. Alternatively download the code using the links provided below, then open the .csproj project, build and run.


Download the code using the below links:

Number Link
1. Download Example
2. Follow code author

Related Posts