I have a requirement- need to display RTF content in context menu. I
am able to host a rich textbox in a contextmenu strip using
ToolStripControlHost class. But assigning some RTF content to the
containing rich textbox control does not display in actual RTF
format- it just dislpays as plain  text. Here's the code am using:

//Custom richtextbox to handle bg color in readonly mode
public class MyRichTextBox : RichTextBox
   {
       public MyRichTextBox()
       {
       }

       public new bool ReadOnly
       {
           get
           {
               return base.ReadOnly;
           }
           set
           {
               if (value == true)
               {
                   this.BackColor = Color.White;
               }

               base.ReadOnly = value;
           }
       }

   }

----------------------------------------------------------------
public Form1()
       {
           InitializeComponent();

           m_cmenu.Items.Add(new ToolStripMenuItem("Edit"));
           m_cmenu.Items.Add(new ToolStripSeparator());

           MyRichTextBox m_richTextBox = new MyRichTextBox();
           m_richTextBox.BorderStyle =
System.Windows.Forms.BorderStyle.None;
           m_richTextBox.Dock = System.Windows.Forms.DockStyle.Fill;
           m_richTextBox.ReadOnly = true;
           m_richTextBox.ScrollBars =
System.Windows.Forms.RichTextBoxScrollBars.None;

           ToolHost textItem = new ToolHost(m_richTextBox);
           //Assign sample RTF content.
           m_richTextBox.Rtf = @"{\rtf1\fbidis\ansi
\ansicpg1252\deff0\deflang1033{\fonttbl{\f0\fswiss\fprq2\fcharset0
Arial;}{\f1\fnil\fcharset0 Microsoft Sans Serif;}}
\viewkind4\uc1\pard\ltrpar\sa200\sl276\slmult1\f0\fs28 This is\fs22
\i some\i0  \ul Rich\ulnone  \b text\b0\par
\pard\ltrpar\f1\fs17\par }";

           m_cmenu.Items.Add(textItem);
           this.ContextMenuStrip = m_cmenu;//Assign contextmenu for
Form

       }