How can I hide the caret of a RichTextBox control?

Please don't refer me to this:

https://www.experts-exchange.com/questions/20597134/Hiding-the-Caret-in-a-RichTextBox-Control.html#8412211

Because it doesn't work.

I am using VS 2005.

Do you want to hide the caret and still be able to edit, or do you just want to prevent the RichTextBox control from getting focus?

Bob

Hello Bob,

It's a read-only RichTextBox BUT the user should be able to select text and right-click on it to show it's contextMenu.

try to subclass the richeditctrl and do hidecaret whenever you receive paint event

or something like this
            protected override void WndProc(ref Message m)
            {
                  base.WndProc (ref m);
                        HideCaret( this.Handle.ToInt32() );
            }

Hello Agarici,

Your code worked after I add the following to my exsiting class:

        [DllImport("user32.dll", EntryPoint="HideCaret")]
        public static extern long HideCaret(IntPtr hwnd);

          protected override void WndProc(ref Message m)
          {
               base.WndProc (ref m);
                    HideCaret( RichTextBox.Handle );
          }

But there's a problem. When the user clicks on the RichTextBox control the caret appears then disappear. And if I hold the mouse button down I see the caret flashing as long as I'm holding the mouse button down :(

How can I solve that?

Also, I'm getting the following error message when I'm closing the form:

ObjectDisposeException was unhandled

Cannot access a disposed object.
Object name: 'RichTextBox'.

Thanks a lot.

Try this custom RichTextBox class:

using System;
using System.Windows.Forms;
using System.ComponentModel;
using System.Runtime.InteropServices;

public class ReadOnlyRichTextBox : System.Windows.Forms.RichTextBox
{

  [DllImport("user32.dll")]
  private static extern int HideCaret (IntPtr hwnd);

  ReadOnlyRichTextBox()
  {
    this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.ReadOnlyRichTextBox_Mouse);
    this.MouseUp += new System.Windows.Forms.MouseEventHandler(this.ReadOnlyRichTextBox_Mouse);
    base.ReadOnly = true;
    base.TabStop = false;
    HideCaret(this.Handle);
  }


  protected override void OnGotFocus(EventArgs e)
  {
    HideCaret(this.Handle);
  }

  protected override void OnEnter(EventArgs e)
  {
    HideCaret(this.Handle);
  }

  [DefaultValue(true)]
  public new bool ReadOnly
  {
    get { return true; }
    set { }
  }

  [DefaultValue(false)]
  public new bool TabStop
  {
    get { return false; }
    set { }
  }

  private void ReadOnlyRichTextBox_Mouse(object sender, System.Windows.Forms.MouseEventArgs e)
  {
    HideCaret(this.Handle);
  }
}

Bob

After creating a new class and pasting your code and then...

        private void Form1_Load(object sender, EventArgs e)
        {
            ReadOnlyRichTextBox cxz = new ReadOnlyRichTextBox();
            //this.Controls.Add(cxz);
        }

I got:

Error      1      'ReadOnlyRichTextBox.ReadOnlyRichTextBox()' is inaccessible due to its protection level

What's wrong?

Ok I added 'public' before ReadOnlyRichTextBox() constructor and it worked very good.

But the cursor is appearing when the form is resized.

i think the problem is you have added the winproc to the form class
i was suggesting you derive a new class from richtextbox and add the winproc to it.
also this is the reason you get the exception.

try something like:

public class ReadOnlyRichTextBox : System.Windows.Forms.RichTextBox
{

  [DllImport("user32.dll")]
  private static extern int HideCaret (IntPtr hwnd);

  ReadOnlyRichTextBox()
  {
   }

         protected override void WndProc(ref Message m)
          {
               base.WndProc (ref m);
                    HideCaret( this.Handle.ToInt32() );
          }
}

in my test program this seems to be working as expected

hth,
A.