Question

I need to use a RichTextBox, not a normal textbox because of the way it keeps the caret position, from line to line. But I need to keep the text in the same font all the time even if it is pasted.

At the moment I have it selecting the entire text and changing the font to the original (Lucida Console) but it look horrible when you paste into it as it flashes blue.

Answer 1

If you are handling the pasting programatically don’t use the Paste method. Instead use Clipboard.GetDataObject().GetData(DataFormats.Text) to get the text in a string and then add the text using the Rtf or Text property to the RichTextBox:

string s = (string)Clipboard.GetDataObject().GetData(DataFormats.Text);
richTextBox.Text += s;

Otherwise you could handle the Ctrl+V key press:

void RichTextBox1_KeyDown(object sender, KeyEventArgs e)
{
    if(e.Control == true && e.KeyCode == Keys.V)
    {
        string s = (string)Clipboard.GetDataObject().GetData(DataFormats.Text);
        richTextBox.Text += s;
        e.Handled = true; // disable Ctrl+V
    }
}