Changing font for richtextbox without losing formatting

Question

How to change the font of all the contents of a richtextbox without losing formatting?

I am trying to use

rtb.SelectAll();
rtb.SelectionFont = new F         


        

Answer 1

You can pass the new font name while keeping other values intact by using the existing richtextbox font properties. For changing only font name of a selected text, you need to do:

if (rtb.SelectionFont !=null)
    rtb.SelectionFont = new Font(fontName, rtb.SelectionFont.Size, rtb.SelectionFont.Style);

Note that above code will only work, if all the selected text has same formatting (font size, style etc). This is detected by checking the SelectionFont property first, it will be null if the selection contains a mix of styles.

Now to change the font name of all the contents of richtextbox while keeping other formatting intact, you need to loop through all the characters of the richtextbox and apply font name one by one.

for (int i = 0; i < rtb.TextLength; i++)
{
    rtb.Select(i, 1);
    rtb.SelectionFont = new Font(fontName, rtb.SelectionFont.Size, rtb.SelectionFont.Style);
}