C＃中的部分只读文本框

Question

I've got a list of illegal positions and characters that can't move from those positions. How would I prevent those from being modified in the TextChanged event? Every solution I've come up with has been extremely hacky and unreliable, or has relied on the KeyDown event, which doesn't prevent the user from deleting the read-only text in other ways (select the text and delete it, or just press the backspace key).

I've thought of doing something like this:

//CharPos is a class with an int (CharPos.Position) and a char that 
//should be at that int's position (CharPos.Ch)
foreach (CharPos p in IllegalPositions)
{
    console.Text = console.Text.Remove(p.Position, 1);
    console.Text = console.Text.Insert(p.Position, p.Ch.ToString());
}

But it completely messes up and goes on an infinite loop. And even if I stopped it from doing that, it wouldn't work if you changed the character count of the text, by using the delete key for example. Maybe I could use regex somehow? (I dunno, I have no experience at all with regex).

Answer 1

Can you combine multiple TextBoxes (for editable parts) with TextBlocks (for readonly parts)? You would just need to play with styling of the two to match

Answer 2

Could you please check the link below:

Disabling or making it readonly a part of the values in a Text Box (.net)

rtBox.Select(0, (rtBox.Text = "I am fixed content").Length);
rtBox.SelectionProtected = true;
rtBox.AppendText(Environment.NewLine);