Rich textbox color for new input (WPF, C#)

Question

0.00/5 (No votes)

See more:

I want to change my rich textbox color for new input. The textbox loads a text at startup. I want to control that new user input is still highlighted for example red color or yellow background. The new text can be added anywhere and not only at the end. If it would be only at the end I could easily add a red letter there.

The problem behind is that the user should edit a text and the changes should be highlighted.

My code :
C# program

C#

string RTF = @"{\rtf1\ansi\deff0 " +
@"{\colortbl;\red0\green0\blue0;\red255\green0\blue0;} "+
@"line1 \line "+
@"\cf2 "+
@"line 2 \line "+
@"\cf1 "+
@"line 3 "+
@"}";

MemoryStream stream = new MemoryStream(ASCIIEncoding.Default.GetBytes(RTF));
TextRange range = new TextRange(demo.Document.ContentStart, demo.Document.ContentEnd);
range.Load(stream, DataFormats.Rtf);

XAML Code

C#

<RichTextBox HorizontalAlignment="Left" Height="116" Margin="37,266,0,0" Grid.Row="1" x:Name="demo" VerticalAlignment="Top" Width="381">
         
        </RichTextBox>

What I have tried:

I have already added the RichTextBoxFormatBar from Extended WPF Toolkit. It allows the user to format the content but I did not found a solution for setting the default color for new input.

Posted 22-Jul-16 21:54pm

Andre Dieme

Updated 26-Jul-16 0:39am

Add a Solution

Comments

[no name] 23-Jul-16 11:23am

Maybe a start, not a nice one more a hack I think. And a lot of things need to be fixed:


private void RichTextBox_TextChanged(object sender, TextChangedEventArgs e)
{
    rtb.Selection.ApplyPropertyValue(TextElement.ForegroundProperty, Brushes.Red);
}

Andre Dieme 23-Jul-16 12:35pm

Thanks a lot! It works great.
I changed the code a bit because this methode could be applied to all Richt textboxes.

private void RichTextBox_TextChanged(object sender, TextChangedEventArgs e)
{
RichTextBox x = (RichTextBox)sender;
x.Selection.ApplyPropertyValue(TextElement.ForegroundProperty, Brushes.Red);
}

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Bhola Ram Sahu · Answer 1 · 2016-07-26T00:39:00

You can compare both the given text and the new input text.

If any mismatch found, then format it.

string oldText = "whatever";
string newText = rtbGivenText.Text;

for (int i = 0; i < oldText.Length; i++)
{
if (oldText[i]==newText[i])
{
rtbGivenText.Select(i, i+1);
rtbGivenText.SelectionColor = Color.Red;
}
}