Change the color of a line in Richtextbox

Question

I want the second line, change to another color.

My code is as follows :

 private void WindowLoaded(object sender, RoutedEventArgs e)
    {
        UpdateRTBOnDifferentThread("stackoverflow.com" + Environment.NewLine+"stackoverflow.org" + Environment.NewLine);
    }

    private void UpdateRTBOnDifferentThread(string message)
    {
        Dispatcher.Invoke(DispatcherPriority.Normal, new DispatcherOperationCallback(delegate
        {
            var newExternalParagraph = new Paragraph(new Run(message)) {Foreground = Brushes.Black};
            richTextBox1.Document.Blocks.Add(newExternalParagraph);
            return null;
        }), null);
    } 

The second line is: "stackoverflow.org"

I want to change the color after the enter text

Answer 1

You can either use String.Split to break the lines inside your UpdateRTBOnDifferentThread method, or you can have this method accept an array of strings. Then you can iterate the array and add N Paragraph objects or N Run objects inside the same paragraph, and control the foreground of each string separately.