change color of row in richtextbox by changing tabindex in c# with wpf

Question

I'm converting the project I've done with winform before to wpf. But I have some problems.

I paint the lines I want of the text in the richtextbox.

winform code in below,

private void TextBoxGcode_TabIndexChanged(object sender, EventArgs e)  
    {  
        if (0 < GcodeSayi)  
        {  
            TextBoxGcode.Find(lines[GcodeSayi - 1], RichTextBoxFinds.MatchCase);  
            TextBoxGcode.SelectionBackColor = Color.White;  
            TextBoxGcode.Find(lines[GcodeSayi], RichTextBoxFinds.MatchCase);  
            TextBoxGcode.SelectionBackColor = Color.DodgerBlue;  
        }  
        else  
        {  
            TextBoxGcode.SelectAll();  
            TextBoxGcode.SelectionBackColor = Color.White;  
  
        }  
  
    }  

TextBoxGcode.TabIndex = TempGcodeSayi;

it could be like this. Changing the color of the relevant line in the richtextbox with the line number I entered from a textbox. I need only line

How can I do it with WPF? Please help.

Thanks,

Answer 1

painting the selected row will fix this.