Recently I encountered a situation where I was to highlight a word in WPF RichTextBox. So I thought, I should share a small tip to show how to highlight a word (by setting background color) in a WPF Rich TextBox. Here is the code:
/// <summary>
/// This method highlights a word with a given color in a WPF RichTextBox
/// </summary>
/// <param name="richTextBox">RichTextBox Control</param>
/// <param name="word">The word which you need to highlighted</param>
/// <param name="color">The color with which you highlight</param>
private void HighlightWordInRichTextBox(RichTextBox richTextBox, String word, SolidColorBrush color)
{
//Current word at the pointer
TextRange tr = new TextRange(richTextBox.Document.ContentEnd, richTextBox1.Document.ContentEnd);
tr.Text = word;
tr.ApplyPropertyValue(TextElement.BackgroundProperty, color);
}