Extended WPF Toolkit - Binding Text of richtextbox <p>I am newbie in WPF. I need make TwoWay and OneWayToSource bind to string variable. I want use richtextbox from Extended WPF Toolkit ,because I think it is the easy way. </p> <p>So I try use richtebox from this library in xaml, code is here:</p> <pre><code>&lt;Window x:Class="PokecMessanger.ChatWindow" xmlns:extToolkit="clr-namespace:Microsoft.Windows.Controls;assembly=WPFToolkit.Extended" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="ChatWindow" Height="429" Width="924"&gt; ///... &lt;extToolkit:RichTextBox Name="rtbRpText" Text="{Binding _rpText, Mode=OneWayToSource}" Grid.Column="0"&gt;&lt;/extToolkit:RichTextBox&gt; </code></pre> <p>In code behind, I have this code:</p> <pre><code> private string _rpText = string.Empty; public ChatWindow(PokecCommands pokecCmd) { rtbRpText.DataContext = _rpText; } </code></pre> <p>Problem is, if I wrote something in richtextbox, variable _rpText is still empty, where can be problem?</p>