<Grid>

        <Button x:Name="btnTest" Width="120" Height="36" Content="Code In XAML" Click="btnTest_Click"/>

        <x:Code>

            <![CDATA[

                private void btnTest_Click(object sender,RoutedEventArgs e)

                {

                    this.Close();

                }

            ]]>

        </x:Code>

    </Grid>