WPF Extensibility Hacks or WEX - Includes EventTrigger, ReactiveTrigger, InvokeMethodAction, InvokeCommandAction etc.

<UserControl x:Class="Wex.Lib.Demo.Views.Demos.PropertyTrigger" 
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
           xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
           xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"      
           xmlns:wex="clr-namespace:Wex.Lib.Interactions;assembly=Wex.Lib"      
           mc:Ignorable="d"
           d:DesignWidth="640" d:DesignHeight="480">
    <Grid x:Name="LayoutRoot">
        <i:Interaction.Triggers>
            <!--
            <wex:PropertyTrigger ElementName="txtData" Property="Text">
                <wex:InvokeCommandAction CommandName="UpdateDataCommand">
                    <wex:InvokeCommandAction.Conditions>
                    <wex:InvokingConditions>
                        <wex:InvokingCondition Value="Hello"/>
                        <wex:InvokingCondition ElementName="myCheckBox" Property="IsChecked" Value="True"/>
                    </wex:InvokingConditions>
                  </wex:InvokeCommandAction.Conditions>
                </wex:InvokeCommandAction>
            </wex:PropertyTrigger>
            -->
        </i:Interaction.Triggers>
        <StackPanel>
            <TextBlock FontSize="20" Text="Property Trigger Demo"/>
            <TextBlock Margin="4" TextWrapping="Wrap" 
                       Text="This demo shows how to invoke an action when a property is changed, based on multiple conditions. Type 'Hello' in the below text box, with the check box checked, to fire the command"/>
            <TextBox Margin="4" Name="txtData" Text="Type Hello here, with the checkbox checked"/>
            <StackPanel Background="LightGray" Margin="5">
                <TextBlock Margin="4" Text="{Binding Data}" FontSize="14"/>
                <CheckBox Name="myCheckBox" Content="Check to Fire The Command if 'Hello' is entered"/>
            </StackPanel>
        </StackPanel>
    </Grid>
</UserControl>