How to do it...

Follow these steps to create a UI with two checkboxes and a button, and then apply a multi data trigger to enable/disable the button, based on the check state:

1. Let's begin by replacing the Grid with a StackPanel, having two checkbox (chkLicense and chkTerms) controls and one button:

<StackPanel HorizontalAlignment="Center"  
            VerticalAlignment="Center"> 
    <CheckBox x:Name="chkLicense"  
              Content="Yes, I accept license agreement" /> 
    <CheckBox x:Name="chkTerms"  
              Content="Yes, I accept Terms &amp; Conditions" /> 
 
    <Button HorizontalAlignment="Center"  
            Margin="0,20,0,0"  
            FontSize="20"  
            Content="Register"> 
 
    </Button> 
</StackPanel>

2. Now, modify the Button to expose its style, as follows:

<Button HorizontalAlignment="Center&quot...