c# - How do I bind a datatrigger in xaml to a code-defined dependency property? -

my code behind window defines dependency property, "active"...

public partial class mainwindow : window {   public mainwindow() { initializecomponent(); }    public bool active   {      { return (bool) getvalue(activeproperty); }      set { setvalue(activeproperty, value); }   }   public static readonly dependencyproperty activeproperty =       dependencyproperty.register("active", typeof(bool), typeof(mainwindow), new uipropertymetadata(false)); } 

and bind property using 2 checkboxes in xaml. want change fill of rectangle based on property. how can make work?

<window x:class="wpftest.mainwindow"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         title="mainwindow"         height="350"         width="525"         datacontext="{binding relativesource={relativesource self}}">   <stackpanel>     <checkbox ischecked="{binding active}" />     <checkbox ischecked="{binding active}" />     <rectangle fill="gray"                width="50"                height="50">       <rectangle.style>         <style targettype="rectangle">           <style.triggers>             <datatrigger binding="{binding active}"                          value="true">               <setter property="fill"                       value="green" />             </datatrigger>           </style.triggers>         </style>       </rectangle.style>     </rectangle>   </stackpanel> </window> 

checking 1 box auto-checks other, not change rectangle color :(

locally set properties override style set properties, need remove locally set 1 , set default value in style instead:

<rectangle width="50" height="50">     <rectangle.style>         <style targettype="rectangle">             <setter property="fill" value="gray" />             <style.triggers>                 <datatrigger binding="{binding active}" value="true">                     <setter property="fill" value="green"/>                 </datatrigger>             </style.triggers>         </style>     </rectangle.style> </rectangle>