wpf - setting dependency property in user control style -

i implemented user control dependency property looks this:

public partial class myuc : usercontrol, inotifypropertychanged {     public static readonly dependencyproperty mybackgroundproperty =         dependencyproperty.register("mybackground", typeof(brush), typeof(myuc),              new frameworkpropertymetadata(brushes.white,                  frameworkpropertymetadataoptions.affectsrender));      public brush mybackground     {         { return (brush)getvalue(mybackgroundproperty); }         set { setvalue(mybackgroundproperty, value); }     }      //... } 

and try set property in xaml follows:

<usercontrol x:class="custom.myuc"          x:name="myucname"          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"          xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"           xmlns:d="http://schemas.microsoft.com/expression/blend/2008"           xmlns:local="clr-namespace:custom"          mc:ignorable="d"          tabindex="0" keyboardnavigation.tabnavigation="local"           horizontalcontentalignment="left" verticalcontentalignment="top"           mouseleftbuttondown="onmouseleftbuttondown">      <usercontrol.style>         <style targettype="local:myuc">                   <setter property="mybackground" value="black"/>         </style>     </usercontrol.style>         <border borderthickness="0">         //...     </border> </usercontrol> 

it compiles when run app following exception:

set property 'system.windows.setter.property' threw exception.' line number '..' , line position '..'."

how can solve this?

the problem arises because you're trying apply style targettype="myuc" element of type usercontrol.

the solution apply style outside of control. example when use control in window:

<window.resources>     <style targettype="local:myuc">         <setter property="mybackground" value="red" />     </style> </window.resources> <grid>     <local:myuc /> </grid> 

as test added code user control:

public partial class myuc {     public myuc()     {         initializecomponent();     }         public static readonly dependencyproperty mybackgroundproperty =         dependencyproperty.register("mybackground", typeof(brush), typeof(myuc),          new propertymetadata(brushes.white, propertychangedcallback));      private static void propertychangedcallback(dependencyobject dependencyobject,          dependencypropertychangedeventargs dependencypropertychangedeventargs)     {         ((myuc)dependencyobject).mybackgroundpropertychanged(             (brush)dependencypropertychangedeventargs.newvalue);     }      private void mybackgroundpropertychanged(brush newvalue)     {         background = newvalue;     }      public brush mybackground     {         { return (brush)getvalue(mybackgroundproperty); }         set { setvalue(mybackgroundproperty, value); }     } } 

which results in control having red background.