c# - Change default bitmap in CheckBox -

i find solution setter.targetname not work against element basedon setting. not understand how prement him me. have class:

public class mycheckbox: checkbox {   public bool defaultvalue   {     { return (bool)getvalue(defaultvalueproperty); }     set { setvalue(defaultvalueproperty, value); }   }   public static readonly dependencyproperty defaultvalueproperty =       dependencyproperty.register("defaultvalue", typeof(bool), typeof(mycheckbox), new uipropertymetadata(false));     protected override void ontoggle()   {     this.ischecked = this.ischecked == null ? !defaultvalue : this.ischecked.value ? false : true;   } } 

and xaml

<style targettype="{x:type checkbox}">   <style.resources>     <imaging:bitmapimage x:key="checkboxstatussource" urisource="falseifnull.png"/> <!-- icon if [ischecked] [null] -->   </style.resources>   <setter property="template">     <setter.value>       <controltemplate targettype="{x:type checkbox}">         <image x:name="checkboxstatus" source="{dynamicresource checkboxstatussource}"/>         <controltemplate.triggers>           <trigger property="ischecked" value="true">             <setter targetname="checkboxstatus" property="source" value="b.png"/><!-- icon if [ischecked] [true] -->           </trigger>           <trigger property="ischecked" value="false">             <setter targetname="checkboxstatus" property="source" value="c.png"/><!-- icon if [ischecked] [false] -->           </trigger>         </controltemplate.triggers>       </controltemplate>     </setter.value>   </setter> </style>  <style targettype="{x:type my:mycheckbox}" basedon="{staticresource {x:type checkbox}}">   <style.triggers>     <trigger property="defaultvalue" value="true">       <!-- !!!!!!!!!!!!!!this need change [urisource] in [checkboxstatussource] "trueifnull.png"!!!!!!!!!!!!!! -->     </trigger>   </style.triggers> </style> 

perhaps there solution

unless need extend checkbox other reasons, you're trying here can done attached properties too, , allow have 1 single style checkboxes.

public static class checkboxextensions {     public static void setdefaultvalue(checkbox element, bool value)     {         element.setvalue(defaultvalueproperty, value);     }     public static bool getdefaultvalue(checkbox element)     {         return (bool)element.getvalue(defaultvalueproperty);     }     // using dependencyproperty backing store defaultvalue.  enables animation, styling, binding, etc...     public static readonly dependencyproperty defaultvalueproperty =         dependencyproperty.registerattached("defaultvalue", typeof(bool), typeof(checkboxextensions), new uipropertymetadata(false)); } 

this property available use in checkbox in solution, , in style , template use checkboxes. in case...

<style targettype="{x:type checkbox}">   <style.resources>     <imaging:bitmapimage x:key="checkboxstatussourcefalse" urisource="falseifnull.png"/> <!-- icon if [ischecked] [null] , [defaultvalue] [false] -->     <imaging:bitmapimage x:key="checkboxstatussourcetrue" urisource="trueifnull.png"/> <!-- icon if [ischecked] [null] , [defaultvalue] [true] -->   </style.resources>   <setter property="template">     <setter.value>       <controltemplate targettype="{x:type checkbox}">         <image x:name="checkboxstatus" source="{dynamicresource checkboxstatussourcefalse}"/>         <controltemplate.triggers>           <multitrigger>             <multitrigger.conditions>               <condition property="local:checkboxextensions.defaultvalue" value="true" />               <condition property="ischecked" value="{x:null}" />             </multitrigger.conditions>             <setter targetname="checkboxstatus" property="source" value="{dynamicresource checkboxstatussourcefalse}"/>           </multitrigger>           <trigger property="ischecked" value="true">             <setter targetname="checkboxstatus" property="source" value="b.png"/><!-- icon if [ischecked] [true] -->           </trigger>           <trigger property="ischecked" value="false">             <setter targetname="checkboxstatus" property="source" value="c.png"/><!-- icon if [ischecked] [false] -->           </trigger>         </controltemplate.triggers>       </controltemplate>     </setter.value>   </setter> </style> 

edit: if still need extend checkbox, style work both regular checkbox , mycheckbox implementation. create style that's based on one.

<style targettype="{x:type my:mycheckbox}" basedon="{staticresource {x:type checkbox}}">     ... </style> 

and if want access defaultvalue property code-behind, can way:

checkboxextensions.setdefaultvalue(checkbox, true); bool defaultvalue = checkboxextensions.getdefaultvalue(checkbox);