wpf - How do I use a ViewModel variable for a DynamicResource? -

this isn't mahapps.metro-specific, happens i'm using. have set of viewmodels have string property representing icon use resource xaml file.

public class commandviewmodel : viewmodel {     public commandviewmodel(string displayname, icommand command, string icon)     {         if (command == null)             throw new argumentnullexception("command");          displayname = displayname;         command = command;         icon = icon;     }      public icommand command { get; private set; }     public string icon { get; set; } } 

icon end being "appbar_add" mahapps.metro.resources. these defined in icons.xaml file.

how write in itemtemplate such correct resource shows. i'm either getting errors on execution (not @ edit/build) or i'm getting no icons @ all.

the "no icon" xaml looks this:

<itemscontrol itemssource="{binding}">     <itemscontrol.itemtemplate>         <datatemplate>             <stackpanel orientation="horizontal">                 <rectangle width="20" height="20">                     <rectangle.fill>                         <visualbrush visual="{dynamicresource {binding path=icon}}" />                     </rectangle.fill>                 </rectangle>                 <textblock margin="15,6">                                                 <hyperlink command="{binding path=command}">                         <textblock text="{binding path=displayname}" />                     </hyperlink>                 </textblock>             </stackpanel>         </datatemplate>     </itemscontrol.itemtemplate> </itemscontrol> 

my attempts caused errors using staticresource, think fundamentally incorrect.

how should referencing icon property name of resource want?

edit

more code requested, here's example of does work:

<rectangle width="20" height="20">     <rectangle.fill>         <visualbrush visual="{staticresource appbar_add}" />     </rectangle.fill> </rectangle> 

what need let "appbar_add" value property on viewmodel -- icon property above.

the resources in resourcedictionary in separate file (icon.xaml) , following:

<canvas x:key="appbar_add" width="76" height="76" clip="f1 m 0,0l 76,0l 76,76l 0,76l 0,0">     <path width="38" height="38" canvas.left="19" canvas.top="19" stretch="fill" fill="{dynamicresource blackbrush}" data="f1 m 35,19l 41,19l 41,35l 57,35l 57,41l 41,41l 41,57l 35,57l 35,41l 19,41l 19,35l 35,35l 35,19 z "/> </canvas> 

you can use converter work. refer below code. have 2 style make + symbol in red color or black color in icon.xaml.

<resourcedictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"> <canvas x:key="appbar_add_black" width="76" height="76" clip="f1 m 0,0l 76,0l 76,76l 0,76l 0,0">     <path width="38" height="38" canvas.left="19" canvas.top="19" stretch="fill" fill="black" data="f1 m 35,19l 41,19l 41,35l 57,35l 57,41l 41,41l 41,57l 35,57l 35,41l 19,41l 19,35l 35,35l 35,19 z "/> </canvas> <canvas x:key="appbar_add_red" width="76" height="76" clip="f1 m 0,0l 76,0l 76,76l 0,76l 0,0">     <path width="38" height="38" canvas.left="19" canvas.top="19" stretch="fill" fill="red" data="f1 m 35,19l 41,19l 41,35l 57,35l 57,41l 41,41l 41,57l 35,57l 35,41l 19,41l 19,35l 35,35l 35,19 z "/> </canvas> 

refer view code. viewmodel

 public partial class mainwindow : window     {         public mainwindow()         {             initializecomponent();             this.datacontext = new commandviewmodel("red");         }     }  public class commandviewmodel :inotifypropertychanged {     public event propertychangedeventhandler propertychanged;     private void onpropertychanged(string propname)     {         if (propertychanged != null)         {             propertychanged(this, new propertychangedeventargs(propname));         }     }     public commandviewmodel(string icon)     {          icon = icon;     }      private string icon;      public string icon     {         { return icon; }         set { icon = value; }     }  }  class iconconverter : ivalueconverter {     public object convert(object value, type targettype, object parameter, system.globalization.cultureinfo culture)     {         string str = (string)value;         resourcedictionary myresourcedictionary = new resourcedictionary();         myresourcedictionary.source =                 new uri("icon.xaml",                         urikind.relative);         if (str.equals("black"))         {                           return myresourcedictionary["appbar_add_black"];         }         else         {             return myresourcedictionary["appbar_add_red"];         }     }      public object convertback(object value, type targettype, object parameter, system.globalization.cultureinfo culture)     {         throw new notimplementedexception();     } }