c# - How do I read an Image's Height and Width from my View Model? -

i want line-drawing operations viewmodel (i.e. add collection of lines bound itemscontrol on view).

for need know height , width of image in view. how them ?

there workarounds mentioned in other posts they wpf , none of them work on metro.

public static class sizeobserver {     public static readonly dependencyproperty observeproperty = dependencyproperty.registerattached(         "observe",         typeof(bool),         typeof(sizeobserver), new propertymetadata(null, onobservechanged));     //new frameworkpropertymetadata(onobservechanged));      public static readonly dependencyproperty observedwidthproperty = dependencyproperty.registerattached(         "observedwidth",         typeof(double),         typeof(sizeobserver), null);      public static readonly dependencyproperty observedheightproperty = dependencyproperty.registerattached(         "observedheight",         typeof(double),         typeof(sizeobserver), null);         public static bool getobserve(frameworkelement frameworkelement)     {         //frameworkelement.assertnotnull("frameworkelement");         return (bool)frameworkelement.getvalue(observeproperty);     }      public static void setobserve(frameworkelement frameworkelement, bool observe)     {         //frameworkelement.assertnotnull("frameworkelement");         frameworkelement.setvalue(observeproperty, observe);     }      public static double getobservedwidth(frameworkelement frameworkelement)     {         //frameworkelement.assertnotnull("frameworkelement");         return (double)frameworkelement.getvalue(observedwidthproperty);     }      public static void setobservedwidth(frameworkelement frameworkelement, double observedwidth)     {         //frameworkelement.assertnotnull("frameworkelement");         frameworkelement.setvalue(observedwidthproperty, observedwidth);     }      public static double getobservedheight(frameworkelement frameworkelement)     {         //frameworkelement.assertnotnull("frameworkelement");         return (double)frameworkelement.getvalue(observedheightproperty);     }      public static void setobservedheight(frameworkelement frameworkelement, double observedheight)     {         //frameworkelement.assertnotnull("frameworkelement");         frameworkelement.setvalue(observedheightproperty, observedheight);     }      private static void onobservechanged(dependencyobject dependencyobject, dependencypropertychangedeventargs e)     {         var frameworkelement = (frameworkelement)dependencyobject;          if ((bool)e.newvalue)         {             frameworkelement.sizechanged += onframeworkelementsizechanged;             updateobservedsizesforframeworkelement(frameworkelement);         }         else         {             frameworkelement.sizechanged -= onframeworkelementsizechanged;         }     }      private static void onframeworkelementsizechanged(object sender, sizechangedeventargs e)     {         updateobservedsizesforframeworkelement((frameworkelement)sender);     }      private static void updateobservedsizesforframeworkelement(frameworkelement frameworkelement)     {         // wpf 4.0 onwards         frameworkelement.setvalue(observedwidthproperty, frameworkelement.actualwidth);         frameworkelement.setvalue(observedheightproperty, frameworkelement.actualheight);          // wpf 3.5 , prior         ////setobservedwidth(frameworkelement, frameworkelement.actualwidth);         ////setobservedheight(frameworkelement, frameworkelement.actualheight);     } }