xaml - Bound Item To DependencyProperty Not Propagating Value -

this property defined inside custombutton:

 public bool ison     {          { return (bool)getvalue(isonproperty); }         set          {              setvalue(isonproperty, value);             if (ison)                  visualstatemanager.gotostate(this, "on", true);             else                  visualstatemanager.gotostate(this, "off", true);         }     }     public static readonly dependencyproperty isonproperty =         dependencyproperty.register("ison",                                      typeof(bool),                                      typeof(imagebutton),                                      new propertymetadata(false)); 

in xaml bound boolean list below:

ison="{binding sender.ispinned, mode=oneway}" 

and sender.ispinned raises propertychange

public bool ispinned          {             { return _model.ispinned; }             set              {                  _model.ispinned = value;                 raisepropertychanged("ispinned");             }         }   protected void raisepropertychanged(string propertyname)         {             propertychangedeventhandler handler = propertychanged;             if (handler != null)             {                 handler(this, new propertychangedeventargs(propertyname));             }         }          public event propertychangedeventhandler propertychanged; 

when ispinned changed, ison doesn't see change @ all. when save data , refresh ui, change reflected on ison.

it seems propertychangedeventhandler not implemented when debugged, calls event.

i believe code (not shown) changing _model.ispinned directly , not changing ispinned property has binding notification. lead update failure ison.

the backing variable _model.ispinned used ispinned cannot changed other ispinned setter; such change can noticed ison.

one has change ispinned property directly (which subsequently changes _model.ispinned) otherwise binding cannot pick on changes backing store _model.ispinned.

-- or ---

when variable _model.ispinned changed outside of setter, call raisepropertychanged("ispinned"); signify change ison.