wpf - DataGrid.RowStyle only works on initial binding -

i have datatrigger applying style visibility property of datagrid row. datatrigger working fine on initial binding of datagrid (ie - sets row visibility collapsed if filteredout true).

i have combobox sets filteredout property true or false each item in observablecollection allpartmalfunctions depending upon user has selected in combobox.

here problem: after selecting item in combobox , setting filteredout property each item, the datagrid rows not refresh visible or collapsed , on ui looks same did before selecting in combobox. missing?

here xaml:

<datagrid itemssource="{binding allpartmalfunctions}"           autogeneratecolumns="false" width="auto">     <datagrid.rowstyle>         <style targettype="datagridrow">             <style.triggers>                 <datatrigger binding="{binding filteredout, mode=twoway}" value="true">                     <setter property="visibility" value="collapsed" />                 </datatrigger>                 <datatrigger binding="{binding filteredout, mode=twoway}" value="false">                     <setter property="visibility" value="visible" />                 </datatrigger>             </style.triggers>         </style>     </datagrid.rowstyle>     <datagrid.columns>          <!--removed brevity-->     </datagrid.columns> </datagrid> 

here viewmodel datagrid binding:

public class malfunctions : viewmodelbase {        public observablecollection<model.partmalfunction> allpartmalfunctions {             get;             private set;         } } 

here partmalfunction model:

public class partmalfunction {     private bool _filteredout = false;     public bool filteredout {             {                 return _filteredout;             }             set {                 _filteredout = value;             }         }     } 

class "partmalfucntion" needs implement system.componentmodel.inotifypropertychanged , fire off propertychanged event when filteredout's value changed.

public class partmalfunction : system.componentmodel.inotifypropertychanged {     #region inotifypropertychanged members     public event system.componentmodel.propertychangedeventhandler propertychanged;     #endregion      private bool _filteredout = false;     public bool filteredout     {         {             return _filteredout;         }         set {             _filteredout = value;             if (propertychanged != null)                 propertychanged(this, new system.componentmodel.propertychangedeventargs("filteredout"));         }     } }