vb.net - DBContext.ChangeTracker not detecting changes to an Array -

my ef6 project in vb.net maps mysql database using following mapping:

partial public class workrule      public property workruleid integer 'maps int     public property description string 'maps tinytext     public property regulartime byte() 'maps tinyblob end class 

if edit description textbox, changes detected , saved expected upon calling .savechanges. however, if edit content of 1 of textboxes bound array element, bound element changed change not detected dbcontext.changetracker , changes not saved database upon calling .savechanges.

i can force save manually setting dbcontext.entry().state=entitystate.modified there better way changes array elements automatically detected? should using other array perhaps?

code follows:

xaml:

    <grid>         <grid.columndefinitions>             <columndefinition width="*"/>             <columndefinition width="*"/>         </grid.columndefinitions>         <listbox x:name="lstworkrules"/>         <stackpanel grid.column="1" datacontext="{binding elementname=lstworkrules, path=selecteditem}">             <label>description:</label>             <textbox text="{binding path=description}"/>             <label>day 1:</label>             <textbox text="{binding path=regulartime[0]}"/>             <label>day 2:</label>             <textbox text="{binding path=regulartime[1]}"/>             <label>etc.</label>             <button click="button_click">save</button>         </stackpanel>      </grid> 

vb:

imports system.data.entity  class mainwindow     dim wrcontext workruleentities      private sub window_loaded(sender object, e routedeventargs)         wrcontext = new workruleentities         wrcontext.workrules.load          lstworkrules.itemssource = wrcontext.workrules.local         lstworkrules.displaymemberpath = "description"     end sub      private sub button_click(sender object, e routedeventargs)         wrcontext.savechanges()     end sub end class