xaml - Binding and style doesn't work for Win8? -

i derived textbox , called mytextbox. on layoutawarepage created 2 solidcolorbrush props: mybackground , myborder. in xaml of page wrote resourcedictionary style control mytextbox:

 <grid.resources>         <resourcedictionary>             <style targettype="a:mytextbox">                 <setter property="background" value="{binding mybackground}"></setter>                 <setter property="borderbrush" value="{binding myborder}"></setter>                 <setter property="width" value="200"></setter>                 <setter property="isreadonly" value="false"></setter>                 <setter  property="borderbrush" value="3"></setter>             </style>         </resourcedictionary>     </grid.resources> 

when run page can't see control. didn't forget create datacontext page, , properties true colors (not black). idea how solve this?

binding in style setters not supported in winrt.