wpftoolkit - Change windows phone toolkit pushpin content -

how change content of toolkit pushpin via program dynamically?

i've put several pushpins on maps on initializing, , want change content of pushpin while user put tap on it.

this xaml code:

<toolkit:mapextensions.children>     <toolkit:mapitemscontrol x:name="mapitems">         <toolkit:mapitemscontrol.itemtemplate>             <datatemplate>                 <toolkit:pushpin geocoordinate="{binding coordinate}" tap="pinontap">                     <toolkit:pushpin.template>                         <controltemplate targettype="toolkit:pushpin">                             <stackpanel>                                 <contentpresenter x:name="content" horizontalalignment="center" content="{templatebinding content}" />                                 <path data="m0,0 l0,1 l1,0" fill="{templatebinding background}" stretch="fill" margin="32,0" height="12" width="18"                                     visibility="{binding content.visibility, mode=twoway, relativesource={relativesource templatedparent}}"                                     horizontalalignment="left" />                                 <image source="{binding icon_img}" stretch="none" horizontalalignment="left"/>                             </stackpanel>                         </controltemplate>                     </toolkit:pushpin.template>                     <border background="white" visibility="collapsed" width="200" horizontalalignment="center" >                         <stackpanel orientation="horizontal" tap="gotoprofilefrompin">                             <image margin="8" source="{binding image}" verticalalignment="top" width="50" height="50" />                             <stackpanel>                                 <textblock text="{binding uid}" visibility="collapsed"/>                             </stackpanel>                         </stackpanel>                     </border>                 </toolkit:pushpin>             </datatemplate>         </toolkit:mapitemscontrol.itemtemplate>     </toolkit:mapitemscontrol> </toolkit:mapextensions.children> 

and program.cs:

private void pinontap(object sender, system.windows.input.gestureeventargs e) {     var popout = ((sender pushpin).content) border;     popout.visibility = system.windows.visibility.visible;      var popoutimg = (popoutnew.child stackpanel).datacontext;      var popuser = popoutimg userpin;      // function images uid      popuser.image = new uri(images fetch function, urikind.relativeorabsolute);      popoutnew.child.updatelayout();      e.handled = true; } 

in pinontap function, i'll fetch picture function , show on maps toolkit:pushpin.content, can't work.

this code:

popuser.image = new uri(images fetch function, urikind.relativeorabsolute); 

it change image source not update ui. print it's value , source has been changed, donno why didn't appear on map (the map show "border" white background , didn't have image inside it)

i think have implement inotifypropertychange th change not reflected on xaml .