caliburn.micro - Event Pass element source with short syntax -

this method worked button event passed treeview element viewmodel short syntax event not passed, problem? thanks.

<button content="search in treeview" height="34" width="100">     <i:interaction.triggers>         <i:eventtrigger eventname="click">             <cal:actionmessage methodname="searchtreeview">                 <cal:parameter value="{binding elementname=treeview}" />             </cal:actionmessage>         </i:eventtrigger>     </i:interaction.triggers> </button> <treeview x:name="treeview" itemssource="{binding treeviewsource}"/> 

short syntax event

<button x:name="searchtreeview" content="search in treeview" cal:message.attach="[event click] = [action searchtreeview($source.treeview)]" />  <treeview x:name="treeview" itemssource="{binding treeviewsource}"/> 

you don't need specify $source.treeview, name of element, treeview enough

<button x:name="searchtreeview" content="search in treeview" cal:message.attach="[event click] = [action searchtreeview(treeview)]" />  <treeview x:name="treeview" itemssource="{binding treeviewsource}"/> 

that said, it's not idea pass control viewmodel. if want the selected item, should bind treeview's selecteditem property property on viewmodel , access searchtreeview method, eg

<button x:name="searchtreeview" content="search in treeview" cal:message.attach="[event click] = [action searchtreeview()]" />  <treeview x:name="treeview" itemssource="{binding treeviewsource}" selecteditem={binding myselecteditem}"/>