c# - Empty first value on two comboboxes updating one another -

fairly new c# , xaml have patience! have 2 comboboxes, values shown in each dependent on 1 another. used displaymemberpath , selectedmemberpath so:

<combobox selectedindex="-1" x:name="siteloccombo" selectedvaluepath="generalarea" displaymemberpath="station" itemsource="{binding}"/> <combobox selectedindex="-1" x:name="sitecodecombo" selectedvaluepath="station" displaymemberpath="generalarea" itemsource="{binding}"/> 

to first value in comboboxes added property issynchronizedwithcurrentitem=true comboboxes not update each other

if want second combo track first combo's selected value...

<combobox selectedindex="-1"                    x:name="siteloccombo"                    selectedvaluepath="generalarea"                    displaymemberpath="station"                    itemsource="{binding}"/>         <combobox selectedindex="-1"                    x:name="sitecodecombo"                    selectedvaluepath="station"                    displaymemberpath="generalarea"                    itemsource="{binding}"                   selectedvalue="{binding elementname=siteloccombo, path=selectedvalue}"                   /> 

or alternatively, can bind selectedindex, or selecteditem, etc in same way. works case both binding same itemssource, otherwise you'll need converter or property in viewmodel.