c# - LongListSelector cannot change ItemsSource -

i can't seem able change itemssource in longlistselector. after doing research, appears longlistselector ignores changes in itemssource. correct?g if yes, there workaround?

this i'm trying do. have option sort city list either country or cities. this:

var groupbycountry = city in app.viewmodelcity.items                                 group city city.groupbycountry c                                 orderby c.key                                 select new group<currency>(c.key, c);  var groupbycity = city in app.viewmodelcity.items                                 group city city.groupbycity c                                 orderby c.key                                 select new group<city>(c.key, c); 

so both same, grouping different. idea simple change itemssource either groupbycountry or groupbycity, depending on user choice. unfortunately, changing itemssource has no effect. won't update. when app restarted (with preferred source stored) longlistselector updated.

so there way force longlistselector update itemssource? if not, workaround?

i develop in wp7, set itemsource null before real assignment ui update new itemsource.

longlistselectora.itemssource = null; binding b; b = new binding("collectioninviewmodel"); longlistselectora.setbinding(longlistselector.itemssourceproperty, b); 

give shot, wish luck. :)