private void Newsfeed_SizeChanged(object sender, SizeChangedEventArgs e)
{
ItemsWrapGrid MyItemsPanel = (ItemsWrapGrid)Newsfeed.ItemsPanelRoot;
var width = e.NewSize.Width / 2;
MyItemsPanel.ItemWidth = width;
Messenger.Default.Send(new WidthMessage() { Width = width });
}