使用Linq将xml解析为ObservableCollection。使用wpf c＃绑定到datagrid的数据

I'm new to linq, wpf and C#. I've managed to research my way to a functional component. I have attacked data binding successfully but I'm struggling with performance. I'm reading in a static external xml file (i.e. database) and want to display it to users using a wpf datagrid. The additional bit of info is that I'm using a user-controlled wpf combobox to filter how much data from the database is shown in the grid. I'd like to use linq to accomplish this task but I can't seem to get it to perform correctly.I'm new to linq, wpf and C#. I've managed to re