I have not been able to define the SfDataGrid ItemSource in XAML because the ObservableCollection is not populated in the ViewModel before the Views XAML runs. Use of XAML DynamicResource does not help. I can work around this problem by defining the ItemSource in code because this allows for making this definition after the ObservableCollection is populated. This issue points to another issue that I cannot work around. That other issue is that I cannot see the content of the SfDataGrid change when I add or delete records in the ObservableCollection. I am using the latest Syncfusion WPF (May 3, 2016) on VS 2015.
I have none of these problems using the WPF DataGrid that comes standard. With that I can add or delete row programmatically and view the changes in the View and it works even with XAML StaticResource.
I have attached a simple version of the code to demonstrate these points. It show two data grids (SfDataGrid & standard DataGrid) and it has an "Add New" button that adds a record to the ObservableCollection. The "Add New" button was put there to demonstrate how the view changes a record is added to ObservableCollection.
Thank You,for your help,