Wpf Observable集合和DataGrid不更新更改

I have an observable collection in the view model that implements Bindable Base as follows Please have a look at the MoveUp and MoveDown methods where they are bound to two buttons in the view. When ever up button is pressed I want the selected row in the datagrid to move one step up in the based on the sequence column in the database and for down one step down.. Both the methods works PERFECTLY. Problem is the changes get shown in the datagrid only when the entire view is refreshed. My requirement is when the button is clicked I want the view to be automatically refreshed. I apologize for such long code. Please Help!!!!. I have some cs code as well for the both up and down buttons specified below the viewmodel. Only pointers in the code that needs to be emphasized is the ObservableCollection JobEntities, MoveUp and MoveDown commands.I have an observable collection in the view mod