I am creating an application that consists of multiple patterns and frameworks which include, MVVM, Singleton pattern and entity framework within one WPF application.
My application consists of two aspects; A School and a Course. Due to the use of the singleton pattern, I have the following ViewModels;
SchoolListVM -> SchoolVM -> CourseVm
I am trying to implement a simple `filter` to enable a user to search through a listview within my view, shown below.
As you can see, I have a filter to search through a the list of Schools and currently trying to implement a filter to search through the list of courses; but this is where my problem lies.
I have been following
this link here to help me implement a filter and changed it to suit the needs of my application.
However, when I implement this I get two problems:
The first issue is when I bind my ObservableCollection to the ItemSource within my view (for the course list), nothing seems to display.
The second issue is that get the following error;
Object reference not set to an instance of an object.
This is produced when I call View.Refresh();
I have put together a sample application to represent my problem that I encounter, which can be found here - ListviewSearch
Could anyone please help me in trying to solve this issue?
Many thanks in advance.