Question

I am trying to create a scheduler in WPF. I have a central static list in main window, which is initialized on load by a backgroundworker. There also is a dispatchtimer in mainwindow, whose interval is recalculated everytime the list changes.

public static List<ListViewcls> TODOdatalst = null;
public static void RefreshdblList()
{
    if (ApplicationState.GetValue<bool>("dbDetected"))
    {
        TODOdatalst = DataAccess.ReadAllTODODataFromDataBase();
        InitialiseDailyReminders();
    }
}

Now there is another window which contains a listview which is bound to an observable collection, which is derived from the static list in mainwindow. whenever an item is added, updated or deleted from the list, the list in both the windows is manually refreshed via static functions.

private static readonly ObservableCollection<ListViewcls> TO_DOViewlst = new ObservableCollection<ListViewcls>();
public void RefreshView()
{
    MainWindow.RefreshdblList();
    if (MainWindow.TODOdatalst != null)
        InitialiseListView(MainWindow.TODOdatalst);
    else
        InitialiseListView(DataAccess.ReadAllTODODataFromDataBase());
}

so is this approach proper ?? It works for now but suppose in the future, i have one more window which will also access the list but then i will be managing the refresh of data between 3 windows….that does not figure right. Anyone can suggest some better way, that i can keep a central repository and whenever it is updated all other lists get updated.

Answer 1

When one uses MVVM there is an option to use one ViewModel (the class which acquires and holds the data which is used as Data Contexts for a window/page(s)) between multiple windows and this scenario is common.

I would opt to share the instantiated ViewModel (or class which houses your data) between all windows and pass it in during window creation to have the window/page’s data context bound to that one VM. That way the satellite window(s) are using the same data as the main and not having to do any update tricks as shown. Plus any new windows simply bind to the observable collection which everyone else is binding to.