更新另一个ObservableCollection的结果的ObservableCollection

Question

Excuse me but I didn't know how to formulate the question :

I have two ObservableCollection

ObservableCollection MyMainList is the ObservableCollection where are stored all of my objects.

ObservableCollection<T> MyFilteredList = new ObservableCollection(MyMainList.Where(x=>Condition))

is the ObservableCollection filtered according some parameters.

At one moment, I need to add or remove objects from MyMainList, but then MyFilteredList is not updated automatically.

I need always to do :

MyMainList.Add(newObject);
MyFilteredList.Add(newObject);

Is there a way to do all of that in just one line, so when I modify MyMainList, MyFilteredList will be automatically updated?

Edit : To answer to Adriano Repetti, when I open my window, I load all of objects (so I don't need to reload my DB everytime I change filters). I have three different filters : - 1 combobox "Affaire" (list of the contracts) - 1 combobox "Phase" (list of the subcontracts) - 1 TextBox "Filter" ( if I want to see only objects whose name contains that text).

When I change selection of 1st ComboBox, I update the list of subcontracts, and update the filtered list of assemblies.

private Affaire selectedAffaire;
public Affaire SelectedAffaire
{
   get { return selectedAffaire; }
   set
   {
      selectedAffaire = value;
      this.NotifyPropertyChanged("SelectedAffaire");
      if (value != null)
      {
         GetListPhaseInContract(); //I update the list of subcontracts in 2nd Combobox
      }
      UpdateListAssemblages(); // I update MyFilteredList
   }
}

When I change selection of 2nd ComboBox (subcontract), I update the list of MyFilteredList

private Phase selectedPhase;
public Phase SelectedPhase
{
   get { return selectedPhase; }
   set
   {
       selectedPhase = value;
       this.NotifyPropertyChanged("SelectedPhase");
       UpdateListAssemblages();
   }
}

Then when I change my TextBox value, I also update the list

private string texteFiltre;
public string TexteFiltre
{
   get { return texteFiltre; }
   set
   {
      texteFiltre = value;
      this.NotifyPropertyChanged("TexteFiltre");
      UpdateListAssemblages();
   }
}

If I understood, this post is what I need to look for? I don't know yet what are ICollectionView, but I guess I need to look in that way?Will I gain some execution time using ICollectionView? as I see I need anyway to Refresh it?

Answer 1

Since you didn't give us the detial of the data struct, I just assume that PhaseInContract is included in MainList . So, just simply create two views for your MainList , then binding them to UI. All views will synchronize with source automatically.

Public ICollectionView MainListView;
Public ICollectionView PhaseInContractView;
Public ObservableCollection<YourDataClass> MainList;

public YourViewModel()
{
    MainList = new ObservableCollection<YourDataClass>();

    // Load datas form db and fill MainList

    MainListView = new CollectionViewSource() { Source = MainList }.View;
    MainListView.Filter = (x) =>
    {
        // your MainListView filtering logic.
    };

    PhaseInContractView = new CollectionViewSource() { Source = MainList }.View;
    PhaseInContractView.Filter = (x) =>
    {
        // your PhaseInContractView filtering logic
    };

private Affaire selectedAffaire;
public Affaire SelectedAffaire
{
    get { return selectedAffaire; }
    set
    {
        selectedAffaire = value;
        this.NotifyPropertyChanged("SelectedAffaire");
        if (value != null)
        {
           PhaseInContractView.Refresh();
        }
        MainListView.Refresh();
    }
}

// And other properties.
...