This example illustrates how to add chips with predefined filters (and apply pre-defined filters against data displayed in the DevExpress .NET MAUI CollectionView control).

Related Controls and Their Properties:

• FilterChipGroup: ItemsSource, SelectedItems, DisplayMember
• DXCollectionView: ItemsSource, FilterString, ItemTemplate

• This project uses the FilterChipGroup control to display chips with predefined filters. The FilterChipGroup.ItemsSource property is bound to the PredefinedFilters collection. Each item in this collection contains a value and corresponding display text. The value is specified using Criteria Language Syntax.

  <dxe:FilterChipGroup ItemsSource="{Binding PredefinedFilters}" SelectedItems="{Binding SelectedFilters, Mode=TwoWay}"

  public class MainViewModel : BindableBase {
      string filter;
      public ObservableCollection<FilterItem> PredefinedFilters {
          get;
          set;
      }
      public BindingList<FilterItem> SelectedFilters {
          get;
          set;
      }
      public MainViewModel() {
          SelectedFilters = new BindingList<FilterItem>();
          PredefinedFilters = new ObservableCollection<FilterItem>() {
              new FilterItem(){ DisplayText= "Today", Filter = "IsOutlookIntervalToday([CreatedDate])" },
              new FilterItem(){ DisplayText= "Last Week", Filter = "IsThisWeek([CreatedDate])" },
              new FilterItem(){ DisplayText= "Drafts", Filter = "[IsDraft] == True" },
              new FilterItem(){ DisplayText= "< $1000", Filter = "[Price] < 1000" },
              new FilterItem(){ DisplayText= "> $4000", Filter = "[Price] > 4000" },
          };
  }

• The FilterChipGroup.SelectedItems property returns a BindingList. You can handle the BindingList.ListChanged event to update a filter condition. In the event handler, create the filter string and pass it to the FilterString property.

  <dxcv:DXCollectionView FilterString="{Binding Filter, Mode=TwoWay}" ... 

  public class MainViewModel : BindableBase 
      string filter;
      public BindingList<FilterItem> SelectedFilters {
          get;
          set;
      }
      public string Filter {
          get {
              return filter;
          }
          set {
              filter = value;
              RaisePropertiesChanged();
          }
      }
      private void SelectedFiltersChanged(object sender, ListChangedEventArgs e) {
          if (SelectedFilters.Count > 0)
              Filter = String.Join(" AND ", SelectedFilters.Select(f => f.Filter));
          else
              Filter = string.Empty;
      }
  }