How can I filter for pagination an ICollectionView once data is filtered?

Question

I have a big dataset,filtered by user criteria with a ICollectionView and I would like to perform data pagination from qualified result.

I supose that I need to ICollectionView one for filtering data and other for pagination. Is this the right way?

The problem is that ICollectionView. Source can't be an other ICollectionView. I've tried some other alternatives but without success.

IEnumerable<foo> data;
ICollectionView MyDataFilter;
...
this.MyDataFilter = CollectionViewSource.GetDefaultView(data);

System.Diagnostics.Debug.Assert(this.MyDataFilter.CanFilter);
this.MyDataFilter.Filter = DataViewFilter;

PaginationView = CollectionViewSource.GetDefaultView(this.MyDataFilter);
this.PaginationView.Filter = PaginationViewFilter;

Answer 1

using the example from How can I paginate a WPF DataGrid?

and simply changing the criteria to take into account the filtering

EG

public class PagingCollectionView : CollectionView
{
    private readonly int _itemsPerPage;

    private int _currentPage = 1;

    public PagingCollectionView(IEnumerable innerList, int itemsPerPage)
        : base(innerList)
    {
        this._itemsPerPage = itemsPerPage;
    }

    public int FilteredCount
    {
        get {return FilteredCollection.Count(); }
    }

    private IEnumerable<object> FilteredCollection => this.SourceCollection.OfType<object>().Where(o=>Filter(o));
    public override int Count
    {
        get
        {
            if (FilteredCount == 0) return 0;
            if (this._currentPage < this.PageCount) // page 1..n-1
            {
                return this._itemsPerPage;
            }
            else // page n
            {
                var itemsLeft = FilteredCount % this._itemsPerPage;
                if (0 == itemsLeft)
                {
                    return this._itemsPerPage; // exactly itemsPerPage left
                }
                else
                {
                    // return the remaining items
                    return itemsLeft;
                }
            }
        }
    }

    public int CurrentPage
    {
        get { return this._currentPage; }
        set
        {
            this._currentPage = value;
            this.OnPropertyChanged(new PropertyChangedEventArgs("CurrentPage"));
        }
    }

    public int ItemsPerPage { get { return this._itemsPerPage; } }

    public int PageCount
    {
        get
        {
            return (FilteredCount + this._itemsPerPage - 1)
                / this._itemsPerPage;
        }
    }

    private int EndIndex
    {
        get
        {
            var end = this._currentPage * this._itemsPerPage - 1;
            return (end > FilteredCount) ? FilteredCount : end;
        }
    }

    private int StartIndex
    {
        get { return (this._currentPage - 1) * this._itemsPerPage; }
    }

    public override object GetItemAt(int index)
    {
        var offset = index % (this._itemsPerPage);
        return this.FilteredCollection.ElementAt(this.StartIndex + offset);
    }

    public void MoveToNextPage()
    {
        if (this._currentPage < this.PageCount)
        {
            this.CurrentPage += 1;
        }
        this.Refresh();
    }

    public void MoveToPreviousPage()
    {
        if (this._currentPage > 1)
        {
            this.CurrentPage -= 1;
        }
        this.Refresh();
    }
}   

To Demo VM:

public class VM:BindableBase
{
    public VM()
    {
        PagingCollectionView = new PagingCollectionView(
            Enumerable.Range(300, 1000).Select(i => i.ToString("X")),
            5);
        PagingCollectionView.Filter = (o) => string.IsNullOrWhiteSpace(Filter) || o.ToString().StartsWith(Filter);

        Next = new DelegateCommand(PagingCollectionView.MoveToNextPage);
        Previous = new DelegateCommand(PagingCollectionView.MoveToPreviousPage );
    }

    private string _Filter;

    public string Filter
    {
        get { return _Filter; }
        set {
            if(SetProperty(ref _Filter, value))
                PagingCollectionView.Refresh();
        }
    }

    public PagingCollectionView PagingCollectionView { get; set; }

    public DelegateCommand Next { get; set; }
    public DelegateCommand Previous { get; set; }
}

XAML:

<Window x:Class="WpfApplication1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApplication1"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.DataContext>
        <local:VM x:Name="vm" />
    </Window.DataContext>

    <DockPanel >
        <TextBox DockPanel.Dock="Top" Text="{Binding Filter}"/>
        <Button DockPanel.Dock="Left" Content="&lt;" Command="{Binding Previous}"  />
        <Button DockPanel.Dock="Right" Content="&gt;" Command="{Binding Next}"/>
        <ListView ItemsSource="{Binding PagingCollectionView}"/>

    </DockPanel>
</Window>

NOTE: this code is not production code just an example to show the process required, it is not robust