How to: Sort Filter Drop-Down Items in a Custom Manner

• Aug 01, 2019
• 2 minutes to read

The following example demonstrates how to sort filter drop-down items in a custom manner.

In this example, the CustomFilterPopupItems event is handled to manage a list of filter items. This event is raised when an end-user invokes the filter drop-down. The event parameter provides access to the filter items list, which is then sorted by the length of the items' captions (if the corresponding option is selected).

MainWindow.xaml.vb

Imports Microsoft.VisualBasic
Imports System.Collections
Imports System.Windows
Imports DevExpress.Xpf.PivotGrid
Imports DevExpress.XtraPivotGrid.Data
Imports DXPivotGrid_CustomFilterItemsSorting.DataSet1TableAdapters

Namespace DXPivotGrid_CustomFilterItemsSorting
    Partial Public Class MainWindow
        Inherits Window
        Private salesPersonDataTable As New DataSet1.SalesPersonDataTable()
        Private salesPersonDataAdapter As New SalesPersonTableAdapter()
        Public Sub New()
            InitializeComponent()
            pivotGridControl1.DataSource = salesPersonDataAdapter.GetData()
        End Sub
        Private Sub pivotGridControl1_CustomFilterPopupItems(ByVal sender As Object, _
                ByVal e As PivotCustomFilterPopupItemsEventArgs)
            If rbCaptionLength.IsChecked = True Then
                ArrayList.Adapter(CType(e.Items, IList)).Sort(New FilterItemsComparer())
            End If
        End Sub
    End Class
    Public Class FilterItemsComparer
        Implements IComparer
        Private Function IComparer_Compare(ByVal x As Object, ByVal y As Object) As Integer _
                            Implements IComparer.Compare
            If Not(TypeOf x Is PivotGridFilterItem) OrElse _
                Not(TypeOf y Is PivotGridFilterItem) Then
                Return 0
            End If
            Dim item1 As PivotGridFilterItem = CType(x, PivotGridFilterItem)
            Dim item2 As PivotGridFilterItem = CType(y, PivotGridFilterItem)
            If item1.ToString().Length = item2.ToString().Length Then
                Return 0
            End If
            If item1.ToString().Length > item2.ToString().Length Then
                Return 1
            End If
            Return -1
        End Function
    End Class
End Namespace

MainWindow.xaml

<Window xmlns:dxpg="http://schemas.devexpress.com/winfx/2008/xaml/pivotgrid"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        x:Class="DXPivotGrid_CustomFilterItemsSorting.MainWindow"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Height="500" Width="550" Title="Main Window">
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition />
        </Grid.RowDefinitions>
        <GroupBox Header="Sort Filter Items" Margin="5">
            <StackPanel Orientation="Vertical">
                <RadioButton x:Name="rbAlphabetically" Content="Alphabetically" Margin="0,5,0,2"
                             IsChecked="True" />
                <RadioButton x:Name="rbCaptionLength" Content="By Caption Length" Margin="0,2,0,5" />
            </StackPanel>
        </GroupBox>
        <dxpg:PivotGridControl CustomFilterPopupItems="pivotGridControl1_CustomFilterPopupItems"
                               Name="pivotGridControl1" Grid.Row="1">
            <dxpg:PivotGridControl.Fields>
                <dxpg:PivotGridField Name="fieldYear" FieldName="OrderDate" Area="ColumnArea"
                                     Caption="Year" GroupInterval="DateYear" />
                <dxpg:PivotGridField Name="fieldProductName" FieldName="ProductName" Area="RowArea"
                                     Caption="Product Name" />
                <dxpg:PivotGridField Name="fieldQuantity" FieldName="Quantity" Area="DataArea" />
            </dxpg:PivotGridControl.Fields>
        </dxpg:PivotGridControl>
    </Grid>
</Window>

MainWindow.xaml.cs

using System.Collections;
using System.Windows;
using DevExpress.Xpf.PivotGrid;
using DevExpress.XtraPivotGrid.Data;
using DXPivotGrid_CustomFilterItemsSorting.DataSet1TableAdapters;

namespace DXPivotGrid_CustomFilterItemsSorting {
    public partial class MainWindow : Window {
        DataSet1.SalesPersonDataTable salesPersonDataTable = new DataSet1.SalesPersonDataTable();
        SalesPersonTableAdapter salesPersonDataAdapter = new SalesPersonTableAdapter();
        public MainWindow() {
            InitializeComponent();
            pivotGridControl1.DataSource = salesPersonDataAdapter.GetData();
        }
        private void pivotGridControl1_CustomFilterPopupItems(object sender,
                                    PivotCustomFilterPopupItemsEventArgs e) {
            if (rbCaptionLength.IsChecked == true)
                ArrayList.Adapter((IList)e.Items).Sort(new FilterItemsComparer());
        }
    }
    public class FilterItemsComparer : IComparer {
        int IComparer.Compare(object x, object y) {
            if (!(x is PivotGridFilterItem) || !(y is PivotGridFilterItem)) return 0;
            PivotGridFilterItem item1 = (PivotGridFilterItem)x;
            PivotGridFilterItem item2 = (PivotGridFilterItem)y;
            if (item1.ToString().Length == item2.ToString().Length) return 0;
            if (item1.ToString().Length > item2.ToString().Length) return 1;
            return -1;
        }
    }
}