FilterBehavior.CustomUniqueValues Event

Allows you to specify unique values displayed within a filter element.

Namespace: DevExpress.Xpf.Core.FilteringUI

Assembly: DevExpress.Xpf.Grid.v24.2.dll

NuGet Package: DevExpress.Wpf.Grid.Core

Declaration

C#

public event EventHandler<CustomUniqueValuesEventArgs> CustomUniqueValues

VB.NET

Public Event CustomUniqueValues As EventHandler(Of CustomUniqueValuesEventArgs)

Event Data

The CustomUniqueValues event's data class is CustomUniqueValuesEventArgs. The following properties provide information specific to this event:

Property	Description
CountedValues	Gets or sets unique filter values with their counts.
FieldName	Gets a name of the field.
Filter	Gets the current filter criteria specified in the Filter Editor / Filter Element.
Values	Gets or sets unique filter values.

Remarks

Run Demo: FilterBehavior - ViewModel Data Filtering

Xaml

<dxfui:FilterBehavior x:Name="filterBehavior" ItemsSource="{x:Type local:ProductInfo}"
                      CustomUniqueValues="filterBehavior_CustomUniqueValues" /> 

C#

void filterBehavior_CustomUniqueValues(object sender, CustomUniqueValuesEventArgs e) {
    if(e.FieldName != "CategoryName")
        throw new InvalidOperationException();
    e.CountedValues = GetCategoryUniqueValues();
}

internal IList<CountedValue> GetCategoryUniqueValues() {
    return GetProductsQueryCore()
        .GroupBy(x => x.CategoryName)
        .Select(x => new { x.Key, Count = x.Count() })
        .ToList()
        .Select(x => new CountedValue(x.Key, x.Count))
        .ToList();
}

VB.NET

Private Sub filterBehavior_CustomUniqueValues(ByVal sender As Object, ByVal e As CustomUniqueValuesEventArgs)
    If e.FieldName <> "CategoryName" Then Throw New InvalidOperationException()
    e.CountedValues = GetCategoryUniqueValues()
End Sub

Friend Function GetCategoryUniqueValues() As IList(Of CountedValue)
    Return GetProductsQueryCore().GroupBy(Function(x) x.CategoryName).[Select](Function(x) New With {x.Key, Key
        .Count = x.Count()
    }).ToList().[Select](Function(x) New CountedValue(x.Key, x.Count)).ToList()
End Function