OperatorItemBase.OperandTemplate Property

Gets or sets a template that specifies an editor for the operands.

Namespace: DevExpress.Xpf.Core.FilteringUI

Assembly: DevExpress.Xpf.Grid.v24.1.Core.dll

NuGet Package: DevExpress.Wpf.Grid.Core

Declaration

C#

public DataTemplate OperandTemplate { get; set; }

VB.NET

Public Property OperandTemplate As DataTemplate

Property Value

Type	Description
DataTemplate	A template that specifies an editor for the operands.

Remarks

Run Demo: Filter Editor - Customize Operands

The Filter Editor automatically creates operand editors based on the field and operator type. You can customize operand editors.

The following code sample specifies the TrackBarEdit as an operand for the Between and NotBetween operators:

1. Create a template for the operands. The following models depend on the operator type. Use their properties to bind to operand values in the template:

   • ConstantFilterModel (e.g., Is null, Is Yesterday)
   • BinaryFilterModel (e.g., Equals, Is greater than)
   • TernaryFilterModel (e.g., Is between, Is between dates)
   • VariadicFilterModel (e.g., Is any of, Is none of)
   Xaml

   <UserControl.Resources>
       <DataTemplate x:Key="ternaryTemplate">
           <dxe:TrackBarEdit Minimum="0" Maximum="300" MinWidth="120" 
                             TickPlacement="None" dxfui:FilterEditorNavigation.Index="0">
               <dxe:TrackBarEdit.EditValue>
                   <MultiBinding Converter="{local:TrackBarEditRangeConverter}">
                       <Binding Path="Left"/>
                       <Binding Path="Right"/>
                   </MultiBinding>
               </dxe:TrackBarEdit.EditValue>
               <dxe:TrackBarEdit.StyleSettings>
                   <dxe:TrackBarRangeStyleSettings />
               </dxe:TrackBarEdit.StyleSettings>
           </dxe:TrackBarEdit>
       </DataTemplate>
   </UserControl.Resources>
   

   TrackBarEditRangeConverter

   C#

   public class TrackBarEditRangeConverter : BaseMultiValueConverter {
       public override object Convert(object[] values, Type targetType, object parameter, CultureInfo culture) {
           if(values.Length != 2)
               return new TrackBarEditRange();
           return new TrackBarEditRange(GetApproptiateValue(values[0]), GetApproptiateValue(values[1]));
       }
   
       short GetApproptiateValue(object value) {
           if(value is int)
               return System.Convert.ToInt16(value);
           return value is short ? (short)value : (short)0;
       }
   
       public override object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture) {
           var trackBarEditRange = value as TrackBarEditRange;
           if(trackBarEditRange == null)
               return new object[] { (short)0, (short)0 };
           return new object[] { (short)trackBarEditRange.SelectionStart, (short)trackBarEditRange.SelectionEnd };
       }
   } 
   

   VB.NET

   Public Class TrackBarEditRangeConverter
   Inherits BaseMultiValueConverter
   
       Public Overrides Function Convert(ByVal values As Object(), ByVal targetType As Type, ByVal parameter As Object, ByVal culture As CultureInfo) As Object
           If values.Length <> 2 Then Return New TrackBarEditRange()
           Return New TrackBarEditRange(GetApproptiateValue(values(0)), GetApproptiateValue(values(1)))
       End Function
   
       Private Function GetApproptiateValue(ByVal value As Object) As Short
           If TypeOf value Is Integer Then Return System.Convert.ToInt16(value)
           Return If(TypeOf value Is Short, CShort(value), CShort(0))
       End Function
   
       Public Overrides Function ConvertBack(ByVal value As Object, ByVal targetTypes As Type(), ByVal parameter As Object, ByVal culture As CultureInfo) As Object()
         Dim trackBarEditRange = TryCast(value, TrackBarEditRange)
           If trackBarEditRange Is Nothing Then Return New Object() {CShort(0), CShort(0)}
           Return New Object() {CShort(trackBarEditRange.SelectionStart), CShort(trackBarEditRange.SelectionEnd)}
       End Function
   End Class 
   

2. Handle the FilterEditorControl.QueryOperators event, get the operator, and assign the created template to the OperandTemplate property.

   Xaml

   <dxg:TableView x:Name="view">
       <dxg:TableView.FilterEditorTemplate>
           <DataTemplate>
               <dxfui:FilterEditorControl QueryOperators="OnQueryOperators" />
           </DataTemplate>
       </dxg:TableView.FilterEditorTemplate>
   </dxg:TableView> 
   

   C#

   void OnQueryOperators(object sender, FilterEditorQueryOperatorsEventArgs e) {
       if(e.FieldName == "Quantity") {
           var template = (DataTemplate)FindResource("ternaryTemplate");
           e.Operators[FilterEditorOperatorType.Between].OperandTemplate = template;
           e.Operators[FilterEditorOperatorType.NotBetween].OperandTemplate = template;
       }
   } 
   

   VB.NET

   Private Sub OnQueryOperators(ByVal sender As Object, ByVal e As FilterEditorQueryOperatorsEventArgs)
       If e.FieldName = "Quantity" Then
           Dim template = CType(FindResource("ternaryTemplate"), DataTemplate)
           e.Operators(FilterEditorOperatorType.Between).OperandTemplate = template
           e.Operators(FilterEditorOperatorType.NotBetween).OperandTemplate = template
       End If
   End Sub