OperatorItemBase.OperandTemplate Property

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

Namespace: DevExpress.Xpf.Core.FilteringUI

Assembly: DevExpress.Xpf.Grid.v20.1.Core.dll

Declaration

public DataTemplate OperandTemplate { get; set; }
Public Property OperandTemplate As DataTemplate

Property Value

Type Description
DataTemplate

A template that specifies an editor for the operands.

Remarks

TIP

Demo: Filter Editor - Customize Operands

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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:

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

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