FilterControl.BeforeShowValueEditor Event

Fires before displaying an editor used to edit operands in the FilterControl.

Namespace: DevExpress.XtraEditors

Assembly: DevExpress.XtraEditors.v18.2.dll

Declaration

C#

[DXCategory("Events")]
public event ShowValueEditorEventHandler BeforeShowValueEditor

VB.NET

<DXCategory("Events")>
Public Event BeforeShowValueEditor As ShowValueEditorEventHandler

Event Data

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

Property	Description
CurrentNode	Gets the current node in the FilterControl’s tree of criteria.
CustomRepositoryItem	Allows you to specify a custom editor to be opened instead of the default one, specified by the Editor property.
Editor	Gets the currently processed editor. Inherited from ValueEditorEventArgs.
FocusedElementIndex	Gets the index of the current operand value.
OperandValue	Gets the current operand value.
Operation	Gets the operation of the current node.

Remarks

To access the operand value currently being edited and customize the editor used to edit the value, use the parameters provided by the event.

Example

In this example, custom editors are provided to edit value operands in the FilterControl.

The custom editors (SpinEdit and CalcEdit) are supplied by handling the BeforeShowValueEditor event. To supply the editors, corresponding repository items are created and assigned to the event's CustomRepositoryItem parameter.In the example, the FilterControl is used within a GridControl. To get access and subscribe to the FilterControl's BeforeShowValueEditor event, the GridView.FilterEditorCreated event is handled.

The following image shows the result.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-provide-custom-editors-to-edit-value-operands-in-the-filtercontrol-e1519

Form1.cs

        private void gridView1_FilterEditorCreated(object sender, FilterControlEventArgs e) {
            e.FilterControl.BeforeShowValueEditor += 
new ShowValueEditorEventHandler(FilterControl_BeforeShowValueEditor);
        }

        void FilterControl_BeforeShowValueEditor(object sender, ShowValueEditorEventArgs e) {
            if(e.CurrentNode.FirstOperand.PropertyName != "Payment") return;
            RepositoryItemTextEdit item = null;
            if(e.FocusedElementIndex == 2)
                item = new RepositoryItemSpinEdit();
            else
                item = new RepositoryItemCalcEdit();
            item.Mask.MaskType = DevExpress.XtraEditors.Mask.MaskType.Numeric;
            item.Mask.EditMask = "c";
            e.CustomRepositoryItem = item;
        }

Form1.vb

Private Sub gridView1_FilterEditorCreated(ByVal sender As Object, _
ByVal e As FilterControlEventArgs) Handles gridView1.FilterEditorCreated
    AddHandler e.FilterControl.BeforeShowValueEditor, _
    AddressOf FilterControl_BeforeShowValueEditor
End Sub

Private Sub FilterControl_BeforeShowValueEditor(ByVal sender As Object, _
ByVal e As ShowValueEditorEventArgs)
    If e.CurrentNode.FirstOperand.PropertyName <> "Payment" Then
        Return
    End If

    Dim item As RepositoryItemTextEdit = Nothing

    If e.FocusedElementIndex = 2 Then
        item = New RepositoryItemSpinEdit()
    Else
        item = New RepositoryItemCalcEdit()
    End If

    item.Mask.MaskType = DevExpress.XtraEditors.Mask.MaskType.Numeric
    item.Mask.EditMask = "c"

    e.CustomRepositoryItem = item
End Sub

Example

The following code shows how to handle the FilterControl.BeforeShowValueEditor event for a FilterControl being used in the Grid Control. This event fires when an editor used to edit an operand value is invoked. In the example, the editor’s foreground color is modified.

To subscribe to the FilterControl.BeforeShowValueEditor event when using the FilterControl within the Grid Control, the ColumnView.FilterEditorCreated event is handled.

C#

using DevExpress.XtraEditors.Filtering;
using DevExpress.XtraGrid.Views.Base;

private void gridView1_FilterEditorCreated(object sender, FilterControlEventArgs e) {
    e.FilterControl.BeforeShowValueEditor += 
        new ShowValueEditorEventHandler(FilterControl_BeforeShowValueEditor);
}

void FilterControl_BeforeShowValueEditor(object sender, ShowValueEditorEventArgs e) {
    // Set the foreground color to Red
    e.Editor.Properties.Appearance.ForeColor = Color.Red;
}

VB.NET

Imports DevExpress.XtraGrid.Views.Base
Imports DevExpress.XtraEditors.Filtering

Private Sub GridView1_FilterEditorCreated(ByVal sender As System.Object, ByVal e As FilterControlEventArgs) _
Handles GridView1.FilterEditorCreated
    AddHandler e.FilterControl.BeforeShowValueEditor, AddressOf FilterControl_BeforeShowValueEditor
End Sub

Private Sub FilterControl_BeforeShowValueEditor(ByVal sender As Object, ByVal e As ShowValueEditorEventArgs)
    ' Set the foreground color to Red
    e.Editor.Properties.Appearance.ForeColor = Color.Red
End Sub

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the BeforeShowValueEditor event.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

winforms-filtercontrol-assign-custom-editors-to-value-operands/CS/CustomEditor/Form1.cs#L31

private void gridView1_FilterEditorCreated(object sender, FilterControlEventArgs e) {
    e.FilterControl.BeforeShowValueEditor += FilterControl_BeforeShowValueEditor;
}

how-to-create-a-complex-filter-that-uses-mathematic-calculations-for-gridview-e2800/CS/WindowsApplication1/ComplexFilterHelper.cs#L82

{
    e.FilterControl.BeforeShowValueEditor += FilterControl_BeforeShowValueEditor;
}

VB.NET

winforms-filtercontrol-assign-custom-editors-to-value-operands/VB/CustomEditor/Form1.vb#L35

Private Sub gridView1_FilterEditorCreated(ByVal sender As Object, ByVal e As FilterControlEventArgs)
    AddHandler e.FilterControl.BeforeShowValueEditor, AddressOf FilterControl_BeforeShowValueEditor
End Sub

how-to-create-a-complex-filter-that-uses-mathematic-calculations-for-gridview-e2800/VB/ComplexFilterHelper.vb#L80

Private Sub _View_FilterEditorCreated(ByVal sender As Object, ByVal e As FilterControlEventArgs)
    AddHandler e.FilterControl.BeforeShowValueEditor, AddressOf FilterControl_BeforeShowValueEditor
End Sub