ASPxGridView.CustomGroupDisplayText Event

Enables you to provide custom content for group rows.

Namespace: DevExpress.Web

Assembly: DevExpress.Web.v19.1.dll

Declaration

C#

public event ASPxGridViewColumnDisplayTextEventHandler CustomGroupDisplayText

VB.NET

Public Event CustomGroupDisplayText As ASPxGridViewColumnDisplayTextEventHandler

Event Data

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

Property	Description
Column	Gets the data column that contains the cell currently being processed.
DisplayText	Enables you to set a custom text for the cell currently being processed. Inherited from ASPxGridColumnDisplayTextEventArgs.
EncodeHtml	Gets or sets a value that specifies whether the cell display text keeps any of its values that are HTML as HTML, or instead, strips out the HTML markers. Inherited from ASPxGridColumnDisplayTextEventArgs.
Value	Gets the edit value of the cell currently being processed. Inherited from ASPxGridColumnDisplayTextEventArgs.
VisibleIndex	Gets the visible index of the data item (row, card or record) where the processed cell resides. Inherited from ASPxGridColumnDisplayTextEventArgs.
VisibleRowIndex	Obsolete. Gets the visible index of the data row where the processed cell resides.

The event data class exposes the following methods:

Method	Description
GetFieldValue(Int32, String)	Returns the value of the specified data source field in the specified data item (row, card or record). Inherited from ASPxGridColumnDisplayTextEventArgs.
GetFieldValue(String)	Returns the value of the specified data source field in the current data item (row, card or record). Inherited from ASPxGridColumnDisplayTextEventArgs.

Remarks

The ASPxGridView enables you to implement your own logic to group rows, by handling the ASPxGridView.CustomColumnGroup event. In this instance, it may be useful to replace the default text displayed within group rows. To do this, handle the CustomGroupDisplayText event. The event arguments allow you to easily identify group rows and replace their display text.

Example

This example demonstrates how to implement custom grouping. The data is grouped by the ‘Unit Price’ column, and the column’s rows that have values between 0 and 10 are combined into a single group. Rows whose values fall between 10 and 20 are combined into another group, etc.

The ‘Unit Price’ column’s GridDataColumnSettings.SortMode property is set to ‘Custom’, and the ASPxGridView.CustomColumnGroup and ASPxGridView.CustomColumnSort events are handled identically.

Additionally, the ASPxGridView.CustomGroupDisplayText event is handled to replace the default text displayed within group rows.

The image below shows the result.

Note

Refer to the How to implement custom grouping logic for ASPxGridView columns online example to review how it works.

ASPX

<dx:ASPxGridView ID="ASPxGridView1" runat="server" AutoGenerateColumns="False" 
    DataSourceID="AccessDataSource1" KeyFieldName="ProductID" 
    OnCustomColumnGroup="ASPxGridView1_CustomColumnGroup" 
    OnCustomColumnSort="ASPxGridView1_CustomColumnSort" 
    OnCustomGroupDisplayText="ASPxGridView1_CustomGroupDisplayText">

    <GroupSummary>
        <dx:ASPxSummaryItem SummaryType="Count" />
    </GroupSummary>

    <Columns>
        <dx:GridViewDataTextColumn FieldName="ProductID" ReadOnly="True" 
            VisibleIndex="0">
            <EditFormSettings Visible="False" />
        </dx:GridViewDataTextColumn>
        <dx:GridViewDataTextColumn FieldName="ProductName" VisibleIndex="1">
        </dx:GridViewDataTextColumn>

        <dx:GridViewDataTextColumn FieldName="UnitPrice" VisibleIndex="2" 
            GroupIndex="0" SortIndex="0" SortOrder="Ascending">
            <PropertiesTextEdit DisplayFormatString="c">
            </PropertiesTextEdit>
            <Settings AllowDragDrop="False" SortMode="Custom" />
        </dx:GridViewDataTextColumn>

        <dx:GridViewDataCheckColumn FieldName="Discontinued" VisibleIndex="3">
        </dx:GridViewDataCheckColumn>
    </Columns>

    <Settings ShowGroupedColumns="True" ShowGroupPanel="True" />
</dx:ASPxGridView>

C#

protected void ASPxGridView1_CustomColumnSort(object sender, DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e){
    CompareColumnValues(e);
}

protected void ASPxGridView1_CustomColumnGroup(object sender, DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e){
    CompareColumnValues(e);
}

private void CompareColumnValues(DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs e) {
    if (e.Column.FieldName == "UnitPrice"){
        int res = 0;

        double x = Math.Floor(Convert.ToDouble(e.Value1) / 10);
        double y = Math.Floor(Convert.ToDouble(e.Value2) / 10);
        res = Comparer.Default.Compare(x, y);
        if (res < 0) res = -1;
        else if (res > 0) res = 1;
        if (res == 0 || (x > 9 && y > 9)) res = 0;

        e.Result = res;
        e.Handled = true;
    }
}

protected void ASPxGridView1_CustomGroupDisplayText(object sender, DevExpress.Web.ASPxGridView.ASPxGridViewColumnDisplayTextEventArgs e){
    if (e.Column.FieldName == "UnitPrice"){
        double d = Math.Floor(Convert.ToDouble(e.Value) / 10);
        string displayText = string.Format("{0:c} - {1:c} ", d * 10, (d + 1) * 10);
        if (d > 9) displayText = string.Format(">= {0:c} ", 100);
        e.DisplayText = displayText;
    }
}

VB.NET

Class SurroundingClass
    Protected Sub ASPxGridView1_CustomColumnSort(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs)
        CompareColumnValues(e)
    End Sub

    Protected Sub ASPxGridView1_CustomColumnGroup(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs)
        CompareColumnValues(e)
    End Sub

    Private Sub CompareColumnValues(ByVal e As DevExpress.Web.ASPxGridView.CustomColumnSortEventArgs)
        If e.Column.FieldName = "UnitPrice" Then
            Dim res As Integer = 0
            Dim x As Double = Math.Floor(Convert.ToDouble(e.Value1) / 10)
            Dim y As Double = Math.Floor(Convert.ToDouble(e.Value2) / 10)
            res = Comparer.[Default].Compare(x, y)

            If res < 0 Then
                res = -1
            ElseIf res > 0 Then
                res = 1
            End If

            If res = 0 OrElse (x > 9 AndAlso y > 9) Then res = 0
            e.Result = res
            e.Handled = True
        End If
    End Sub

    Protected Sub ASPxGridView1_CustomGroupDisplayText(ByVal sender As Object, ByVal e As DevExpress.Web.ASPxGridView.ASPxGridViewColumnDisplayTextEventArgs)
        If e.Column.FieldName = "UnitPrice" Then
            Dim d As Double = Math.Floor(Convert.ToDouble(e.Value) / 10)
            Dim displayText As String = String.Format("{0:c} - {1:c} ", d * 10, (d + 1) * 10)
            If d > 9 Then displayText = String.Format(">= {0:c} ", 100)
            e.DisplayText = displayText
        End If
    End Sub
End Class