aspnet-9222-components-pivot-grid-examples-data-shaping-how-to-locate-a-column-row-header-by-its-columns-rows-summary-values.md
The following example demonstrates how to handle the CustomFieldValueCells event to locate a specific column/row header identified by its column's/row's summary values.
In this example, a predicate is used to locate a column that contains only zero summary values. The column header is obtained by the event parameter's FindCell method, and then removed via the Remove method.
using System;
using System.Globalization;
using System.Web.UI;
using DevExpress.Web.ASPxPivotGrid;
using DevExpress.XtraPivotGrid;
namespace ASPxPivotGrid_FindCells {
public partial class _Default : Page {
protected void Page_Load(object sender, EventArgs e) {
if (!IsCallback && !IsPostBack) {
PivotHelper.FillPivot(pivotGrid);
}
pivotGrid.DataSource = PivotHelper.GetDataTable();
}
// Handles the CustomFieldValueCells event to remove columns with
// zero summary values.
protected void pivotGrid_CustomFieldValueCells(object sender,
PivotCustomFieldValueCellsEventArgs e) {
if (pivotGrid.DataSource == null) return;
if (radioButtonList.SelectedIndex == 0) return;
// Obtains the first encountered column header whose column
// matches the specified condition, represented by a predicate.
FieldValueCell cell = e.FindCell(true, new Predicate<object[]>(
// Defines the predicate returning true for columns
// that contain only zero summary values.
delegate(object[] dataCellValues) {
foreach (object value in dataCellValues) {
if (!object.Equals((decimal)0, value))
return false;
}
return true;
}));
// If any column header matches the condition, this column is removed.
if (cell != null) e.Remove(cell);
}
protected void pivotGrid_FieldValueDisplayText(object sender,
PivotFieldDisplayTextEventArgs e) {
if (e.Field == pivotGrid.Fields[PivotHelper.Month]) {
e.DisplayText = CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName((int)e.Value);
}
}
}
}
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs"
Inherits="ASPxPivotGrid_FindCells._Default" %>
<%@ Register Assembly="DevExpress.Web.ASPxPivotGrid.v10.2, Version=10.2.3.0,
Culture=neutral, PublicKeyToken=b88d1754d700e49a"
Namespace="DevExpress.Web.ASPxPivotGrid"
TagPrefix="dx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:RadioButtonList ID="radioButtonList" runat="server"
AutoPostBack="true" CellSpacing="10" >
<asp:ListItem Selected="True">Default Layout</asp:ListItem>
<asp:ListItem>Remove Columns with Zero Summary Values</asp:ListItem>
</asp:RadioButtonList>
<div>
<dx:ASPxPivotGrid ID="pivotGrid" runat="server" Width="500px"
OnFieldValueDisplayText="pivotGrid_FieldValueDisplayText"
OnCustomFieldValueCells="pivotGrid_CustomFieldValueCells"
OptionsCustomization-AllowFilter="false"
OptionsCustomization-AllowDrag="false">
</dx:ASPxPivotGrid>
</div>
</form>
</body>
</html>
<%@ Page Language="vb" AutoEventWireup="true" CodeBehind="Default.aspx.vb"
Inherits="ASPxPivotGrid_FindCells._Default" %>
<%@ Register Assembly="DevExpress.Web.ASPxPivotGrid.v10.2, Version=10.2.3.0,
Culture=neutral, PublicKeyToken=b88d1754d700e49a"
Namespace="DevExpress.Web.ASPxPivotGrid"
TagPrefix="dx" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:RadioButtonList ID="radioButtonList" runat="server"
AutoPostBack="true" CellSpacing="10" >
<asp:ListItem Selected="True">Default Layout</asp:ListItem>
<asp:ListItem>Remove Columns with Zero Summary Values</asp:ListItem>
</asp:RadioButtonList>
<div>
<dx:ASPxPivotGrid ID="pivotGrid" runat="server" Width="500px"
OnFieldValueDisplayText="pivotGrid_FieldValueDisplayText"
OnCustomFieldValueCells="pivotGrid_CustomFieldValueCells"
OptionsCustomization-AllowFilter="false"
OptionsCustomization-AllowDrag="false">
</dx:ASPxPivotGrid>
</div>
</form>
</body>
</html>
Imports Microsoft.VisualBasic
Imports System
Imports System.Globalization
Imports System.Web.UI
Imports DevExpress.Web.ASPxPivotGrid
Imports DevExpress.XtraPivotGrid
Namespace ASPxPivotGrid_FindCells
Partial Public Class _Default
Inherits Page
Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
If (Not IsCallback) AndAlso (Not IsPostBack) Then
PivotHelper.FillPivot(pivotGrid)
End If
pivotGrid.DataSource = PivotHelper.GetDataTable()
End Sub
' Handles the CustomFieldValueCells event to remove columns with
' zero summary values.
Protected Sub pivotGrid_CustomFieldValueCells(ByVal sender As Object, _
ByVal e As PivotCustomFieldValueCellsEventArgs)
If pivotGrid.DataSource Is Nothing Then
Return
End If
If radioButtonList.SelectedIndex = 0 Then
Return
End If
' Obtains the first encountered column header whose column
' matches the specified condition, represented by a predicate.
Dim cell As FieldValueCell = _
e.FindCell(True, New Predicate(Of Object())(AddressOf AnonymousMethod1))
' If any column header matches the condition, this column is removed.
If cell IsNot Nothing Then
e.Remove(cell)
End If
End Sub
' Defines the predicate returning true for columns
' that contain only zero summary values.
Private Function AnonymousMethod1(ByVal dataCellValues() As Object) As Boolean
For Each value As Object In dataCellValues
If (Not Object.Equals(CDec(0), value)) Then
Return False
End If
Next value
Return True
End Function
Protected Sub pivotGrid_FieldValueDisplayText(ByVal sender As Object, _
ByVal e As PivotFieldDisplayTextEventArgs)
If e.Field Is pivotGrid.Fields(PivotHelper.Month) Then
e.DisplayText = _
CultureInfo.CurrentCulture.DateTimeFormat.GetMonthName(CInt(Fix(e.Value)))
End If
End Sub
End Class
End Namespace