The Top-Bottom (FormatConditionTopBottom) format conditions allow you to highlight a specific number of topmost/bottommost values. This example shows how to apply conditional formatting to the specified number of top/bottom values. The number of values can be specified as an absolute value or a percentage of all values.

The Average format condition (FormatConditionAverage) is used to highlight values above or below an average value.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/how-to-apply-conditional-formatting-to-grid-cells-using-the-top-bottom-average-conditions-t259930.

Form1.cs
Form1.vb

using DevExpress.DashboardCommon;
using System.Drawing;

namespace Grid_TopAverageCondition {
    public partial class Form1 : DevExpress.XtraEditors.XtraForm {
        public Form1() {
            InitializeComponent();
            Dashboard dashboard = new Dashboard(); dashboard.LoadFromXml(@"..\..\Data\Dashboard.xml");
            dashboardViewer1.Dashboard = dashboard;
            GridDashboardItem grid = (GridDashboardItem)dashboard.Items["gridDashboardItem1"];
            GridDimensionColumn salesPerson = (GridDimensionColumn)grid.Columns[0];
            GridMeasureColumn extendedPrice = (GridMeasureColumn)grid.Columns[1];

            GridItemFormatRule topRule = new GridItemFormatRule(extendedPrice, salesPerson);
            FormatConditionTopBottom topCondition = new FormatConditionTopBottom();
            topCondition.TopBottom = DashboardFormatConditionTopBottomType.Top;
            topCondition.RankType = DashboardFormatConditionValueType.Number;
            topCondition.Rank = 3;
            topCondition.StyleSettings = new IconSettings(FormatConditionIconType.IndicatorGreenCheck);
            topRule.Condition = topCondition;

            GridItemFormatRule bottomRule = new GridItemFormatRule(extendedPrice, salesPerson);
            FormatConditionTopBottom bottomCondition = new FormatConditionTopBottom();
            bottomCondition.TopBottom = DashboardFormatConditionTopBottomType.Bottom;
            bottomCondition.RankType = DashboardFormatConditionValueType.Percent;
            bottomCondition.Rank = 40;
            bottomCondition.StyleSettings = new IconSettings(FormatConditionIconType.IndicatorRedFlag);
            bottomRule.Condition = bottomCondition;

            GridItemFormatRule aboveAverageRule = new GridItemFormatRule(extendedPrice);
            FormatConditionAverage aboveAverageCondition = new FormatConditionAverage();
            aboveAverageCondition.AverageType = DashboardFormatConditionAboveBelowType.Above;
            aboveAverageCondition.StyleSettings = 
                new AppearanceSettings(Color.Green, FontStyle.Underline);
            aboveAverageRule.Condition = aboveAverageCondition;

            GridItemFormatRule belowAverageRule = new GridItemFormatRule(extendedPrice);
            FormatConditionAverage belowAverageCondition = new FormatConditionAverage();
            belowAverageCondition.AverageType = DashboardFormatConditionAboveBelowType.Below;
            belowAverageCondition.StyleSettings = 
                new AppearanceSettings(Color.Orange, FontStyle.Underline);
            belowAverageRule.Condition = belowAverageCondition;

            grid.FormatRules.AddRange(topRule, bottomRule, aboveAverageRule, belowAverageRule);
        }
    }
}

Imports DevExpress.DashboardCommon
Imports System.Drawing

Namespace Grid_TopAverageCondition
    Partial Public Class Form1
        Inherits DevExpress.XtraEditors.XtraForm

        Public Sub New()
            InitializeComponent()
            Dim dashboard As New Dashboard()
            dashboard.LoadFromXml("..\..\Data\Dashboard.xml")
            dashboardViewer1.Dashboard = dashboard
            Dim grid As GridDashboardItem =
                CType(dashboard.Items("gridDashboardItem1"), GridDashboardItem)
            Dim salesPerson As GridDimensionColumn = CType(grid.Columns(0), GridDimensionColumn)
            Dim extendedPrice As GridMeasureColumn = CType(grid.Columns(1), GridMeasureColumn)

            Dim topRule As New GridItemFormatRule(extendedPrice, salesPerson)
            Dim topCondition As New FormatConditionTopBottom()
            topCondition.TopBottom = DashboardFormatConditionTopBottomType.Top
            topCondition.RankType = DashboardFormatConditionValueType.Number
            topCondition.Rank = 3
            topCondition.StyleSettings =
                New IconSettings(FormatConditionIconType.IndicatorGreenCheck)
            topRule.Condition = topCondition

            Dim bottomRule As New GridItemFormatRule(extendedPrice, salesPerson)
            Dim bottomCondition As New FormatConditionTopBottom()
            bottomCondition.TopBottom = DashboardFormatConditionTopBottomType.Bottom
            bottomCondition.RankType = DashboardFormatConditionValueType.Percent
            bottomCondition.Rank = 40
            bottomCondition.StyleSettings =
                New IconSettings(FormatConditionIconType.IndicatorRedFlag)
            bottomRule.Condition = bottomCondition

            Dim aboveAverageRule As New GridItemFormatRule(extendedPrice)
            Dim aboveAverageCondition As New FormatConditionAverage()
            aboveAverageCondition.AverageType = DashboardFormatConditionAboveBelowType.Above
            aboveAverageCondition.StyleSettings =
                New AppearanceSettings(Color.Green, FontStyle.Underline)
            aboveAverageRule.Condition = aboveAverageCondition

            Dim belowAverageRule As New GridItemFormatRule(extendedPrice)
            Dim belowAverageCondition As New FormatConditionAverage()
            belowAverageCondition.AverageType = DashboardFormatConditionAboveBelowType.Below
            belowAverageCondition.StyleSettings =
                New AppearanceSettings(Color.Orange, FontStyle.Underline)
            belowAverageRule.Condition = belowAverageCondition

            grid.FormatRules.AddRange(topRule, bottomRule, aboveAverageRule, belowAverageRule)
        End Sub
    End Class
End Namespace