dashboard-404406-winforms-dashboard-winforms-designer-create-dashboards-in-the-winforms-designer-dashboard-item-settings-chart-trend-indicators.md
The Dashboard Designer allows you to display predefined trend indicators in Chart dashboard items. You can also create and register custom indicators.
Trend indicators are statistical tools used to analyze data and identify patterns or relationships between variables.
The following indicator types are available:
Trend LineDisplays the general direction of associated points. It is often used to identify existing data trends and can help forecast future trends.Regression LineVisualizes data using a mathematical formula that minimizes the distance between the line itself and associated data points. It is used to model the relationship between two variables and can be used to make predictions about one variable based on the value of another.Custom Indicator Allows you to implement your own custom indicator type.
Click the Trend Indicators button in the Analysis group of the Data Ribbon page. This command invokes the Trend Indicators dialog:
The dialog contains the following buttons:
Add Creates a new indicator.Remove Removes the selected indicator.OK Saves changes and closes the dialog.Apply Saves changes and keeps the dialog open.Cancel Closes the dialog and discards unsaved changes.
New indicators are generated with default settings:
You can change the following settings before displaying an indicator in a Chart dashboard item.
NameThe name of the trend indicator within the indicators collection.TypeThe indicator type: Trend Line, Regression Line, or a Custom Type.ValueThe measure data item that is used to calculate the trend indicator.Value LevelThe value that specifies which series point value should be used to calculate the indicator.Display In LegendSpecifies whether to display the trend indicator in the legend.Legend TextThe text that identifies the trend indicator within the legend.Dash StyleThe dash style used to paint the line.ThicknessThe thickness of the indicator line.Color The color for the trend indicator.VisibleSpecifies whether to display the trend indicator.
You can create a trend indicator in code as follows:
Create a ChartRegressionLine or ChartTrendLine object and specify its settings.
Add the created object to the ChartDashboardItem.Indicators collection to display the configured indicator in the UI.
The following example shows how to create a trend line at runtime:
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using DevExpress.DashboardCommon;
namespace WinForm {
public partial class FormDesigner : Form {
public FormDesigner() {
InitializeComponent();
var dashboard = new Dashboard1();
ChartDashboardItem chartItem = dashboard.Items.First(x => x.ComponentName == "chartDashboardItem1") as ChartDashboardItem;
ChartTrendLine trendline = new ChartTrendLine();
SimpleSeries simpleSeries = chartItem.Panes[0].Series[0] as SimpleSeries;
if (simpleSeries != null) {
trendLine.Value = simpleSeries.Value.UniqueId;
}
trendline.Name = "Trend Indicator";
trendline.ValueLevel = DevExpress.XtraCharts.ValueLevel.Value;
trendline.LegendText = "Sales Trend";
trendline.ShowInLegend = true;
trendline.Color = Color.DarkGreen;
chartItem.Indicators.Add(trendline);
dashboardDesigner.Dashboard = dashboard;
dashboardDesigner.CreateRibbon();
dashboardDesigner.CreateCustomItemBars();
}
}
}
Imports System.Drawing
Imports System.Linq
Imports System.Windows.Forms
Imports DevExpress.DashboardCommon
Namespace WinForm
Partial Public Class FormDesigner
Inherits Form
Public Sub New()
InitializeComponent()
Dim dashboard = New Dashboard1()
Dim chartItem As ChartDashboardItem = TryCast(dashboard.Items.First(Function(x) x.ComponentName = "chartDashboardItem1"), ChartDashboardItem)
Dim trendline As New ChartTrendLine()
Dim simpleSeries As SimpleSeries = TryCast(chartItem.Panes(0).Series(0), SimpleSeries)
If simpleSeries IsNot Nothing Then
trendLine.Value = simpleSeries.Value.UniqueId
End If
trendline.Name = "Trend Indicator"
trendline.ValueLevel = DevExpress.XtraCharts.ValueLevel.Value
trendline.LegendText = "Sales Trend"
trendline.ShowInLegend = True
trendline.Color = Color.DarkGreen
chartItem.Indicators.Add(trendline)
dashboardDesigner.Dashboard = dashboard
dashboardDesigner.CreateRibbon()
dashboardDesigner.CreateCustomItemBars()
End Sub
End Class
End Namespace
You can also edit the newly created indicator in the Trend Indicators dialog:
Follow the instructions below to create a custom “Moving Average” indicator:
Create a ChartCustomIndicator descendant (the MovingIndicator class in this example). MovingIndicator accepts a collection of data points, evaluates the values, and returns the resulting points. These points are used to draw the indicator.
Register the MovingIndicator type in IndicatorFactory to make this type available as the indicator type in the Trend Indicators editor.
Call the Register method in your application before you save and load a dashboard to serialize and deserialize the indicator within the dashboard XML.
Create an instance of MovingIndicator and specify indicator settings.
This property is required to display the indicator in the Chart dashboard item when you launch the application:
ValueSpecifies the measure data item that is used to calculate the trend indicator.
If you do not specify the following properties, their default values are used:
NameSpecifies the name of the trend indicator within the indicators collection.ValueLevelGets or sets the value that specifies which series point value should be used to calculate the indicator.ShowInLegendSpecifies whether to display the trend indicator in the legend.LegendTextSpecifies the text that identifies the trend indicator within the legend.ThicknessSpecifies the thickness of the indicator line.ColorSpecifies the trend indicator’s color.DashStyleSpecifies the dash style used to paint the line.VisibleSpecifies whether to display the trend indicator.
Add MovingIndicator to the chart indicators collection to display the configured indicator in the UI.
The following code snippet illustrates the steps above:
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using DevExpress.DashboardCommon;
using DevExpress.DashboardCommon.ViewerData;
namespace WinForm {
public partial class FormDesigner : Form {
public FormDesigner() {
try {
IndicatorFactory.Register<MovingIndicator>("Moving average");
} catch(Exception e) {
MessageBox.Show(e.Message);
}
InitializeComponent();
var dashboard = new Dashboard1();
ChartDashboardItem chartItem = dashboard.Items.First(x => x.ComponentName == "chartDashboardItem1") as ChartDashboardItem;
MovingIndicator trendLine = new MovingIndicator() {
Name = "MovingLine1",
Value = "DataItem1",
ValueLevel = DevExpress.XtraCharts.ValueLevel.Value,
Color = Color.Orange,
LegendText = "Moving Average"
};
chartItem.Indicators.Add(trendLine);
dashboardDesigner.Dashboard = dashboard;
dashboardDesigner.CreateRibbon();
dashboardDesigner.CreateCustomItemBars();
}
}
public class MovingIndicator : ChartCustomIndicator {
protected override Dictionary<AxisPoint, object> Calculate(Dictionary<AxisPoint, decimal?> values) {
var items = new Dictionary<AxisPoint, object>(values.Count);
var sum = decimal.Zero;
var count = 0;
foreach(KeyValuePair<AxisPoint, decimal?> point in values) {
if(count == 0) {
items.Add(point.Key, null);
} else {
items.Add(point.Key, sum / count);
}
sum += point.Value ?? 0;
count++;
}
return items;
}
}
}
Imports System
Imports System.Collections.Generic
Imports System.Drawing
Imports System.Linq
Imports System.Windows.Forms
Imports DevExpress.DashboardCommon
Imports DevExpress.DashboardCommon.ViewerData
Namespace WinForm
Partial Public Class FormDesigner
Inherits Form
Public Sub New()
Try
IndicatorFactory.Register(Of MovingIndicator)("Moving average")
Catch e As Exception
MessageBox.Show(e.Message)
End Try
InitializeComponent()
Dim dashboard = New Dashboard1()
Dim chartItem As ChartDashboardItem = TryCast(dashboard.Items.First(Function(x) x.ComponentName = "chartDashboardItem1"), ChartDashboardItem)
Dim trendLine As New MovingIndicator() With {
.Name = "MovingLine1",
.Value = "DataItem1",
.ValueLevel = DevExpress.XtraCharts.ValueLevel.Value,
.Color = Color.Orange,
.LegendText = "Moving Average"
}
chartItem.Indicators.Add(trendLine)
dashboardDesigner.Dashboard = dashboard
dashboardDesigner.CreateRibbon()
dashboardDesigner.CreateCustomItemBars()
End Sub
End Class
Public Class MovingIndicator
Inherits ChartCustomIndicator
Protected Overrides Function Calculate(ByVal values As Dictionary(Of AxisPoint, Decimal?)) As Dictionary(Of AxisPoint, Object)
Dim items = New Dictionary(Of AxisPoint, Object)(values.Count)
Dim sum = Decimal.Zero
Dim count = 0
For Each point As KeyValuePair(Of AxisPoint, Decimal?) In values
If count = 0 Then
items.Add(point.Key, Nothing)
Else
items.Add(point.Key, sum / count)
End If
sum += If(point.Value, 0)
count += 1
Next point
Return items
End Function
End Class
End Namespace
The following image illustrates the result: