TaskLink Class

Represents a Task Link object that is specific to a Gantt Chart diagram type.

Namespace: DevExpress.XtraCharts

Assembly: DevExpress.XtraCharts.v21.2.dll

NuGet Package: DevExpress.Charts

Declaration

C#

public class TaskLink :
    Relation

VB.NET

Public Class TaskLink
    Inherits Relation

Remarks

The task link is displayed as an arrowed line, connecting bars that stand for tasks or activities. It defines the relation between activities and the start and finish order.

Any data point can hold a collection of relations, i.e. TaskLink objects. A data point is called a parent point, and provides access to a TaskLink collection by its SeriesPoint.Relations property. A point that the parent point is linked with is called a child point.

There are different types of links between parent and child points. They are defined by the TaskLinkType enumeration. The link type for the TaskLink object is specified by the TaskLink.LinkType property.

Example

The following example demonstrates how to create a ChartControl with two series of the OverlappedGanttSeriesView type, and add this chart to a form at runtime. Before proceeding with this example, first create a Windows Forms Application in Visual Studio, and include all necessary assemblies to the References list of your project.

Then, add the following code to the Form.Load event handler.

C#

using System;
using System.Windows.Forms;
using DevExpress.XtraCharts;
// ...

private void Form1_Load(object sender, EventArgs e) {
    // Create a new chart.
    ChartControl overlappedGanttChart = new ChartControl();

    // Create two Gantt series.
    Series series1 = new Series("Planned", ViewType.Gantt);
    Series series2 = new Series("Completed", ViewType.Gantt);

    // Set the date-time values scale type for both series,
    // as it is qualitative, by default.
    series1.ValueScaleType = ScaleType.DateTime;
    series2.ValueScaleType = ScaleType.DateTime;

    // Add points to them.
    series1.Points.Add(new SeriesPoint("Market analysis", new DateTime[] { 
    new DateTime(2006, 8, 16), new DateTime(2006, 8, 23) }));
    series1.Points.Add(new SeriesPoint("Feature planning", new DateTime[] { 
    new DateTime(2006, 8, 23), new DateTime(2006, 8, 26) }));
    series1.Points.Add(new SeriesPoint("Implementation", new DateTime[] { 
    new DateTime(2006, 8, 26), new DateTime(2006, 9, 26) }));
    series1.Points.Add(new SeriesPoint("Testing & bug fixing", new DateTime[] { 
    new DateTime(2006, 9, 26), new DateTime(2006, 10, 10) }));

    series2.Points.Add(new SeriesPoint("Market analysis", new DateTime[] { 
    new DateTime(2006, 8, 16), new DateTime(2006, 8, 23) }));
    series2.Points.Add(new SeriesPoint("Feature planning", new DateTime[] { 
    new DateTime(2006, 8, 23), new DateTime(2006, 8, 26) }));
    series2.Points.Add(new SeriesPoint("Implementation", new DateTime[] { 
    new DateTime(2006, 8, 26), new DateTime(2006, 9, 10) }));

    // Add both series to the chart.
    overlappedGanttChart.Series.AddRange(new Series[] { series1, series2 });

    // Access the view-type-specific options of the series.
    ((GanttSeriesView)series1.View).BarWidth = 0.6;
    ((GanttSeriesView)series2.View).BarWidth = 0.3;

    // Access the type-specific options of the diagram.
    GanttDiagram myDiagram = (GanttDiagram)overlappedGanttChart.Diagram;

    myDiagram.AxisY.Interlaced = true;
    myDiagram.AxisY.GridSpacing = 10;
    myDiagram.AxisY.Label.Angle = -30;
    myDiagram.AxisY.DateTimeOptions.Format = DateTimeFormat.MonthAndDay;

    // Add task links for the first Gantt series.
    ((GanttSeriesView)series1.View).LinkOptions.ArrowHeight = 7;
    ((GanttSeriesView)series1.View).LinkOptions.ArrowWidth = 11;
    for (int i = 1; i < series1.Points.Count; i++) {
        series1.Points[i].Relations.Add(series1.Points[i - 1]);
    }

    // Add a progress line.
    ConstantLine progress =
    new ConstantLine("Current progress", new DateTime(2006, 9, 10));
    progress.ShowInLegend = false;
    progress.Title.Alignment = ConstantLineTitleAlignment.Far;
    myDiagram.AxisY.ConstantLines.Add(progress);

    // Adjust the legend.
    overlappedGanttChart.Legend.AlignmentHorizontal = 
        LegendAlignmentHorizontal.Right;

    // Add a title to the chart (if necessary).
    overlappedGanttChart.Titles.Add(new ChartTitle());
    overlappedGanttChart.Titles[0].Text = "R&amp;D Schedule";

    // Add the chart to the form.
    overlappedGanttChart.Dock = DockStyle.Fill;
    this.Controls.Add(overlappedGanttChart);
 }

VB.NET

Imports System
Imports System.Windows.Forms
Imports DevExpress.XtraCharts
' ...

Private Sub Form1_Load(ByVal sender As Object, _ 
ByVal e As EventArgs) Handles MyBase.Load
    ' Create a new chart.
    Dim overlappedGanttChart As New ChartControl()

    ' Create two Gantt series.
    Dim series1 As New Series("Planned", ViewType.Gantt)
    Dim series2 As New Series("Completed", ViewType.Gantt)

    ' Set the date-time values scale type for both series,
    ' as it is qualitative, by default.
    series1.ValueScaleType = ScaleType.DateTime
    series2.ValueScaleType = ScaleType.DateTime

    ' Add points to them.
    series1.Points.Add(New SeriesPoint("Market analysis", _ 
New DateTime() { New DateTime(2006, 8, 16), New DateTime(2006, 8, 23) }))
    series1.Points.Add(New SeriesPoint("Feature planning", _ 
New DateTime() { New DateTime(2006, 8, 23), New DateTime(2006, 8, 26) }))
    series1.Points.Add(New SeriesPoint("Implementation", _ 
New DateTime() { New DateTime(2006, 8, 26), New DateTime(2006, 9, 26) }))
    series1.Points.Add(New SeriesPoint("Testing & bug fixing", _ 
New DateTime() { New DateTime(2006, 9, 26), New DateTime(2006, 10, 10) }))

    series2.Points.Add(New SeriesPoint("Market analysis", _ 
New DateTime() { New DateTime(2006, 8, 16), New DateTime(2006, 8, 23) }))
    series2.Points.Add(New SeriesPoint("Feature planning", _ 
New DateTime() { New DateTime(2006, 8, 23), New DateTime(2006, 8, 26) }))
    series2.Points.Add(New SeriesPoint("Implementation", _ 
New DateTime() { New DateTime(2006, 8, 26), New DateTime(2006, 9, 10) }))

    ' Add both series to the chart.
    overlappedGanttChart.Series.AddRange(New Series() { series1, series2 })

    ' Access the view-type-specific options of the series.
    CType(series1.View, GanttSeriesView).BarWidth = 0.6
    CType(series2.View, GanttSeriesView).BarWidth = 0.3

    ' Access the type-specific options of the diagram.
    Dim myDiagram As GanttDiagram = CType(overlappedGanttChart.Diagram, GanttDiagram)

    myDiagram.AxisY.Interlaced = True
    myDiagram.AxisY.GridSpacing = 10
    myDiagram.AxisY.Label.Angle = -30
    myDiagram.AxisY.DateTimeOptions.Format = DateTimeFormat.MonthAndDay

    ' Add task links for the first Gantt series.
    CType(series1.View, GanttSeriesView).LinkOptions.ArrowHeight = 7
    CType(series1.View, GanttSeriesView).LinkOptions.ArrowWidth = 11
    For i As Integer = 1 To series1.Points.Count - 1
    series1.Points(i).Relations.Add(series1.Points(i - 1))
    Next i

    ' Add a progress line.
    Dim progress As New ConstantLine("Current progress", New DateTime(2006, 9, 10))
    progress.ShowInLegend = False
    progress.Title.Alignment = ConstantLineTitleAlignment.Far
    myDiagram.AxisY.ConstantLines.Add(progress)

    ' Adjust the legend.
    overlappedGanttChart.Legend.AlignmentHorizontal = LegendAlignmentHorizontal.Right

    ' Add a title to the chart (if necessary).
    overlappedGanttChart.Titles.Add(New ChartTitle())
    overlappedGanttChart.Titles(0).Text = "R&D Schedule"

    ' Add the chart to the form.
    overlappedGanttChart.Dock = DockStyle.Fill
    Me.Controls.Add(overlappedGanttChart)
End Sub

Inheritance

Object

ChartElement

Relation

TaskLink