GanttControl.CustomDrawTask Event

Fires before a task in the chart area is displayed. Provides access to a drawing surface and allows you to draw the task manually.

Namespace: DevExpress.XtraGantt

Assembly: DevExpress.XtraGantt.v20.1.dll

NuGet Package: DevExpress.Win.Gantt

Declaration

C#

[DXCategory("Events")]
public event CustomDrawTaskEventHandler CustomDrawTask

VB.NET

<DXCategory("Events")>
Public Event CustomDrawTask As CustomDrawTaskEventHandler

Event Data

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

Property	Description
Appearance	Provides access to the task’s appearance settings.
Duration	Gets the task duration.
FinishDate	Gets the task finish date.
Info	Provides access to view information about the task.
Node	Gets the processed node.
Progress	Gets the task progress.
StartDate	Gets the task start date.
State	Gets the object state: normal, hot tracked, pressed, disabled, or selected.

The event data class exposes the following methods:

Method	Description
DrawBaseline()	Draws the baseline.
DrawBaseline(RectangleF)	Draws the baseline in the specified bounds.
DrawInsideText()	Draws the text inside the bar.
DrawLeftLinkPoint()
DrawLeftText()	Draws the text to the left of the bar.
DrawLeftText(RectangleF)	Draws the text to the left of the bar within the specified bounds.
DrawRightLinkPoint()
DrawRightText()	Draws the text to the right of the bar.
DrawRightText(RectangleF)	Draws the text to the left of the bar within the specified bounds.
DrawShape()	Draws the task shape: bar, summary bar, or milestone.
DrawShape(DateTime, DateTime)	Draws the task shape (bar, summary bar, or milestone) with an interruption.
DrawShape(RectangleF, Single)	Draws the task shape: bar, summary bar, or milestone.
GetPosition(DateTime)

Example

The code below shows how to indicate a critical path in the project.

C#

HashSet<int> criticalPathIds = new HashSet<int> { 1, 2, 3, 6, 7, 8, 10, 11, 13 };
ganttControl.CustomDrawTask += (sender, e) => {
    int taskId = Convert.ToInt32(e.Node.GetValue("Id"));
    if(criticalPathIds.Contains(taskId)) {
        e.Appearance.BackColor = DXSkinColors.FillColors.Danger;
        e.Appearance.ProgressColor = DXSkinColors.FillColors.Danger;
    }
};
ganttControl.CustomDrawTaskDependency += (sender, e) => {
    int predecessorId = Convert.ToInt32(e.PredecessorNode.GetValue("Id"));
    int successorId = Convert.ToInt32(e.SuccessorNode.GetValue("Id"));
    if(criticalPathIds.Contains(predecessorId) && criticalPathIds.Contains(successorId)) {
        e.Appearance.BackColor = DXSkinColors.FillColors.Danger;
    }
};

VB.NET

Dim criticalPathIds As New HashSet(Of Integer)() From {1, 2, 3, 6, 7, 8, 10, 11, 13}
AddHandler ganttControl.CustomDrawTask, Sub(sender, e)
    Dim taskId As Integer = Convert.ToInt32(e.Node.GetValue("Id"))
    If criticalPathIds.Contains(taskId) Then
        e.Appearance.BackColor = DXSkinColors.FillColors.Danger
        e.Appearance.ProgressColor = DXSkinColors.FillColors.Danger
    End If
End Sub
AddHandler ganttControl.CustomDrawTaskDependency, Sub(sender, e)
    Dim predecessorId As Integer = Convert.ToInt32(e.PredecessorNode.GetValue("Id"))
    Dim successorId As Integer = Convert.ToInt32(e.SuccessorNode.GetValue("Id"))
    If criticalPathIds.Contains(predecessorId) AndAlso criticalPathIds.Contains(successorId) Then
        e.Appearance.BackColor = DXSkinColors.FillColors.Danger
    End If
End Sub

The code below shows how to split a task’s bar into two bars.

C#

ganttControl.CustomDrawTask += (sender, e) => {
    if(e.Node.Id == 3) {
        e.Appearance.BackColor = DXSkinColors.FillColors.Danger;
        e.Appearance.ProgressColor = DXSkinColors.FillColors.Danger;
        TimeSpan offset = TimeSpan.FromHours(2);
        e.DrawShape(e.Info.StartDate + offset, e.Info.FinishDate - offset);
        e.DrawRightText();
        e.Handled = true;
    }
};

VB.NET

AddHandler ganttControl.CustomDrawTask, Sub(sender, e)
    If e.Node.Id = 3 Then
        e.Appearance.BackColor = DXSkinColors.FillColors.Danger
        e.Appearance.ProgressColor = DXSkinColors.FillColors.Danger
        Dim offset As TimeSpan = TimeSpan.FromHours(2)
        e.DrawShape(e.Info.StartDate + offset, e.Info.FinishDate - offset)
        e.DrawRightText()
        e.Handled = True
    End If
End Sub

Note

Run the Gantt Code Examples demo to see the complete example.