GanttControl.CustomDrawTaskDependency Event
Fires before a task dependency line 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
[DXCategory("Events")]
public event CustomDrawTaskDependencyEventHandler CustomDrawTaskDependency
Event Data
The CustomDrawTaskDependency event's data class is CustomDrawTaskDependencyEventArgs. The following properties provide information specific to this event:
Property | Description |
---|---|
Appearance | Provides access to appearance settings that specify the dependency line background color. |
Lines | Provides access to the collection of RectangleF structures that specify the processed dependency line. |
PredecessorNode | Gets the predecessor node. |
State | Gets the object state: normal, hot tracked, pressed, disabled, or selected. |
SuccessorNode | Gets the successor node. |
The event data class exposes the following methods:
Method | Description |
---|---|
DefaultDraw() | Draws the task dependency line. |
Example
The code below shows how to indicate a critical path in the project.
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;
}
};
The code below shows how to split a task’s bar into two bars.
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;
}
};
Note
Run the Gantt Code Examples demo to see the complete example.