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TdxGanttControlTaskStartLinkEvent Type

Performs a set of actions before a user drags and drops a dependency from one task to another with the mouse.

#Declaration

Delphi
TdxGanttControlTaskStartLinkEvent = procedure(Sender: TObject; ATask: TdxGanttControlTask; var AAllow: Boolean) of object;

#Parameters

Name Type Description
Sender TObject

The Chart View that raised the event.

ATask TdxGanttControlTask

The predecessor task.

AAllow Boolean

If True, a user can move the mouse pointer from the selected task to another task (while holding the left mouse button) to link them. If False, the operation is prohibited.

#Remarks

You can open the Features Demo and modify its code. Handle the OnTaskStartLink event and use the following code snippet to prevent a user from linking a summary task to any task:

procedure TFeaturesDemoMainForm.GanttControlViewChartTaskStartLink(Sender: TObject;
  ATask: TdxGanttControlTask; var AAllow: Boolean);
begin
    AAllow := not ATask.Summary;
end;
See Also