devexpress-examples / winforms-scheduler-enforce-task-dependencies-gantt-view

Enforce task dependencies in the Gantt view of the WinForms Scheduler Control.

WinForms Scheduler - Enforce task dependencies in the Gantt view

This example handles the AllowAppointmentConflicts event to implement restrictions on appointment editing (appointments linked with a dependency should follow dependency rules).

If two appointments are linked with a Finish-to-Start dependency, the Finish value of the parent appointment should always be less than or equal to the Start value of the dependent appointment. The example uses GetDependenciesByDependentId and GetDependenciesByParentId methods to obtain dependency collections.

private void schedulerControl1_AllowAppointmentConflicts(object sender, AppointmentConflictEventArgs e) {
    e.Conflicts.Clear();
    AppointmentDependencyBaseCollection depCollectionDep = 
        schedulerDataStorage1.AppointmentDependencies.Items.GetDependenciesByDependentId(e.Appointment.Id);
    if (depCollectionDep.Count > 0) {
        if (CheckForInvalidDependenciesAsDependent(depCollectionDep, e.AppointmentClone))
            e.Conflicts.Add(e.AppointmentClone);
    }
    AppointmentDependencyBaseCollection depCollectionPar = 
        schedulerDataStorage1.AppointmentDependencies.Items.GetDependenciesByParentId(e.Appointment.Id);
    if (depCollectionPar.Count > 0) {
        if (CheckForInvalidDependenciesAsParent(depCollectionPar, e.AppointmentClone))
            e.Conflicts.Add(e.AppointmentClone);
    }
}