SchedulerOptionsCustomization.AllowAppointmentConflicts Property

Gets or sets whether a user is allowed to share the schedule time between two or more appointments.

Namespace: DevExpress.XtraScheduler

Assembly: DevExpress.XtraScheduler.v19.2.Core.dll

Declaration

C#

[DefaultValue(AppointmentConflictsMode.Allowed)]
public AppointmentConflictsMode AllowAppointmentConflicts { get; set; }

VB.NET

<DefaultValue(AppointmentConflictsMode.Allowed)>
Public Property AllowAppointmentConflicts As AppointmentConflictsMode

Property Value

Type	Default	Description
AppointmentConflictsMode	**Allowed**	An AppointmentConflictsMode enumeration value specifying whether the time interval of two or more appointments can intersect or not, if these appointments belong to the same resource(s).

Available values:

Name	Description
Allowed	Appointments conflicts are allowed. This means that appointment intervals can intersect for the same resource (or for at least for one of the resources to which they belong, if resources are shared).
Forbidden	Appointments conflicts are forbidden. This means that appointment intervals can’t intersect each other for the same resource (or for at least for one of the resources to which they belong, if resources are shared).
Custom	Whether the conflicts are resolved or not is determined manually in the corresponding event handler.

Property Paths

You can access this nested property as listed below:

Library	Object Type	Path to AllowAppointmentConflicts
WinForms Controls	SchedulerControl	.OptionsCustomization.AllowAppointmentConflicts
ASP.NET Controls and MVC Extensions	ASPxScheduler	.OptionsCustomization.AllowAppointmentConflicts
	MVCxScheduler	.OptionsCustomization.AllowAppointmentConflicts
	SchedulerSettings	.OptionsCustomization.AllowAppointmentConflicts
ASP.NET Bootstrap Controls	BootstrapScheduler	.OptionsCustomization.AllowAppointmentConflicts
eXpressApp Framework	SchedulerListEditorBase	.OptionsCustomization.AllowAppointmentConflicts
	ASPxSchedulerListEditor	.OptionsCustomization.AllowAppointmentConflicts
	SchedulerListEditor	.OptionsCustomization.AllowAppointmentConflicts

Remarks

By default, end users can share the schedule time between two or more appointments. Use the AllowAppointmentConflicts property to control the availability of such functionality to end-users.

If this property is set to AppointmentConflictsMode.Allowed, the time interval of two or more appointments can intersect and sharing the schedule time between the appointments is allowed. Set the AllowAppointmentConflicts property to AppointmentConflictsMode.Forbidden to prevent scheduling (or rescheduling) of two or more appointments for the same time.

Note

If the AllowAppointmentConflicts property is set to AppointmentConflictsMode.Custom, then whether an end-user is allowed to share the schedule time between two or more appointments or not is decided in the SchedulerControl.AllowAppointmentConflicts event handler.

Change the Conflict Message

When a conflict occurs, the Scheduler shows a message box that notifies users about this conflict. The code below illustrates how to change this message box text.

C#

public Form1() {
    InitializeComponent();
    SchedulerResLocalizer.Active = new CustomSchedulerResLocalizer();
}

public class CustomSchedulerResLocalizer : SchedulerResLocalizer {
    public override string GetLocalizedString(SchedulerStringId id) {
        if(id == SchedulerStringId.Msg_Conflict)
            return "_YOUR_CUSTOM_MESSAGE_TEXT_";
        else 
            return base.GetLocalizedString(id);
    }    
}

VB.NET

Public Sub New()
    InitializeComponent()
    SchedulerResLocalizer.Active = New CustomSchedulerResLocalizer()
 End Sub

Public Class CustomSchedulerResLocalizer
    Inherits SchedulerResLocalizer

    Public Overrides Function GetLocalizedString(ByVal id As SchedulerStringId) As String
        If id Is SchedulerStringId.Msg_Conflict Then
            Return "_YOUR_CUSTOM_MESSAGE_TEXT_"
        Else
            Return MyBase.GetLocalizedString(id)
        End If
    End Function
End Class

Example

The following code snippet illustrates handling of the SchedulerControl.AllowAppointmentConflicts event for conflict resolution. When an appointment is modified or created, and the SchedulerOptionsCustomization.AllowAppointmentConflicts property is set to AppointmentConflictsMode.Custom, the AllowAppointmentConflicts event occurs. The code in the event handler checks whether the time interval of the modified appointment intersects with other appointments, including recurrent series and exceptions. If such an appointment is found, it is added to the AppointmentConflictEventArgs.Conflicts collection. If the collection has at least one element, a conflict occurs and the Scheduler cancels changes.

Note

A complete sample project is available at https://github.com/DevExpress-Examples/winforms-schedulercontrol-api-t224044

AppointmentConflicts.cs

    // Concurrent appointments with the same resource are not allowed.
    scheduler.OptionsCustomization.AllowAppointmentConflicts = AppointmentConflictsMode.Custom;
    scheduler.AllowAppointmentConflicts += Scheduler_AllowAppointmentConflicts;

    scheduler.Storage.Appointments.Clear();
    scheduler.GroupType = SchedulerGroupType.Resource;
    Appointment apt1 = scheduler.Storage.Appointments.CreateAppointment(AppointmentType.Normal, DateTime.Now, DateTime.Now.AddHours(2));
    apt1.ResourceId = scheduler.Storage.Resources[0].Id;
    scheduler.Storage.Appointments.Add(apt1);
    Appointment apt2 = scheduler.Storage.Appointments.CreateAppointment(AppointmentType.Normal, DateTime.Now, DateTime.Now.AddHours(2));
    apt2.ResourceId = scheduler.Storage.Resources[1].Id;
    scheduler.Storage.Appointments.Add(apt2);
static void Scheduler_AllowAppointmentConflicts(object sender, AppointmentConflictEventArgs e) {
    e.Conflicts.Clear();
    FillConflictedAppointmentsCollection(e.Conflicts, e.Interval, ((SchedulerControl)sender).Storage.Appointments.Items, e.AppointmentClone);
}
static void FillConflictedAppointmentsCollection(AppointmentBaseCollection conflicts, TimeInterval interval,
    AppointmentBaseCollection collection, Appointment currApt) {
    for (int i = 0; i < collection.Count; i++) {
        Appointment apt = collection[i];
        if (new TimeInterval(apt.Start, apt.End).IntersectsWith(interval) & !(apt.Start == interval.End || apt.End == interval.Start)) {
            if (apt.ResourceId == currApt.ResourceId) {
                conflicts.Add(apt);
            }
        }
        if (apt.Type == AppointmentType.Pattern) {
            FillConflictedAppointmentsCollection(conflicts, interval, apt.GetExceptions(), currApt);
        }
    }
}

AppointmentConflicts.vb

    ' Concurrent appointments with the same resource are not allowed.
    scheduler.OptionsCustomization.AllowAppointmentConflicts = AppointmentConflictsMode.Custom
    AddHandler scheduler.AllowAppointmentConflicts, AddressOf Scheduler_AllowAppointmentConflicts

    scheduler.Storage.Appointments.Clear()
    scheduler.GroupType = SchedulerGroupType.Resource
    Dim apt1 As Appointment = scheduler.Storage.Appointments.CreateAppointment(AppointmentType.Normal, Date.Now, Date.Now.AddHours(2))
    apt1.ResourceId = scheduler.Storage.Resources(0).Id
    scheduler.Storage.Appointments.Add(apt1)
    Dim apt2 As Appointment = scheduler.Storage.Appointments.CreateAppointment(AppointmentType.Normal, Date.Now, Date.Now.AddHours(2))
    apt2.ResourceId = scheduler.Storage.Resources(1).Id
    scheduler.Storage.Appointments.Add(apt2)
Private Shared Sub Scheduler_AllowAppointmentConflicts(ByVal sender As Object, ByVal e As AppointmentConflictEventArgs)
    e.Conflicts.Clear()
    FillConflictedAppointmentsCollection(e.Conflicts, e.Interval, DirectCast(sender, SchedulerControl).Storage.Appointments.Items, e.AppointmentClone)
End Sub
Private Shared Sub FillConflictedAppointmentsCollection(ByVal conflicts As AppointmentBaseCollection, ByVal interval As TimeInterval, ByVal collection As AppointmentBaseCollection, ByVal currApt As Appointment)
    For i As Integer = 0 To collection.Count - 1
        Dim apt As Appointment = collection(i)
        If (New TimeInterval(apt.Start, apt.End)).IntersectsWith(interval) And Not(apt.Start = interval.End OrElse apt.End = interval.Start) Then
            If apt.ResourceId Is currApt.ResourceId Then
                conflicts.Add(apt)
            End If
        End If
        If apt.Type = AppointmentType.Pattern Then
            FillConflictedAppointmentsCollection(conflicts, interval, apt.GetExceptions(), currApt)
        End If
    Next i
End Sub

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the AllowAppointmentConflicts property.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

how-to-enforce-task-dependencies-in-the-gantt-view-e3579/CS/GanttRestrictions/Form1.cs#L27

this.schedulerControl1.OptionsCustomization.AllowAppointmentConflicts = AppointmentConflictsMode.Custom;
this.schedulerControl1.AllowAppointmentConflicts+=new AppointmentConflictEventHandler(schedulerControl1_AllowAppointmentConflicts);

winforms-schedulercontrol-api-t224044/CS/SchedulerAPISample/CodeExamples/AppointmentConflicts.cs#L16

// Concurrent appointments with the same resource are not allowed.
scheduler.OptionsCustomization.AllowAppointmentConflicts = AppointmentConflictsMode.Custom;
scheduler.AllowAppointmentConflicts += Scheduler_AllowAppointmentConflicts;

VB.NET

how-to-enforce-task-dependencies-in-the-gantt-view-e3579/VB/GanttRestrictions/Form1.vb#L25

Me.schedulerControl1.OptionsCustomization.AllowAppointmentConflicts = AppointmentConflictsMode.Custom
AddHandler schedulerControl1.AllowAppointmentConflicts, AddressOf schedulerControl1_AllowAppointmentConflicts

winforms-schedulercontrol-api-t224044/VB/SchedulerAPISample/CodeExamples/AppointmentConflicts.vb#L14

' Concurrent appointments with the same resource are not allowed.
scheduler.OptionsCustomization.AllowAppointmentConflicts = AppointmentConflictsMode.Custom
AddHandler scheduler.AllowAppointmentConflicts, AddressOf Scheduler_AllowAppointmentConflicts