SchedulerControl.AppointmentAdding Event

Occurs before the user has added appointments to the scheduler.

Namespace: DevExpress.Xpf.Scheduling

Assembly: DevExpress.Xpf.Scheduling.v19.2.dll

Declaration

C#

public event AppointmentAddingEventHandler AppointmentAdding

VB.NET

Public Event AppointmentAdding As AppointmentAddingEventHandler

Event Data

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

Property	Description
Appointments	Provides access to the collection of appointments the user attempts to add to the scheduler.
Cancel	Gets or sets whether the event should be canceled. Inherited from CancelRoutedEventArgs.
CanceledAppointments	Provides access to the collection of appointments that should be excluded from being added to the scheduler.
ConflictedAppointments	Returns the collection of appointments that are conflicting with the current appointments.
Handled	Gets or sets a value that indicates the present state of the event handling for a routed event as it travels the route. Inherited from RoutedEventArgs.
OriginalSource	Gets the original reporting source as determined by pure hit testing, before any possible Source adjustment by a parent class. Inherited from RoutedEventArgs.
RoutedEvent	Gets or sets the RoutedEvent associated with this RoutedEventArgs instance. Inherited from RoutedEventArgs.
Source	Gets or sets a reference to the object that raised the event. Inherited from RoutedEventArgs.

The event data class exposes the following methods:

Method	Description
InvokeEventHandler(Delegate, Object)	When overridden in a derived class, provides a way to invoke event handlers in a type-specific way, which can increase efficiency over the base implementation. Inherited from RoutedEventArgs.
OnSetSource(Object)	When overridden in a derived class, provides a notification callback entry point whenever the value of the Source property of an instance changes. Inherited from RoutedEventArgs.

Remarks

To prevent specific appointments from being added to the scheduler, add them to the CanceledAppointments collection.

The code snippet below demonstrates how to implement custom validation:

C#

 AppointmentAdding += (d, e) => { 
    foreach(var apt in e.Appointments) { //each appointment which is about to be added
        bool res = Validate(apt); //is validated by a custom method 
        if(!res) //if the validation fails 
            e.CanceledEditAppointments.Add(apt); //this appointment is not added to the scheduler
    } 
}

VB.NET

AddHandler AppointmentAdding, Sub(d, e)
    For Each apt In e.Appointments 'each appointment which is about to be added
        Dim res As Boolean = Validate(apt) 'is validated by a custom method
        If Not res Then 'if the validation fails
            e.CanceledEditAppointments.Add(apt) 'this appointment is not added to the scheduler
        End If
    Next apt
End Sub

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the AppointmentAdding event.

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-validate-appointment-items-on-adding-or-editing-them-in-SchedulerControl/CS/DXSample/ValidationClasses/SchedulerValidationService.cs#L54

    scheduler.AppointmentEditing += Scheduler_AppointmentEditing;
    scheduler.AppointmentAdding += Scheduler_AppointmentAdding;
}

VB.NET

How-to-validate-appointment-items-on-adding-or-editing-them-in-SchedulerControl/VB/DXSample/ValidationClasses/SchedulerValidationService.vb#L60

    AddHandler scheduler.AppointmentEditing, AddressOf Scheduler_AppointmentEditing
    AddHandler scheduler.AppointmentAdding, AddressOf Scheduler_AppointmentAdding
End Sub