Users can drag an appointment's top or bottom edge to change its start or end time. See the illustration below.
Resize Operation Availability
To disable the resize functionality, set the SchedulerControl.AllowAppointmentResize property to false. Alternatively, handle the SchedulerControl.CustomAllowAppointmentResize event to define custom logic to allow users to resize appointments.
Customize Resize Operation Behavior
The following SchedulerControl events allow you to control resize operations at all stages:
StartAppointmentResize - Occurs when the user starts to resize the appointment.
QueryContinueAppointmentResize - Raised every time the user resizes an appointment and allows you to cancel the resize operation.
ResizeAppointmentOver - Raised every time a user resizes an appointment. Allows you to handle conflicts or modify the current resize operation's behavior.
CommitAppointmentResize - Occurs when a user releases the mouse button to complete the resize operation (does not occur if the operation was cancelled). Set the Cancel parameter to true to disable default processing and implement a custom action.
CompleteAppointmentResize - Occurs when the resize operation has been completed or canceled.