With a previous version of your controls I created a custom appointment tooltip with a popup container control following your directions in the ticket with id T290954.
After I upgraded DevExpress to version 18.x the tooltip is not working.
How can I achieve the same functionality with 18.x version of DevExpress control?
By default, SchedulerControl shows an appointment flyout instead of a regular tooltip. To display tooltips instead of flyouts, set the SchedulerOptionsCustomization.AllowDisplayAppointmentFlyout option to false and specify the SchedulerOptionsView.ToolTipVisibility property as required.
However, I should note that flyouts are inspired by a modern version of Outlook, and you can show any control within them by handling the SchedulerControl.AppointmentFlyoutShowing event. That is why, I suggest switching to flyouts.
We have changed DayView's cells calculators in version 15.2. In the previous versions, an empty space that remained after dividing the DayView's client area into rows was shared between all time cells. Now, this space is moved to AllDayArea. The SchedulerControl elements are calculated in absolute coordinates. Use the AppointmentViewInfo.ConvertToVisualBounds method to convert the current rectangle to client coordinates:
Rectangle rect = appointmentViewInfo.Items.Bounds; rect = appointmentViewInfo.ConvertToVisualBounds(rect);