Assigning multiple resources of the same type to an Appointment requires maintaining
many-to-many relationship between resources and appointments. That is why this it
is not available when binding to declarative data sources.
To use it, you need a custom provider that is capable of storing the relationships.
The XML Scheduler Provider is an example for such provider. There is also a help topic on implementing a provider that supports multi-valued resources.
You can also turn off the support selectively by setting AllowMultipleValues of
the ResourceType objects in the RadScheduler.ResourceTypes collection. The ResourceTypes
collection is available after data binding.
An example of a provider that supports multiple resource values and stores its data
in an SQL database is available here. It uses a cross-link table to store the many-to-many relationship
between appointments and resource.
RadScheduler supports assigning multiple resources of the same
type to an Appointment.
Try editing appointments in this example. It allows you to assign multiple persons
to each Appointment.
In this Demo different resources are added with different colors in the subject of the appointment so they can be easily differentiated.