By default, the control automatically generates an unique identifier for each link. You can use the ID property to define your id for the link. The control fires the CreateLink event when the user adds at runtime a link between two elements. The AllowLinkObjects property specifies the keys combination to let the user links two elements on the surface, the ElementFrom property specifies the element where the link starts, where the ElementTo property specifies ending element of the link. Prior to CreateLink event the control fires the AddLink event that indicates that the link has been added to the Links collection. The AllowLink event occurs when user links two elements to specify whether the link is allowed.