The DevExpress ASP.NET Diagram (ASPxDiagram) control allows you to restrict edit operations. To prohibit an operation, set the corresponding Allow{Operation} property to false.
In this demo, the RequestEditOperation event handler implements a custom logic to determine whether an operation is allowed. The updateUI event parameter indicates whether the event is raised by user actions or UI update. If a user tries to perform a prohibited action, an error message is displayed.