P

MEPSystemType.MaterialId

Description:
Indicates the material id that should override the material for all components in the system.

public ElementId MaterialId { get; set; }

Public Property MaterialId As ElementId
Get
Set

public:
property ElementId^ MaterialId {
	ElementId^ get ();
	void set (ElementId^ value);
}

Autodesk.Revit.Exceptions.ArgumentNullException

When setting this property: A non-optional argument was null