public bool IsActive { get; }

Public ReadOnly Property IsActive As Boolean
	Get

public:
property bool IsActive {
	bool get ();
}

Symbols that are not used in the document may be deactivated to conserve memory and regeneration time. When the symbol is inactive, its geometry is empty and cannot be accessed. In order to access the geometry of a symbol that is not active in the document, the symbol should first be activated by calling Activate()()()().