Sub AddCustomFunction( _
   ByVal functionInfo As FunctionInfo _
) 

Dim instance As ICustomFunctionSupport
Dim functionInfo As FunctionInfo
 
instance.AddCustomFunction(functionInfo)

void AddCustomFunction( 
   FunctionInfo functionInfo
)

<Serializable()>
public class CubeFunctionInfo : FarPoint.CalcEngine.FunctionInfo 
{ 
		public override string Name { get { return "CUBE"; } } 
		public override int MinArgs { get { return 1; } } 
		public override int MaxArgs { get { return 1; } } 
		public override object Evaluate (object[] args) 
		{ 
			double num = FarPoint.CalcEngine.CalcConvert.ToDouble(args[0]); 
			return num * num * num; 
		} 
} 
FarPoint.Web.Spread.Model.ICustomFunctionSupport cfs; 
cfs = (FarPoint.Web.Spread.Model.ICustomFunctionSupport)FpSpread1.ActiveSheetView.DataModel; 
cfs.AddCustomFunction(new CubeFunctionInfo()); 
FpSpread1.ActiveSheetView.SetFormula(1, 1, "CUBE(4)");

<Serializable()> 
Public Class CubeFunctionInfo
   Inherits FarPoint.CalcEngine.FunctionInfo

   Public Overrides ReadOnly Property Name() As String
        Get
             Return "CUBE"
        End Get
   End Property

   Public Overrides ReadOnly Property MinArgs() As Integer
        Get
             Return 1
        End Get
   End Property

   Public Overrides ReadOnly Property MaxArgs() As Integer
        Get
             Return 1
        End Get
   End Property

   Public Overrides Function Evaluate(ByVal args() As Object) As Object
        Dim num As Double = FarPoint.CalcEngine.CalcConvert.ToDouble(args(0))
        Return num * num * num
   End Function
End Class

Dim cfs As FarPoint.Web.Spread.Model.ICustomFunctionSupport
cfs = FpSpread1.ActiveSheetView.DataModel
cfs.AddCustomFunction(New CubeFunctionInfo)
FpSpread1.ActiveSheetView.SetFormula(1, 1, "CUBE(4)")