Public Overridable Function TryBinaryOperation ( _
    binder As BinaryOperationBinder, _
    arg As Object, _
    <OutAttribute> ByRef result As Object _
) As Boolean

Dim instance As DynamicObject
Dim binder As BinaryOperationBinder
Dim arg As Object
Dim result As Object
Dim returnValue As Boolean

returnValue = instance.TryBinaryOperation(binder, _
    arg, result)

public virtual bool TryBinaryOperation(
    BinaryOperationBinder binder,
    Object arg,
    out Object result
)

public:
virtual bool TryBinaryOperation(
    BinaryOperationBinder^ binder, 
    Object^ arg, 
    [OutAttribute] Object^% result
)

abstract TryBinaryOperation : 
        binder:BinaryOperationBinder * 
        arg:Object * 
        result:Object byref -> bool 
override TryBinaryOperation : 
        binder:BinaryOperationBinder * 
        arg:Object * 
        result:Object byref -> bool 

using System;
using System.Collections.Generic;
using System.Dynamic;
using System.Linq.Expressions;

// The class derived from DynamicObject.
public class DynamicNumber : DynamicObject
{
    // The inner dictionary to store field names and values.
    Dictionary<string, object> dictionary
        = new Dictionary<string, object>();

    // Get the property value.
    public override bool TryGetMember(
        GetMemberBinder binder, out object result)
    {
        return dictionary.TryGetValue(binder.Name, out result);
    }

    // Set the property value.
    public override bool TrySetMember(
        SetMemberBinder binder, object value)
    {
        dictionary[binder.Name] = value;
        return true;
    }

    // Perform the binary operation. 
    public override bool TryBinaryOperation(
        BinaryOperationBinder binder, object arg, out object result)
    {
        // The Textual property contains the textual representaion 
        // of two numbers, in addition to the name 
        // of the binary operation.
        string resultTextual =
            dictionary["Textual"].ToString() + " "
            + binder.Operation + " " +
            ((DynamicNumber)arg).dictionary["Textual"].ToString();

        int resultNumeric;

        // Checking what type of operation is being performed.
        switch (binder.Operation)
        {
            // Proccessing mathematical addition (a + b).
            case ExpressionType.Add:
                resultNumeric =
                    (int)dictionary["Numeric"] +  
                    (int)((DynamicNumber)arg).dictionary["Numeric"];
                break;

            // Processing mathematical substraction (a - b).
            case ExpressionType.Subtract:
                resultNumeric =
                    (int)dictionary["Numeric"] - 
                    (int)((DynamicNumber)arg).dictionary["Numeric"];
                break;

            // In case of any other binary operation,
            // print out the type of operation and return false,
            // which means that the language should determine 
            // what to do.
            // (Usually the language just throws an exception.)
            default:
                Console.WriteLine(
                    binder.Operation + 
                    ": This binary operation is not implemented");
                result = null;
                return false;
        }

        dynamic finalResult = new DynamicNumber();
        finalResult.Textual = resultTextual;
        finalResult.Numeric = resultNumeric;
        result = finalResult;
        return true;
    }
}

class Program
{
    static void Main(string[] args)
    {
        // Creating the first dynamic number.
        dynamic firstNumber = new DynamicNumber();

        // Creating properties and setting their values
        // for the first dynamic number.
        // The TrySetMember method is called.
        firstNumber.Textual = "One";
        firstNumber.Numeric = 1;

        // Printing out properties. The TryGetMember method is called.
        Console.WriteLine(
            firstNumber.Textual + " " + firstNumber.Numeric);

        // Creating the second dynamic number.
        dynamic secondNumber = new DynamicNumber();       
        secondNumber.Textual = "Two";
        secondNumber.Numeric = 2;
        Console.WriteLine(
            secondNumber.Textual + " " + secondNumber.Numeric);
       

        dynamic resultNumber = new DynamicNumber();

        // Adding two numbers. The TryBinaryOperation is called.
        resultNumber = firstNumber + secondNumber;

        Console.WriteLine(
            resultNumber.Textual + " " + resultNumber.Numeric);

        // Subtracting two numbers. TryBinaryOperation is called.
        resultNumber = firstNumber - secondNumber;

        Console.WriteLine(
            resultNumber.Textual + " " + resultNumber.Numeric);

        // The following statement produces a run-time exception
        // because the multiplication operation is not implemented.
        // resultNumber = firstNumber * secondNumber;
    }
}

// This code example produces the following output:

// One 1
// Two 2
// One Add Two 3
// One Subtract Two -1

Imports System.Linq.Expressions
Imports System.Dynamic

' The class derived from DynamicObject.
Public Class DynamicNumber
    Inherits DynamicObject

    ' The inner dictionary to store field names and values.
    Dim dictionary As New Dictionary(Of String, Object)

    ' Get the property value.
    Public Overrides Function TryGetMember(
        ByVal binder As System.Dynamic.GetMemberBinder, 
        ByRef result As Object) As Boolean

        Return dictionary.TryGetValue(binder.Name, result)

    End Function

    ' Set the property value.
    Public Overrides Function TrySetMember(
        ByVal binder As System.Dynamic.SetMemberBinder, 
        ByVal value As Object) As Boolean

        dictionary(binder.Name) = value
        Return True

    End Function

    ' Perform the binary operation. 
    Public Overrides Function TryBinaryOperation(
        ByVal binder As System.Dynamic.BinaryOperationBinder, 
        ByVal arg As Object, ByRef result As Object) As Boolean

        ' The Textual property contains the textual representaion 
        ' of two numbers, in addition to the name of the binary operation.
        Dim resultTextual As String =
            dictionary("Textual") & " " &
            binder.Operation.ToString() & " " &
        CType(arg, DynamicNumber).dictionary("Textual")

        Dim resultNumeric As Integer

        ' Checking what type of operation is being performed.
        Select Case binder.Operation
            ' Proccessing mathematical addition (a + b).
            Case ExpressionType.Add
                resultNumeric =
                CInt(dictionary("Numeric")) +
                CInt((CType(arg, DynamicNumber)).dictionary("Numeric"))

                ' Processing mathematical substraction (a - b).
            Case ExpressionType.Subtract
                resultNumeric =
                CInt(dictionary("Numeric")) -
                CInt((CType(arg, DynamicNumber)).dictionary("Numeric"))
                
            Case Else
                ' In case of any other binary operation,
                ' print out the type of operation and return false,
                ' which means that the language should determine 
                ' what to do.
                ' (Usually the language just throws an exception.)
                Console.WriteLine(
                    binder.Operation.ToString() &
                    ": This binary operation is not implemented")
                result = Nothing
                Return False
        End Select

        Dim finalResult As Object = New DynamicNumber()
        finalResult.Textual = resultTextual
        finalResult.Numeric = resultNumeric
        result = finalResult
        Return True       
    End Function
End Class


Module Module1
    Sub Main()
        ' Creating the first dynamic number.
        Dim firstNumber As Object = New DynamicNumber()

        ' Creating properties and setting their values
        ' for the first dynamic number. 
        ' The TrySetMember method is called.
        firstNumber.Textual = "One"
        firstNumber.Numeric = 1

        ' Printing out properties. The TryGetMember method is called.
        Console.WriteLine(
            firstNumber.Textual & " " & firstNumber.Numeric)

        ' Creating the second dynamic number.
        Dim secondNumber As Object = New DynamicNumber()
        secondNumber.Textual = "Two"
        secondNumber.Numeric = 2
        Console.WriteLine(
            secondNumber.Textual & " " & secondNumber.Numeric)

        Dim resultNumber As Object = New DynamicNumber()

        ' Adding two numbers. TryBinaryOperation is called.
        resultNumber = firstNumber + secondNumber
        Console.WriteLine(
            resultNumber.Textual & " " & resultNumber.Numeric)

        ' Subtracting two numbers. TryBinaryOperation is called.
        resultNumber = firstNumber - secondNumber
        Console.WriteLine(
            resultNumber.Textual & " " & resultNumber.Numeric)

        ' The following statement produces a run-time exception
        ' because the multiplication operation is not implemented.
        ' resultNumber = firstNumber * secondNumber
    End Sub
End Module

' This code example produces the following output:

' One 1
' Two 2
' One Add Two 3
' One Subtract Two -1