Imports System
Imports System.Reflection
Imports System.Reflection.Emit

Class DemoMethodBuilder

   Public Shared Sub AddMethodDynamically(ByVal myTypeBld As TypeBuilder, _
                                          ByVal mthdName As String, _
                                          ByVal mthdParams() As Type, _
                                          ByVal returnType As Type, _
                                          ByVal mthdAction As String)

      Dim myMthdBld As MethodBuilder = myTypeBld.DefineMethod(mthdName, _
                                       MethodAttributes.Public Or MethodAttributes.Static, _
                                       returnType, _
                                       mthdParams)

      Dim ILout As ILGenerator = myMthdBld.GetILGenerator()

      Dim numParams As Integer = mthdParams.Length

      Dim x As Byte
      For x = 0 To numParams - 1
         ILout.Emit(OpCodes.Ldarg_S, x)
      Next x

      If numParams > 1 Then
         Dim y As Integer
         For y = 0 To (numParams - 1) - 1
            Select Case mthdAction
               Case "A"
                  ILout.Emit(OpCodes.Add)
               Case "M"
                  ILout.Emit(OpCodes.Mul)
               Case Else
                  ILout.Emit(OpCodes.Add)
            End Select
         Next y
      End If
      ILout.Emit(OpCodes.Ret)
   End Sub 


   Public Shared Sub Main()

      Dim myDomain As AppDomain = AppDomain.CurrentDomain
      Dim asmName As New AssemblyName()
      asmName.Name = "MyDynamicAsm"

      Dim myAsmBuilder As AssemblyBuilder = myDomain.DefineDynamicAssembly(asmName, _
                                            AssemblyBuilderAccess.RunAndSave)

      Dim myModule As ModuleBuilder = myAsmBuilder.DefineDynamicModule("MyDynamicAsm", _
                                                                       "MyDynamicAsm.dll")

      Dim myTypeBld As TypeBuilder = myModule.DefineType("MyDynamicType", TypeAttributes.Public)

      ' Get info from the user to build the method dynamically.
      Console.WriteLine("Let's build a simple method dynamically!")
      Console.WriteLine("Please enter a few numbers, separated by spaces.")
      Dim inputNums As String = Console.ReadLine()
      Console.Write("Do you want to [A]dd (default) or [M]ultiply these numbers? ")
      Dim myMthdAction As String = Console.ReadLine().ToUpper()
      Console.Write("Lastly, what do you want to name your new dynamic method? ")
      Dim myMthdName As String = Console.ReadLine()

      ' Process inputNums into an array and create a corresponding Type array 
      Dim index As Integer = 0
      Dim inputNumsList As String() = inputNums.Split()

      Dim myMthdParams(inputNumsList.Length - 1) As Type
      Dim inputValsList(inputNumsList.Length - 1) As Object


      Dim inputNum As String
      For Each inputNum In  inputNumsList
         inputValsList(index) = CType(Convert.ToInt32(inputNum), Object)
         myMthdParams(index) = GetType(Integer)
         index += 1
      Next inputNum

      ' Now, call the method building method with the parameters, passing the 
      ' TypeBuilder by reference.
      AddMethodDynamically(myTypeBld, myMthdName, myMthdParams, GetType(Integer), myMthdAction)

      Dim myType As Type = myTypeBld.CreateType()

      Dim description as String 
      If myMthdAction = "M" Then
         description = "multiplying"
      Else
         description = "adding"
      End If

      Console.WriteLine("---")
      Console.WriteLine("The result of {0} the values is: {1}", _
                         description, _
                         myType.InvokeMember(myMthdName, _
                                             BindingFlags.InvokeMethod _
                                               Or BindingFlags.Public _
                                               Or BindingFlags.Static, _
                                             Nothing, _
                                             Nothing, _
                                             inputValsList)) 
      Console.WriteLine("---")

      ' If you are interested in seeing the MSIL generated dynamically for the method
      ' your program generated, change to the directory where you ran the compiled
      ' code sample and type "ildasm MyDynamicAsm.dll" at the prompt. When the list
      ' of manifest contents appears, click on "MyDynamicType" and then on the name of
      ' of the method you provided during execution.

      myAsmBuilder.Save("MyDynamicAsm.dll") 

      Dim myMthdInfo As MethodInfo = myType.GetMethod(myMthdName)
      Console.WriteLine("Your Dynamic Method: {0};", myMthdInfo.ToString())
   End Sub 
End Class 

using System;
using System.Reflection;
using System.Reflection.Emit;

class DemoMethodBuilder 
{
    public static void AddMethodDynamically (TypeBuilder myTypeBld,
                                             string mthdName,
                                             Type[] mthdParams, 
                                             Type returnType,
                                             string mthdAction) 
    {

        MethodBuilder myMthdBld = myTypeBld.DefineMethod(
                                             mthdName,
                                             MethodAttributes.Public |
                                             MethodAttributes.Static,
                                             returnType,
                                             mthdParams);        

        ILGenerator ILout = myMthdBld.GetILGenerator();

        int numParams = mthdParams.Length;

        for (byte x=0; x < numParams; x++) 
        {
            ILout.Emit(OpCodes.Ldarg_S, x);
        }

        if (numParams > 1) 
        {
            for (int y=0; y<(numParams-1); y++) 
            {
                switch (mthdAction) 
                {
                    case "A": ILout.Emit(OpCodes.Add);
                              break;
                    case "M": ILout.Emit(OpCodes.Mul);
                              break;
                    default: ILout.Emit(OpCodes.Add);
                              break;
                }
            }
        }
        ILout.Emit(OpCodes.Ret);
    }

    public static void Main()
    {
        AppDomain myDomain = AppDomain.CurrentDomain;
        AssemblyName asmName = new AssemblyName();
        asmName.Name = "MyDynamicAsm";

        AssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(
                                       asmName, 
                                       AssemblyBuilderAccess.RunAndSave);

        ModuleBuilder myModule = myAsmBuilder.DefineDynamicModule("MyDynamicAsm",
                                                                  "MyDynamicAsm.dll");

        TypeBuilder myTypeBld = myModule.DefineType("MyDynamicType",
                                                    TypeAttributes.Public);           

        // Get info from the user to build the method dynamically.
        Console.WriteLine("Let's build a simple method dynamically!");
        Console.WriteLine("Please enter a few numbers, separated by spaces.");
        string inputNums = Console.ReadLine();
        Console.Write("Do you want to [A]dd (default) or [M]ultiply these numbers? ");
        string myMthdAction = Console.ReadLine().ToUpper();
        Console.Write("Lastly, what do you want to name your new dynamic method? ");
        string myMthdName = Console.ReadLine();

        // Process inputNums into an array and create a corresponding Type array 
        int index = 0;
        string[] inputNumsList = inputNums.Split();

        Type[] myMthdParams = new Type[inputNumsList.Length];
        object[] inputValsList = new object[inputNumsList.Length];


        foreach (string inputNum in inputNumsList) 
        {
            inputValsList[index] = (object)Convert.ToInt32(inputNum);
                myMthdParams[index] = typeof(int);
                index++;
        } 

        // Now, call the method building method with the parameters, passing the 
        // TypeBuilder by reference.
        AddMethodDynamically(myTypeBld,
                             myMthdName,
                             myMthdParams,
                             typeof(int),        
                             myMthdAction);

        Type myType = myTypeBld.CreateType();

        Console.WriteLine("---");
        Console.WriteLine("The result of {0} the inputted values is: {1}",
                          ((myMthdAction == "M") ? "multiplying" : "adding"),
                          myType.InvokeMember(myMthdName,
                          BindingFlags.InvokeMethod | BindingFlags.Public |
                          BindingFlags.Static,
                          null,
                          null,
                          inputValsList));
        Console.WriteLine("---");

        // Let's take a look at the method we created.
        // If you are interested in seeing the MSIL generated dynamically for the method
        // your program generated, change to the directory where you ran the compiled
        // code sample and type "ildasm MyDynamicAsm.dll" at the prompt. When the list
        // of manifest contents appears, click on "MyDynamicType" and then on the name of
        // of the method you provided during execution.

        myAsmBuilder.Save("MyDynamicAsm.dll");

        MethodInfo myMthdInfo = myType.GetMethod(myMthdName);
        Console.WriteLine("Your Dynamic Method: {0};", myMthdInfo.ToString());    
    }
}

using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;

void AddMethodDynamically( TypeBuilder^ myTypeBld, 
                           String^ mthdName, 
                           array<Type^>^ mthdParams, 
                           Type^ returnType, 
                           String^ mthdAction )
{
   MethodBuilder^ myMthdBld = myTypeBld->DefineMethod( mthdName, static_cast<MethodAttributes>(MethodAttributes::Public | MethodAttributes::Static), returnType, mthdParams );
   ILGenerator^ ILOut = myMthdBld->GetILGenerator();
   int numParams = mthdParams->Length;
   for ( Byte x = 0; x < numParams; x++ )
   {
      ILOut->Emit( OpCodes::Ldarg_S, x );

   }
   if ( numParams > 1 )
   {
      for ( int y = 0; y < (numParams - 1); y++ )
      {
         if ( mthdAction->Equals( "A" ) )
                  ILOut->Emit( OpCodes::Add );
         else
         if ( mthdAction->Equals( "M" ) )
                  ILOut->Emit( OpCodes::Mul );
         else
                  ILOut->Emit( OpCodes::Add );

      }
   }

   ILOut->Emit( OpCodes::Ret );
};

void main()
{
   AppDomain^ myDomain = AppDomain::CurrentDomain;
   AssemblyName^ asmName = gcnew AssemblyName;
   asmName->Name = "MyDynamicAsm";
   AssemblyBuilder^ myAsmBuilder = myDomain->DefineDynamicAssembly( asmName, 
                                                                    AssemblyBuilderAccess::RunAndSave );
   ModuleBuilder^ myModule = myAsmBuilder->DefineDynamicModule( "MyDynamicAsm", 
                                                                "MyDynamicAsm.dll" );
   TypeBuilder^ myTypeBld = myModule->DefineType( "MyDynamicType", 
                                                  TypeAttributes::Public );

   // Get info from the user to build the method dynamically.
   Console::WriteLine( "Let's build a simple method dynamically!" );
   Console::WriteLine( "Please enter a few numbers, separated by spaces." );
   String^ inputNums = Console::ReadLine();
   Console::Write( "Do you want to [A]dd (default) or [M]ultiply these numbers? " );
   String^ myMthdAction = Console::ReadLine()->ToUpper();
   Console::Write( "Lastly, what do you want to name your new dynamic method? " );
   String^ myMthdName = Console::ReadLine();

   // Process inputNums into an array and create a corresponding Type array
   int index = 0;
   array<String^>^inputNumsList = inputNums->Split();
   array<Type^>^myMthdParams = gcnew array<Type^>(inputNumsList->Length);
   array<Object^>^inputValsList = gcnew array<Object^>(inputNumsList->Length);
   for each (String^ inputNum in inputNumsList)
   {
      inputValsList[ index ] = Convert::ToInt32( inputNum );
      myMthdParams[ index ] = int::typeid;
      index++;
   }


   // Now, call the method building method with the parameters, passing the
   // TypeBuilder by reference.
   AddMethodDynamically( myTypeBld, 
                         myMthdName, 
                         myMthdParams, 
                         int::typeid, 
                         myMthdAction );
   Type^ myType = myTypeBld->CreateType();

   Console::WriteLine( "---" );
   Console::WriteLine( "The result of {0} the inputted values is: {1}", 
                       ((myMthdAction->Equals( "M" )) ? "multiplying" : "adding"), 
                       myType->InvokeMember( myMthdName, 
                                             BindingFlags::InvokeMethod | BindingFlags::Public | BindingFlags::Static, 
                       nullptr, 
                       nullptr, 
                       inputValsList ) );
   Console::WriteLine( "---" );

   // Let's take a look at the method we created.
   // If you are interested in seeing the MSIL generated dynamically for the method
   // your program generated, change to the directory where you ran the compiled
   // code sample and type "ildasm MyDynamicAsm.dll" at the prompt. When the list
   // of manifest contents appears, click on "MyDynamicType" and then on the name of
   // of the method you provided during execution.

   myAsmBuilder->Save( "MyDynamicAsm.dll" );

   MethodInfo^ myMthdInfo = myType->GetMethod( myMthdName );
   Console::WriteLine( "Your Dynamic Method: {0};", myMthdInfo );
}