TypeBuilder Klas

Definitie

public ref class TypeBuilder sealed : Type, System::Runtime::InteropServices::_TypeBuilder

public ref class TypeBuilder sealed : System::Reflection::TypeInfo, System::Runtime::InteropServices::_TypeBuilder

public ref class TypeBuilder sealed : Type

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
public sealed class TypeBuilder : Type, System.Runtime.InteropServices._TypeBuilder

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class TypeBuilder : Type, System.Runtime.InteropServices._TypeBuilder

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Runtime.InteropServices.ComVisible(true)]
public sealed class TypeBuilder : System.Reflection.TypeInfo, System.Runtime.InteropServices._TypeBuilder

public sealed class TypeBuilder : Type

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)>]
type TypeBuilder = class
    inherit Type
    interface _TypeBuilder

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type TypeBuilder = class
    inherit Type
    interface _TypeBuilder

[<System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type TypeBuilder = class
    inherit TypeInfo
    interface _TypeBuilder

type TypeBuilder = class
    inherit Type

Public NotInheritable Class TypeBuilder
Inherits Type
Implements _TypeBuilder

Public NotInheritable Class TypeBuilder
Inherits TypeInfo
Implements _TypeBuilder

Public NotInheritable Class TypeBuilder
Inherits Type

Overname

Object

MemberInfo

Type

TypeBuilder

Overname

Object

MemberInfo

Type

TypeInfo

TypeBuilder

Kenmerken

ClassInterfaceAttribute ComVisibleAttribute

Implementeringen

_TypeBuilder

Voorbeelden

In het volgende codevoorbeeld ziet u hoe u een dynamische assembly definieert en gebruikt. De voorbeeldassembly bevat één type, MyDynamicTypedat een privéveld bevat, een eigenschap die het privéveld ophaalt en instelt, constructors die het privéveld initialiseren en een methode waarmee een door de gebruiker opgegeven getal wordt vermenigvuldigd met de waarde van het privéveld en het resultaat wordt geretourneerd.

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

class DemoAssemblyBuilder
{
    public static void Main()
    {
        // This code creates an assembly that contains one type,
        // named "MyDynamicType", that has a private field, a property
        // that gets and sets the private field, constructors that
        // initialize the private field, and a method that multiplies
        // a user-supplied number by the private field value and returns
        // the result. In C# the type might look like this:
        /*
        public class MyDynamicType
        {
            private int m_number;

            public MyDynamicType() : this(42) {}
            public MyDynamicType(int initNumber)
            {
                m_number = initNumber;
            }

            public int Number
            {
                get { return m_number; }
                set { m_number = value; }
            }

            public int MyMethod(int multiplier)
            {
                return m_number * multiplier;
            }
        }
        */

        var aName = new AssemblyName("DynamicAssemblyExample");
        AssemblyBuilder ab =
            AssemblyBuilder.DefineDynamicAssembly(
                aName,
                AssemblyBuilderAccess.Run);

        // The module name is usually the same as the assembly name.
        ModuleBuilder mb = ab.DefineDynamicModule(aName.Name ?? "DynamicAssemblyExample");

        TypeBuilder tb = mb.DefineType(
            "MyDynamicType",
             TypeAttributes.Public);

        // Add a private field of type int (Int32).
        FieldBuilder fbNumber = tb.DefineField(
            "m_number",
            typeof(int),
            FieldAttributes.Private);

        // Define a constructor that takes an integer argument and
        // stores it in the private field.
        Type[] parameterTypes = { typeof(int) };
        ConstructorBuilder ctor1 = tb.DefineConstructor(
            MethodAttributes.Public,
            CallingConventions.Standard,
            parameterTypes);

        ILGenerator ctor1IL = ctor1.GetILGenerator();
        // For a constructor, argument zero is a reference to the new
        // instance. Push it on the stack before calling the base
        // class constructor. Specify the default constructor of the
        // base class (System.Object) by passing an empty array of
        // types (Type.EmptyTypes) to GetConstructor.
        ctor1IL.Emit(OpCodes.Ldarg_0);
        ConstructorInfo? ci = typeof(object).GetConstructor(Type.EmptyTypes);
        ctor1IL.Emit(OpCodes.Call, ci!);
        // Push the instance on the stack before pushing the argument
        // that is to be assigned to the private field m_number.
        ctor1IL.Emit(OpCodes.Ldarg_0);
        ctor1IL.Emit(OpCodes.Ldarg_1);
        ctor1IL.Emit(OpCodes.Stfld, fbNumber);
        ctor1IL.Emit(OpCodes.Ret);

        // Define a default constructor that supplies a default value
        // for the private field. For parameter types, pass the empty
        // array of types or pass null.
        ConstructorBuilder ctor0 = tb.DefineConstructor(
            MethodAttributes.Public,
            CallingConventions.Standard,
            Type.EmptyTypes);

        ILGenerator ctor0IL = ctor0.GetILGenerator();
        // For a constructor, argument zero is a reference to the new
        // instance. Push it on the stack before pushing the default
        // value on the stack, then call constructor ctor1.
        ctor0IL.Emit(OpCodes.Ldarg_0);
        ctor0IL.Emit(OpCodes.Ldc_I4_S, 42);
        ctor0IL.Emit(OpCodes.Call, ctor1);
        ctor0IL.Emit(OpCodes.Ret);

        // Define a property named Number that gets and sets the private
        // field.
        //
        // The last argument of DefineProperty is null, because the
        // property has no parameters. (If you don't specify null, you must
        // specify an array of Type objects. For a parameterless property,
        // use the built-in array with no elements: Type.EmptyTypes)
        PropertyBuilder pbNumber = tb.DefineProperty(
            "Number",
            PropertyAttributes.HasDefault,
            typeof(int),
            null);

        // The property "set" and property "get" methods require a special
        // set of attributes.
        MethodAttributes getSetAttr = MethodAttributes.Public |
            MethodAttributes.SpecialName | MethodAttributes.HideBySig;

        // Define the "get" accessor method for Number. The method returns
        // an integer and has no arguments. (Note that null could be
        // used instead of Types.EmptyTypes)
        MethodBuilder mbNumberGetAccessor = tb.DefineMethod(
            "get_Number",
            getSetAttr,
            typeof(int),
            Type.EmptyTypes);

        ILGenerator numberGetIL = mbNumberGetAccessor.GetILGenerator();
        // For an instance property, argument zero is the instance. Load the
        // instance, then load the private field and return, leaving the
        // field value on the stack.
        numberGetIL.Emit(OpCodes.Ldarg_0);
        numberGetIL.Emit(OpCodes.Ldfld, fbNumber);
        numberGetIL.Emit(OpCodes.Ret);

        // Define the "set" accessor method for Number, which has no return
        // type and takes one argument of type int (Int32).
        MethodBuilder mbNumberSetAccessor = tb.DefineMethod(
            "set_Number",
            getSetAttr,
            null,
            new Type[] { typeof(int) });

        ILGenerator numberSetIL = mbNumberSetAccessor.GetILGenerator();
        // Load the instance and then the numeric argument, then store the
        // argument in the field.
        numberSetIL.Emit(OpCodes.Ldarg_0);
        numberSetIL.Emit(OpCodes.Ldarg_1);
        numberSetIL.Emit(OpCodes.Stfld, fbNumber);
        numberSetIL.Emit(OpCodes.Ret);

        // Last, map the "get" and "set" accessor methods to the
        // PropertyBuilder. The property is now complete.
        pbNumber.SetGetMethod(mbNumberGetAccessor);
        pbNumber.SetSetMethod(mbNumberSetAccessor);

        // Define a method that accepts an integer argument and returns
        // the product of that integer and the private field m_number. This
        // time, the array of parameter types is created on the fly.
        MethodBuilder meth = tb.DefineMethod(
            "MyMethod",
            MethodAttributes.Public,
            typeof(int),
            new Type[] { typeof(int) });

        ILGenerator methIL = meth.GetILGenerator();
        // To retrieve the private instance field, load the instance it
        // belongs to (argument zero). After loading the field, load the
        // argument one and then multiply. Return from the method with
        // the return value (the product of the two numbers) on the
        // execution stack.
        methIL.Emit(OpCodes.Ldarg_0);
        methIL.Emit(OpCodes.Ldfld, fbNumber);
        methIL.Emit(OpCodes.Ldarg_1);
        methIL.Emit(OpCodes.Mul);
        methIL.Emit(OpCodes.Ret);

        // Finish the type.
        Type? t = tb.CreateType();

        // Because AssemblyBuilderAccess includes Run, the code can be
        // executed immediately. Start by getting reflection objects for
        // the method and the property.
        MethodInfo? mi = t?.GetMethod("MyMethod");
        PropertyInfo? pi = t?.GetProperty("Number");

        // Create an instance of MyDynamicType using the default
        // constructor.
        object? o1 = null;
        if (t is not null)
            o1 = Activator.CreateInstance(t);

        // Display the value of the property, then change it to 127 and
        // display it again. Use null to indicate that the property
        // has no index.
        Console.WriteLine("o1.Number: {0}", pi?.GetValue(o1, null));
        pi?.SetValue(o1, 127, null);
        Console.WriteLine("o1.Number: {0}", pi?.GetValue(o1, null));

        // Call MyMethod, passing 22, and display the return value, 22
        // times 127. Arguments must be passed as an array, even when
        // there is only one.
        object[] arguments = { 22 };
        Console.WriteLine("o1.MyMethod(22): {0}",
            mi?.Invoke(o1, arguments));

        // Create an instance of MyDynamicType using the constructor
        // that specifies m_Number. The constructor is identified by
        // matching the types in the argument array. In this case,
        // the argument array is created on the fly. Display the
        // property value.
        object? o2 = null;
        if (t is not null)
            o2 = Activator.CreateInstance(t, new object[] { 5280 });
        Console.WriteLine("o2.Number: {0}", pi?.GetValue(o2, null));
    }
}

/* This code produces the following output:

o1.Number: 42
o1.Number: 127
o1.MyMethod(22): 2794
o2.Number: 5280
 */

Imports System.Reflection
Imports System.Reflection.Emit

Class DemoAssemblyBuilder

    Public Shared Sub Main()

        ' This code creates an assembly that contains one type,
        ' named "MyDynamicType", that has a private field, a property
        ' that gets and sets the private field, constructors that
        ' initialize the private field, and a method that multiplies
        ' a user-supplied number by the private field value and returns
        ' the result. The code might look like this in Visual Basic:
        '
        'Public Class MyDynamicType
        '    Private m_number As Integer
        '
        '    Public Sub New()
        '        Me.New(42)
        '    End Sub
        '
        '    Public Sub New(ByVal initNumber As Integer)
        '        m_number = initNumber
        '    End Sub
        '
        '    Public Property Number As Integer
        '        Get
        '            Return m_number
        '        End Get
        '        Set
        '            m_Number = Value
        '        End Set
        '    End Property
        '
        '    Public Function MyMethod(ByVal multiplier As Integer) As Integer
        '        Return m_Number * multiplier
        '    End Function
        'End Class
      
        Dim aName As New AssemblyName("DynamicAssemblyExample")
        Dim ab As AssemblyBuilder = _
            AssemblyBuilder.DefineDynamicAssembly( _
                aName, _
                AssemblyBuilderAccess.Run)

        ' The module name is usually the same as the assembly name.
        Dim mb As ModuleBuilder = ab.DefineDynamicModule( _
            aName.Name)
      
        Dim tb As TypeBuilder = _
            mb.DefineType("MyDynamicType", TypeAttributes.Public)

        ' Add a private field of type Integer (Int32).
        Dim fbNumber As FieldBuilder = tb.DefineField( _
            "m_number", _
            GetType(Integer), _
            FieldAttributes.Private)

        ' Define a constructor that takes an integer argument and 
        ' stores it in the private field. 
        Dim parameterTypes() As Type = { GetType(Integer) }
        Dim ctor1 As ConstructorBuilder = _
            tb.DefineConstructor( _
                MethodAttributes.Public, _
                CallingConventions.Standard, _
                parameterTypes)

        Dim ctor1IL As ILGenerator = ctor1.GetILGenerator()
        ' For a constructor, argument zero is a reference to the new
        ' instance. Push it on the stack before calling the base
        ' class constructor. Specify the default constructor of the 
        ' base class (System.Object) by passing an empty array of 
        ' types (Type.EmptyTypes) to GetConstructor.
        ctor1IL.Emit(OpCodes.Ldarg_0)
        ctor1IL.Emit(OpCodes.Call, _
            GetType(Object).GetConstructor(Type.EmptyTypes))
        ' Push the instance on the stack before pushing the argument
        ' that is to be assigned to the private field m_number.
        ctor1IL.Emit(OpCodes.Ldarg_0)
        ctor1IL.Emit(OpCodes.Ldarg_1)
        ctor1IL.Emit(OpCodes.Stfld, fbNumber)
        ctor1IL.Emit(OpCodes.Ret)

        ' Define a default constructor that supplies a default value
        ' for the private field. For parameter types, pass the empty
        ' array of types or pass Nothing.
        Dim ctor0 As ConstructorBuilder = tb.DefineConstructor( _
            MethodAttributes.Public, _
            CallingConventions.Standard, _
            Type.EmptyTypes)

        Dim ctor0IL As ILGenerator = ctor0.GetILGenerator()
        ' For a constructor, argument zero is a reference to the new
        ' instance. Push it on the stack before pushing the default
        ' value on the stack, then call constructor ctor1.
        ctor0IL.Emit(OpCodes.Ldarg_0)
        ctor0IL.Emit(OpCodes.Ldc_I4_S, 42)
        ctor0IL.Emit(OpCodes.Call, ctor1)
        ctor0IL.Emit(OpCodes.Ret)

        ' Define a property named Number that gets and sets the private 
        ' field.
        '
        ' The last argument of DefineProperty is Nothing, because the
        ' property has no parameters. (If you don't specify Nothing, you must
        ' specify an array of Type objects. For a parameterless property,
        ' use the built-in array with no elements: Type.EmptyTypes)
        Dim pbNumber As PropertyBuilder = tb.DefineProperty( _
            "Number", _
            PropertyAttributes.HasDefault, _
            GetType(Integer), _
            Nothing)
      
        ' The property Set and property Get methods require a special
        ' set of attributes.
        Dim getSetAttr As MethodAttributes = _
            MethodAttributes.Public Or MethodAttributes.SpecialName _
                Or MethodAttributes.HideBySig

        ' Define the "get" accessor method for Number. The method returns
        ' an integer and has no arguments. (Note that Nothing could be 
        ' used instead of Types.EmptyTypes)
        Dim mbNumberGetAccessor As MethodBuilder = tb.DefineMethod( _
            "get_Number", _
            getSetAttr, _
            GetType(Integer), _
            Type.EmptyTypes)
      
        Dim numberGetIL As ILGenerator = mbNumberGetAccessor.GetILGenerator()
        ' For an instance property, argument zero is the instance. Load the 
        ' instance, then load the private field and return, leaving the
        ' field value on the stack.
        numberGetIL.Emit(OpCodes.Ldarg_0)
        numberGetIL.Emit(OpCodes.Ldfld, fbNumber)
        numberGetIL.Emit(OpCodes.Ret)
        
        ' Define the "set" accessor method for Number, which has no return
        ' type and takes one argument of type Integer (Int32).
        Dim mbNumberSetAccessor As MethodBuilder = _
            tb.DefineMethod( _
                "set_Number", _
                getSetAttr, _
                Nothing, _
                New Type() { GetType(Integer) })
      
        Dim numberSetIL As ILGenerator = mbNumberSetAccessor.GetILGenerator()
        ' Load the instance and then the numeric argument, then store the
        ' argument in the field.
        numberSetIL.Emit(OpCodes.Ldarg_0)
        numberSetIL.Emit(OpCodes.Ldarg_1)
        numberSetIL.Emit(OpCodes.Stfld, fbNumber)
        numberSetIL.Emit(OpCodes.Ret)
      
        ' Last, map the "get" and "set" accessor methods to the 
        ' PropertyBuilder. The property is now complete. 
        pbNumber.SetGetMethod(mbNumberGetAccessor)
        pbNumber.SetSetMethod(mbNumberSetAccessor)

        ' Define a method that accepts an integer argument and returns
        ' the product of that integer and the private field m_number. This
        ' time, the array of parameter types is created on the fly.
        Dim meth As MethodBuilder = tb.DefineMethod( _
            "MyMethod", _
            MethodAttributes.Public, _
            GetType(Integer), _
            New Type() { GetType(Integer) })

        Dim methIL As ILGenerator = meth.GetILGenerator()
        ' To retrieve the private instance field, load the instance it
        ' belongs to (argument zero). After loading the field, load the 
        ' argument one and then multiply. Return from the method with 
        ' the return value (the product of the two numbers) on the 
        ' execution stack.
        methIL.Emit(OpCodes.Ldarg_0)
        methIL.Emit(OpCodes.Ldfld, fbNumber)
        methIL.Emit(OpCodes.Ldarg_1)
        methIL.Emit(OpCodes.Mul)
        methIL.Emit(OpCodes.Ret)

        ' Finish the type.
        Dim t As Type = tb.CreateType()

        ' Because AssemblyBuilderAccess includes Run, the code can be
        ' executed immediately. Start by getting reflection objects for
        ' the method and the property.
        Dim mi As MethodInfo = t.GetMethod("MyMethod")
        Dim pi As PropertyInfo = t.GetProperty("Number")
  
        ' Create an instance of MyDynamicType using the default 
        ' constructor. 
        Dim o1 As Object = Activator.CreateInstance(t)

        ' Display the value of the property, then change it to 127 and 
        ' display it again. Use Nothing to indicate that the property
        ' has no index.
        Console.WriteLine("o1.Number: {0}", pi.GetValue(o1, Nothing))
        pi.SetValue(o1, 127, Nothing)
        Console.WriteLine("o1.Number: {0}", pi.GetValue(o1, Nothing))

        ' Call MyMethod, passing 22, and display the return value, 22
        ' times 127. Arguments must be passed as an array, even when
        ' there is only one.
        Dim arguments() As Object = { 22 }
        Console.WriteLine("o1.MyMethod(22): {0}", _
            mi.Invoke(o1, arguments))

        ' Create an instance of MyDynamicType using the constructor
        ' that specifies m_Number. The constructor is identified by
        ' matching the types in the argument array. In this case, 
        ' the argument array is created on the fly. Display the 
        ' property value.
        Dim o2 As Object = Activator.CreateInstance(t, _
            New Object() { 5280 })
        Console.WriteLine("o2.Number: {0}", pi.GetValue(o2, Nothing))
      
    End Sub  
End Class

' This code produces the following output:
'
'o1.Number: 42
'o1.Number: 127
'o1.MyMethod(22): 2794
'o2.Number: 5280

In het volgende codevoorbeeld ziet u hoe u dynamisch een type bouwt met behulp van TypeBuilder.

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

class TestILGenerator
{
    public static Type DynamicDotProductGen()
    {
       Type ivType = null;
       Type[] ctorParams = new Type[] { typeof(int),
                                typeof(int),
                        typeof(int)};
    
       AppDomain myDomain = Thread.GetDomain();
       AssemblyName myAsmName = new AssemblyName();
       myAsmName.Name = "IntVectorAsm";
    
       AssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(
                      myAsmName,
                      AssemblyBuilderAccess.RunAndSave);

       ModuleBuilder IntVectorModule = myAsmBuilder.DefineDynamicModule("IntVectorModule",
                                        "Vector.dll");

       TypeBuilder ivTypeBld = IntVectorModule.DefineType("IntVector",
                                      TypeAttributes.Public);

       FieldBuilder xField = ivTypeBld.DefineField("x", typeof(int),
                                                       FieldAttributes.Private);
       FieldBuilder yField = ivTypeBld.DefineField("y", typeof(int),
                                                       FieldAttributes.Private);
       FieldBuilder zField = ivTypeBld.DefineField("z", typeof(int),
                                                       FieldAttributes.Private);

           Type objType = Type.GetType("System.Object");
           ConstructorInfo objCtor = objType.GetConstructor(new Type[0]);

       ConstructorBuilder ivCtor = ivTypeBld.DefineConstructor(
                      MethodAttributes.Public,
                      CallingConventions.Standard,
                      ctorParams);
       ILGenerator ctorIL = ivCtor.GetILGenerator();
           ctorIL.Emit(OpCodes.Ldarg_0);
           ctorIL.Emit(OpCodes.Call, objCtor);
           ctorIL.Emit(OpCodes.Ldarg_0);
           ctorIL.Emit(OpCodes.Ldarg_1);
           ctorIL.Emit(OpCodes.Stfld, xField);
           ctorIL.Emit(OpCodes.Ldarg_0);
           ctorIL.Emit(OpCodes.Ldarg_2);
           ctorIL.Emit(OpCodes.Stfld, yField);
           ctorIL.Emit(OpCodes.Ldarg_0);
           ctorIL.Emit(OpCodes.Ldarg_3);
           ctorIL.Emit(OpCodes.Stfld, zField);
       ctorIL.Emit(OpCodes.Ret);

       // This method will find the dot product of the stored vector
       // with another.

       Type[] dpParams = new Type[] { ivTypeBld };

           // Here, you create a MethodBuilder containing the
       // name, the attributes (public, static, private, and so on),
       // the return type (int, in this case), and a array of Type
       // indicating the type of each parameter. Since the sole parameter
       // is a IntVector, the very class you're creating, you will
       // pass in the TypeBuilder (which is derived from Type) instead of
       // a Type object for IntVector, avoiding an exception.

       // -- This method would be declared in C# as:
       //    public int DotProduct(IntVector aVector)

           MethodBuilder dotProductMthd = ivTypeBld.DefineMethod(
                                  "DotProduct",
                          MethodAttributes.Public,
                                          typeof(int),
                                          dpParams);

       // A ILGenerator can now be spawned, attached to the MethodBuilder.

       ILGenerator mthdIL = dotProductMthd.GetILGenerator();
    
       // Here's the body of our function, in MSIL form. We're going to find the
       // "dot product" of the current vector instance with the passed vector
       // instance. For reference purposes, the equation is:
       // (x1 * x2) + (y1 * y2) + (z1 * z2) = the dot product

       // First, you'll load the reference to the current instance "this"
       // stored in argument 0 (ldarg.0) onto the stack. Ldfld, the subsequent
       // instruction, will pop the reference off the stack and look up the
       // field "x", specified by the FieldInfo token "xField".

       mthdIL.Emit(OpCodes.Ldarg_0);
       mthdIL.Emit(OpCodes.Ldfld, xField);

       // That completed, the value stored at field "x" is now atop the stack.
       // Now, you'll do the same for the object reference we passed as a
       // parameter, stored in argument 1 (ldarg.1). After Ldfld executed,
       // you'll have the value stored in field "x" for the passed instance
       // atop the stack.

       mthdIL.Emit(OpCodes.Ldarg_1);
       mthdIL.Emit(OpCodes.Ldfld, xField);

           // There will now be two values atop the stack - the "x" value for the
       // current vector instance, and the "x" value for the passed instance.
       // You'll now multiply them, and push the result onto the evaluation stack.

       mthdIL.Emit(OpCodes.Mul_Ovf_Un);

       // Now, repeat this for the "y" fields of both vectors.

       mthdIL.Emit(OpCodes.Ldarg_0);
       mthdIL.Emit(OpCodes.Ldfld, yField);
       mthdIL.Emit(OpCodes.Ldarg_1);
       mthdIL.Emit(OpCodes.Ldfld, yField);
       mthdIL.Emit(OpCodes.Mul_Ovf_Un);

       // At this time, the results of both multiplications should be atop
       // the stack. You'll now add them and push the result onto the stack.

       mthdIL.Emit(OpCodes.Add_Ovf_Un);

       // Multiply both "z" field and push the result onto the stack.
       mthdIL.Emit(OpCodes.Ldarg_0);
       mthdIL.Emit(OpCodes.Ldfld, zField);
       mthdIL.Emit(OpCodes.Ldarg_1);
       mthdIL.Emit(OpCodes.Ldfld, zField);
       mthdIL.Emit(OpCodes.Mul_Ovf_Un);

       // Finally, add the result of multiplying the "z" fields with the
       // result of the earlier addition, and push the result - the dot product -
       // onto the stack.
       mthdIL.Emit(OpCodes.Add_Ovf_Un);

       // The "ret" opcode will pop the last value from the stack and return it
       // to the calling method. You're all done!

       mthdIL.Emit(OpCodes.Ret);

       ivType = ivTypeBld.CreateType();

       return ivType;
    }

    public static void Main() {
    
       Type IVType = null;
           object aVector1 = null;
           object aVector2 = null;
       Type[] aVtypes = new Type[] {typeof(int), typeof(int), typeof(int)};
           object[] aVargs1 = new object[] {10, 10, 10};
           object[] aVargs2 = new object[] {20, 20, 20};
    
       // Call the  method to build our dynamic class.

       IVType = DynamicDotProductGen();

           Console.WriteLine("---");

       ConstructorInfo myDTctor = IVType.GetConstructor(aVtypes);
       aVector1 = myDTctor.Invoke(aVargs1);
       aVector2 = myDTctor.Invoke(aVargs2);

       object[] passMe = new object[1];
           passMe[0] = (object)aVector2;

       Console.WriteLine("(10, 10, 10) . (20, 20, 20) = {0}",
                 IVType.InvokeMember("DotProduct",
                          BindingFlags.InvokeMethod,
                          null,
                          aVector1,
                          passMe));

       // +++ OUTPUT +++
       // ---
       // (10, 10, 10) . (20, 20, 20) = 600
    }
}

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

 _


Class TestILGenerator
   
   
   Public Shared Function DynamicDotProductGen() As Type
      
      Dim ivType As Type = Nothing
      Dim ctorParams() As Type = {GetType(Integer), GetType(Integer), GetType(Integer)}
      
      Dim myDomain As AppDomain = Thread.GetDomain()
      Dim myAsmName As New AssemblyName()
      myAsmName.Name = "IntVectorAsm"
      
      Dim myAsmBuilder As AssemblyBuilder = myDomain.DefineDynamicAssembly( _
                        myAsmName, _
                        AssemblyBuilderAccess.RunAndSave)
      
      Dim IntVectorModule As ModuleBuilder = myAsmBuilder.DefineDynamicModule( _
                         "IntVectorModule", _
                         "Vector.dll")
      
      Dim ivTypeBld As TypeBuilder = IntVectorModule.DefineType("IntVector", TypeAttributes.Public)
      
      Dim xField As FieldBuilder = ivTypeBld.DefineField("x", _
                                 GetType(Integer), _
                                 FieldAttributes.Private)
      Dim yField As FieldBuilder = ivTypeBld.DefineField("y", _ 
                                 GetType(Integer), _
                                 FieldAttributes.Private)
      Dim zField As FieldBuilder = ivTypeBld.DefineField("z", _
                                 GetType(Integer), _
                                 FieldAttributes.Private)
      
      
      Dim objType As Type = Type.GetType("System.Object")
      Dim objCtor As ConstructorInfo = objType.GetConstructor(New Type() {})
      
      Dim ivCtor As ConstructorBuilder = ivTypeBld.DefineConstructor( _
                     MethodAttributes.Public, _
                     CallingConventions.Standard, _
                     ctorParams)
      Dim ctorIL As ILGenerator = ivCtor.GetILGenerator()
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Call, objCtor)
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_1)
      ctorIL.Emit(OpCodes.Stfld, xField)
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_2)
      ctorIL.Emit(OpCodes.Stfld, yField)
      ctorIL.Emit(OpCodes.Ldarg_0)
      ctorIL.Emit(OpCodes.Ldarg_3)
      ctorIL.Emit(OpCodes.Stfld, zField)
      ctorIL.Emit(OpCodes.Ret)
     

      ' Now, you'll construct the method find the dot product of two vectors. First,
      ' let's define the parameters that will be accepted by the method. In this case,
      ' it's an IntVector itself!

      Dim dpParams() As Type = {ivTypeBld}
      
      ' Here, you create a MethodBuilder containing the
      ' name, the attributes (public, static, private, and so on),
      ' the return type (int, in this case), and a array of Type
      ' indicating the type of each parameter. Since the sole parameter
      ' is a IntVector, the very class you're creating, you will
      ' pass in the TypeBuilder (which is derived from Type) instead of 
      ' a Type object for IntVector, avoiding an exception. 
      ' -- This method would be declared in VB.NET as:
      '    Public Function DotProduct(IntVector aVector) As Integer

      Dim dotProductMthd As MethodBuilder = ivTypeBld.DefineMethod("DotProduct", _
                        MethodAttributes.Public, GetType(Integer), _
                                            dpParams)
      
      ' A ILGenerator can now be spawned, attached to the MethodBuilder.
      Dim mthdIL As ILGenerator = dotProductMthd.GetILGenerator()
      
      ' Here's the body of our function, in MSIL form. We're going to find the
      ' "dot product" of the current vector instance with the passed vector 
      ' instance. For reference purposes, the equation is:
      ' (x1 * x2) + (y1 * y2) + (z1 * z2) = the dot product
      ' First, you'll load the reference to the current instance "this"
      ' stored in argument 0 (ldarg.0) onto the stack. Ldfld, the subsequent
      ' instruction, will pop the reference off the stack and look up the
      ' field "x", specified by the FieldInfo token "xField".
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldfld, xField)
      
      ' That completed, the value stored at field "x" is now atop the stack.
      ' Now, you'll do the same for the object reference we passed as a
      ' parameter, stored in argument 1 (ldarg.1). After Ldfld executed,
      ' you'll have the value stored in field "x" for the passed instance
      ' atop the stack.
      mthdIL.Emit(OpCodes.Ldarg_1)
      mthdIL.Emit(OpCodes.Ldfld, xField)
      
      ' There will now be two values atop the stack - the "x" value for the
      ' current vector instance, and the "x" value for the passed instance.
      ' You'll now multiply them, and push the result onto the evaluation stack.
      mthdIL.Emit(OpCodes.Mul_Ovf_Un)
      
      ' Now, repeat this for the "y" fields of both vectors.
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldfld, yField)
      mthdIL.Emit(OpCodes.Ldarg_1)
      mthdIL.Emit(OpCodes.Ldfld, yField)
      mthdIL.Emit(OpCodes.Mul_Ovf_Un)
      
      ' At this time, the results of both multiplications should be atop
      ' the stack. You'll now add them and push the result onto the stack.
      mthdIL.Emit(OpCodes.Add_Ovf_Un)
      
      ' Multiply both "z" field and push the result onto the stack.
      mthdIL.Emit(OpCodes.Ldarg_0)
      mthdIL.Emit(OpCodes.Ldfld, zField)
      mthdIL.Emit(OpCodes.Ldarg_1)
      mthdIL.Emit(OpCodes.Ldfld, zField)
      mthdIL.Emit(OpCodes.Mul_Ovf_Un)
      
      ' Finally, add the result of multiplying the "z" fields with the
      ' result of the earlier addition, and push the result - the dot product -
      ' onto the stack.
      mthdIL.Emit(OpCodes.Add_Ovf_Un)
      
      ' The "ret" opcode will pop the last value from the stack and return it
      ' to the calling method. You're all done!
      mthdIL.Emit(OpCodes.Ret)
      
      
      ivType = ivTypeBld.CreateType()
      
      Return ivType
   End Function 'DynamicDotProductGen
    
   
   Public Shared Sub Main()
      
      Dim IVType As Type = Nothing
      Dim aVector1 As Object = Nothing
      Dim aVector2 As Object = Nothing
      Dim aVtypes() As Type = {GetType(Integer), GetType(Integer), GetType(Integer)}
      Dim aVargs1() As Object = {10, 10, 10}
      Dim aVargs2() As Object = {20, 20, 20}
      
      ' Call the  method to build our dynamic class.
      IVType = DynamicDotProductGen()
      
      
      Dim myDTctor As ConstructorInfo = IVType.GetConstructor(aVtypes)
      aVector1 = myDTctor.Invoke(aVargs1)
      aVector2 = myDTctor.Invoke(aVargs2)
      
      Console.WriteLine("---")
      Dim passMe(0) As Object
      passMe(0) = CType(aVector2, Object)
      
      Console.WriteLine("(10, 10, 10) . (20, 20, 20) = {0}", _
                        IVType.InvokeMember("DotProduct", BindingFlags.InvokeMethod, _
                        Nothing, aVector1, passMe))
   End Sub
End Class



' +++ OUTPUT +++
' ---
' (10, 10, 10) . (20, 20, 20) = 600

Opmerkingen

Zie Aanvullende API-opmerkingen voor TypeBuilder voor meer informatie over deze API.

Zie ook

• Handleiding: Een generiek type definiëren met Reflection Emit