MethodBuilder.GetILGenerator Метод
Определение
Важно!
Некоторые сведения относятся к предварительной версии продукта, в которую до выпуска могут быть внесены существенные изменения. Майкрософт не предоставляет никаких гарантий, явных или подразумеваемых, относительно приведенных здесь сведений.
ILGenerator Возвращает для этого метода.
Перегрузки
| Имя | Описание |
|---|---|
| GetILGenerator() |
Возвращает |
| GetILGenerator(Int32) |
Возвращает |
GetILGenerator()
- Исходный код:
- MethodBuilder.cs
- Исходный код:
- MethodBuilder.cs
- Исходный код:
- MethodBuilder.cs
- Исходный код:
- MethodBuilder.cs
- Исходный код:
- MethodBuilder.cs
Возвращает ILGenerator для этого метода с размером потока по умолчанию Microsoft промежуточного языка (MSIL) размером 64 байта.
public:
System::Reflection::Emit::ILGenerator ^ GetILGenerator();
public System.Reflection.Emit.ILGenerator GetILGenerator();
member this.GetILGenerator : unit -> System.Reflection.Emit.ILGenerator
Public Function GetILGenerator () As ILGenerator
Возвращаемое значение
ILGenerator Возвращает объект для этого метода.
Исключения
Метод не должен иметь текст из-за его MethodAttributes или MethodImplAttributes флагов, например, так как он имеет PinvokeImpl флаг.
–или–
Этот метод является универсальным методом, но не определением универсального метода. То есть свойство равноIsGenericMethod, true но IsGenericMethodDefinition свойство .false
Примеры
В приведенном ниже примере кода показано контекстное использование GetILGenerator метода, создание и создание динамической сборки, которая вычисляет точечный продукт двух точек в трехмерном пространстве.
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
Применяется к
GetILGenerator(Int32)
- Исходный код:
- MethodBuilder.cs
- Исходный код:
- MethodBuilder.cs
- Исходный код:
- MethodBuilder.cs
- Исходный код:
- MethodBuilder.cs
- Исходный код:
- MethodBuilder.cs
Возвращает ILGenerator для этого метода с указанным размером потока Microsoft промежуточного языка (MSIL).
public:
System::Reflection::Emit::ILGenerator ^ GetILGenerator(int size);
public System.Reflection.Emit.ILGenerator GetILGenerator(int size);
member this.GetILGenerator : int -> System.Reflection.Emit.ILGenerator
Public Function GetILGenerator (size As Integer) As ILGenerator
Параметры
- size
- Int32
Размер потока MSIL в байтах.
Возвращаемое значение
ILGenerator Возвращает объект для этого метода.
Исключения
Метод не должен иметь текст из-за его MethodAttributes или MethodImplAttributes флагов, например, так как он имеет PinvokeImpl флаг.
–или–
Этот метод является универсальным методом, но не определением универсального метода. То есть свойство равноIsGenericMethod, true но IsGenericMethodDefinition свойство .false
Примеры
В приведенном ниже примере кода показано контекстное использование GetILGenerator метода, создание и создание динамической сборки, которая вычисляет точечный продукт двух точек в трехмерном пространстве.
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