TypeBuilder Class
Defines and creates new instances of classes during runtime.
For a list of all members of this type, see TypeBuilder Members.
System.Object
System.Reflection.MemberInfo
System.Type
System.Reflection.Emit.TypeBuilder
[Visual Basic] NotInheritable Public Class TypeBuilder Inherits Type [C#] public sealed class TypeBuilder : Type [C++] public __gc __sealed class TypeBuilder : public Type [JScript] public class TypeBuilder extends Type
Thread Safety
Reflection Emit is thread-safe when using assemblies that were created with the AppDomain.DefineDynamicAssembly method with the Boolean parameter isSynchronized set to true.
Remarks
TypeBuilder is the root class used to control the creation of dynamic classes in the runtime. TypeBuilder provides a set of routines that are used to define classes, add methods and fields, and create the class inside the runtime. A new TypeBuilder can be created from a dynamic module.
To retrieve a Type object for an incomplete type, use ModuleBuilder.GetType with a string representing the type name, such as "MyType" or "MyType[]".
Example
[Visual Basic, C#, C++] The following code sample demonstrates how to build a dynamic type using TypeBuilder.
[Visual Basic] Imports System 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 'Main End Class 'TestILGenerator ' +++ OUTPUT +++ ' --- ' (10, 10, 10) . (20, 20, 20) = 600 [C#] 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 } } [C++] #using <mscorlib.dll> using namespace System; using namespace System::Threading; using namespace System::Reflection; using namespace System::Reflection::Emit; Type* DynamicDotProductGen() { Type* ivType = 0; Type* temp0 [] = {__typeof(int), __typeof(int), __typeof(int)}; Type* ctorParams[] = temp0; AppDomain* myDomain = Thread::GetDomain(); AssemblyName* myAsmName = new AssemblyName(); myAsmName->Name = S"IntVectorAsm"; AssemblyBuilder* myAsmBuilder = myDomain->DefineDynamicAssembly(myAsmName, AssemblyBuilderAccess::RunAndSave); ModuleBuilder* IntVectorModule = myAsmBuilder->DefineDynamicModule(S"IntVectorModule", S"Vector.dll"); TypeBuilder* ivTypeBld = IntVectorModule->DefineType(S"IntVector", TypeAttributes::Public); FieldBuilder* xField = ivTypeBld->DefineField(S"x", __typeof(int), FieldAttributes::Private); FieldBuilder* yField = ivTypeBld->DefineField(S"y", __typeof(int), FieldAttributes::Private); FieldBuilder* zField = ivTypeBld->DefineField(S"z", __typeof(int), FieldAttributes::Private); Type* objType = Type::GetType(S"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* temp1 [] = {ivTypeBld}; Type* dpParams[] = temp1; // 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(S"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; } int main() { Type* IVType = 0; Object* aVector1 = 0; Object* aVector2 = 0; Type* temp2 [] = {__typeof(int), __typeof(int), __typeof(int)}; Type* aVtypes[] = temp2; Object* temp3 [] = {__box(10), __box(10), __box(10)}; Object* aVargs1[] = temp3; Object* temp4 [] = {__box(20), __box(20), __box(20)}; Object* aVargs2[] = temp4; // Call the method to build our dynamic class. IVType = DynamicDotProductGen(); Console::WriteLine(S"---"); ConstructorInfo* myDTctor = IVType->GetConstructor(aVtypes); aVector1 = myDTctor->Invoke(aVargs1); aVector2 = myDTctor->Invoke(aVargs2); Object* passMe[] = new Object*[1]; passMe->Item[0] = dynamic_cast<Object*>(aVector2); Console::WriteLine(S"(10, 10, 10) . (20, 20, 20) = {0}", IVType->InvokeMember(S"DotProduct", BindingFlags::InvokeMethod, 0, aVector1, passMe)); } // +++ OUTPUT +++ // --- // (10, 10, 10) . (20, 20, 20) = 600
[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Namespace: System.Reflection.Emit
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family
Assembly: Mscorlib (in Mscorlib.dll)