OpCodes 类
通过 ILGenerator 类成员（例如 Emit）为发出提供 Microsoft 中间语言 (MSIL) 指令的字段表示形式。
**命名空间:**System.Reflection.Emit
**程序集:**mscorlib（在 mscorlib.dll 中）
语法
声明
<ComVisibleAttribute(True)> _
Public Class OpCodes
用法
Dim instance As OpCodes
[ComVisibleAttribute(true)]
public class OpCodes
[ComVisibleAttribute(true)]
public ref class OpCodes
/** @attribute ComVisibleAttribute(true) */
public class OpCodes
ComVisibleAttribute(true)
public class OpCodes
备注
有关成员操作码的详细描述，请参见公共语言基础结构 (CLI) 文档，特别是其中的“Partition III: CIL Instruction Set”（第三部分：CIL 指令集）和“Partition II: Metadata Definition and Semantics”（第二部分：元数据定义和语义）。该文档可从下面的网站上联机获得：https://msdn.microsoft.com/net/ecma/ 和 http://www.ecma-international.org/publications/standards/Ecma-335.htm。
示例
下面的示例演示如何使用 ILGenerator 将 OpCodes 发送到 MethodBuilder 来构造动态方法。
Imports System
Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit
_
Class EmitWriteLineDemo
Public Shared Function CreateDynamicType() As Type
Dim ctorParams() As Type = {GetType(Integer), GetType(Integer)}
Dim myDomain As AppDomain = Thread.GetDomain()
Dim myAsmName As New AssemblyName()
myAsmName.Name = "MyDynamicAssembly"
Dim myAsmBuilder As AssemblyBuilder = myDomain.DefineDynamicAssembly(myAsmName, AssemblyBuilderAccess.RunAndSave)
Dim pointModule As ModuleBuilder = myAsmBuilder.DefineDynamicModule("PointModule", "Point.dll")
Dim pointTypeBld As TypeBuilder = pointModule.DefineType("Point", _
TypeAttributes.Public)
Dim xField As FieldBuilder = pointTypeBld.DefineField("x", _
GetType(Integer), _
FieldAttributes.Public)
Dim yField As FieldBuilder = pointTypeBld.DefineField("y", _
GetType(Integer), _
FieldAttributes.Public)
Dim objType As Type = Type.GetType("System.Object")
Dim objCtor As ConstructorInfo = objType.GetConstructor(New Type(){})
Dim pointCtor As ConstructorBuilder = pointTypeBld.DefineConstructor( _
MethodAttributes.Public, _
CallingConventions.Standard, _
ctorParams)
Dim ctorIL As ILGenerator = pointCtor.GetILGenerator()
' First, you build the constructor.
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.Ret)
' Now, you'll build a method to output some information on the
' inside your dynamic class. This method will have the following
' definition in C#:
' Public Sub WritePoint()
Dim writeStrMthd As MethodBuilder = pointTypeBld.DefineMethod("WritePoint", _
MethodAttributes.Public, _
Nothing, Nothing)
Dim writeStrIL As ILGenerator = writeStrMthd.GetILGenerator()
' The below ILGenerator created demonstrates a few ways to create
' string output through STDIN.
' ILGenerator.EmitWriteLine(string) will generate a ldstr and a
' call to WriteLine for you.
writeStrIL.EmitWriteLine("The value of this current instance is:")
' Here, you will do the hard work yourself. First, you need to create
' the string we will be passing and obtain the correct WriteLine overload
' for said string. In the below case, you are substituting in two values,
' so the chosen overload is Console.WriteLine(string, object, object).
Dim inStr As [String] = "({0}, {1})"
Dim wlParams() As Type = {GetType(String), GetType(Object), GetType(Object)}
' We need the MethodInfo to pass into EmitCall later.
Dim writeLineMI As MethodInfo = GetType(Console).GetMethod("WriteLine", wlParams)
' Push the string with the substitutions onto the stack.
' This is the first argument for WriteLine - the string one.
writeStrIL.Emit(OpCodes.Ldstr, inStr)
' Since the second argument is an object, and it corresponds to
' to the substitution for the value of our integer field, you
' need to box that field to an object. First, push a reference
' to the current instance, and then push the value stored in
' field 'x'. We need the reference to the current instance (stored
' in local argument index 0) so Ldfld can load from the correct
' instance (this one).
writeStrIL.Emit(OpCodes.Ldarg_0)
writeStrIL.Emit(OpCodes.Ldfld, xField)
' Now, we execute the box opcode, which pops the value of field 'x',
' returning a reference to the integer value boxed as an object.
writeStrIL.Emit(OpCodes.Box, GetType(Integer))
' Atop the stack, you'll find our string inStr, followed by a reference
' to the boxed value of 'x'. Now, you need to likewise box field 'y'.
writeStrIL.Emit(OpCodes.Ldarg_0)
writeStrIL.Emit(OpCodes.Ldfld, yField)
writeStrIL.Emit(OpCodes.Box, GetType(Integer))
' Now, you have all of the arguments for your call to
' Console.WriteLine(string, object, object) atop the stack:
' the string InStr, a reference to the boxed value of 'x', and
' a reference to the boxed value of 'y'.
' Call Console.WriteLine(string, object, object) with EmitCall.
writeStrIL.EmitCall(OpCodes.Call, writeLineMI, Nothing)
' Lastly, EmitWriteLine can also output the value of a field
' using the overload EmitWriteLine(FieldInfo).
writeStrIL.EmitWriteLine("The value of 'x' is:")
writeStrIL.EmitWriteLine(xField)
writeStrIL.EmitWriteLine("The value of 'y' is:")
writeStrIL.EmitWriteLine(yField)
' Since we return no value (void), the the ret opcode will not
' return the top stack value.
writeStrIL.Emit(OpCodes.Ret)
Return pointTypeBld.CreateType()
End Function 'CreateDynamicType
Public Shared Sub Main()
Dim ctorParams(1) As Object
Console.Write("Enter a integer value for X: ")
Dim myX As String = Console.ReadLine()
Console.Write("Enter a integer value for Y: ")
Dim myY As String = Console.ReadLine()
Console.WriteLine("---")
ctorParams(0) = Convert.ToInt32(myX)
ctorParams(1) = Convert.ToInt32(myY)
Dim ptType As Type = CreateDynamicType()
Dim ptInstance As Object = Activator.CreateInstance(ptType, ctorParams)
ptType.InvokeMember("WritePoint", _
BindingFlags.InvokeMethod, _
Nothing, ptInstance, Nothing)
End Sub 'Main
End Class 'EmitWriteLineDemo
using System;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;
class EmitWriteLineDemo {
public static Type CreateDynamicType() {
Type[] ctorParams = new Type[] {typeof(int),
typeof(int)};
AppDomain myDomain = Thread.GetDomain();
AssemblyName myAsmName = new AssemblyName();
myAsmName.Name = "MyDynamicAssembly";
AssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(
myAsmName,
AssemblyBuilderAccess.RunAndSave);
ModuleBuilder pointModule = myAsmBuilder.DefineDynamicModule("PointModule",
"Point.dll");
TypeBuilder pointTypeBld = pointModule.DefineType("Point",
TypeAttributes.Public);
FieldBuilder xField = pointTypeBld.DefineField("x", typeof(int),
FieldAttributes.Public);
FieldBuilder yField = pointTypeBld.DefineField("y", typeof(int),
FieldAttributes.Public);
Type objType = Type.GetType("System.Object");
ConstructorInfo objCtor = objType.GetConstructor(new Type[0]);
ConstructorBuilder pointCtor = pointTypeBld.DefineConstructor(
MethodAttributes.Public,
CallingConventions.Standard,
ctorParams);
ILGenerator ctorIL = pointCtor.GetILGenerator();
// First, you build the constructor.
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.Ret);
// Now, you'll build a method to output some information on the
// inside your dynamic class. This method will have the following
// definition in C#:
// public void WritePoint()
MethodBuilder writeStrMthd = pointTypeBld.DefineMethod(
"WritePoint",
MethodAttributes.Public,
typeof(void),
null);
ILGenerator writeStrIL = writeStrMthd.GetILGenerator();
// The below ILGenerator created demonstrates a few ways to create
// string output through STDIN.
// ILGenerator.EmitWriteLine(string) will generate a ldstr and a
// call to WriteLine for you.
writeStrIL.EmitWriteLine("The value of this current instance is:");
// Here, you will do the hard work yourself. First, you need to create
// the string we will be passing and obtain the correct WriteLine overload
// for said string. In the below case, you are substituting in two values,
// so the chosen overload is Console.WriteLine(string, object, object).
String inStr = "({0}, {1})";
Type[] wlParams = new Type[] {typeof(string),
typeof(object),
typeof(object)};
// We need the MethodInfo to pass into EmitCall later.
MethodInfo writeLineMI = typeof(Console).GetMethod(
"WriteLine",
wlParams);
// Push the string with the substitutions onto the stack.
// This is the first argument for WriteLine - the string one.
writeStrIL.Emit(OpCodes.Ldstr, inStr);
// Since the second argument is an object, and it corresponds to
// to the substitution for the value of our integer field, you
// need to box that field to an object. First, push a reference
// to the current instance, and then push the value stored in
// field 'x'. We need the reference to the current instance (stored
// in local argument index 0) so Ldfld can load from the correct
// instance (this one).
writeStrIL.Emit(OpCodes.Ldarg_0);
writeStrIL.Emit(OpCodes.Ldfld, xField);
// Now, we execute the box opcode, which pops the value of field 'x',
// returning a reference to the integer value boxed as an object.
writeStrIL.Emit(OpCodes.Box, typeof(int));
// Atop the stack, you'll find our string inStr, followed by a reference
// to the boxed value of 'x'. Now, you need to likewise box field 'y'.
writeStrIL.Emit(OpCodes.Ldarg_0);
writeStrIL.Emit(OpCodes.Ldfld, yField);
writeStrIL.Emit(OpCodes.Box, typeof(int));
// Now, you have all of the arguments for your call to
// Console.WriteLine(string, object, object) atop the stack:
// the string InStr, a reference to the boxed value of 'x', and
// a reference to the boxed value of 'y'.
// Call Console.WriteLine(string, object, object) with EmitCall.
writeStrIL.EmitCall(OpCodes.Call, writeLineMI, null);
// Lastly, EmitWriteLine can also output the value of a field
// using the overload EmitWriteLine(FieldInfo).
writeStrIL.EmitWriteLine("The value of 'x' is:");
writeStrIL.EmitWriteLine(xField);
writeStrIL.EmitWriteLine("The value of 'y' is:");
writeStrIL.EmitWriteLine(yField);
// Since we return no value (void), the the ret opcode will not
// return the top stack value.
writeStrIL.Emit(OpCodes.Ret);
return pointTypeBld.CreateType();
}
public static void Main() {
object[] ctorParams = new object[2];
Console.Write("Enter a integer value for X: ");
string myX = Console.ReadLine();
Console.Write("Enter a integer value for Y: ");
string myY = Console.ReadLine();
Console.WriteLine("---");
ctorParams[0] = Convert.ToInt32(myX);
ctorParams[1] = Convert.ToInt32(myY);
Type ptType = CreateDynamicType();
object ptInstance = Activator.CreateInstance(ptType, ctorParams);
ptType.InvokeMember("WritePoint",
BindingFlags.InvokeMethod,
null,
ptInstance,
new object[0]);
}
}
using namespace System;
using namespace System::Threading;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
Type^ CreateDynamicType()
{
array<Type^>^ctorParams = {int::typeid,int::typeid};
AppDomain^ myDomain = Thread::GetDomain();
AssemblyName^ myAsmName = gcnew AssemblyName;
myAsmName->Name = "MyDynamicAssembly";
AssemblyBuilder^ myAsmBuilder = myDomain->DefineDynamicAssembly( myAsmName, AssemblyBuilderAccess::RunAndSave );
ModuleBuilder^ pointModule = myAsmBuilder->DefineDynamicModule( "PointModule", "Point.dll" );
TypeBuilder^ pointTypeBld = pointModule->DefineType( "Point", TypeAttributes::Public );
FieldBuilder^ xField = pointTypeBld->DefineField( "x", int::typeid, FieldAttributes::Public );
FieldBuilder^ yField = pointTypeBld->DefineField( "y", int::typeid, FieldAttributes::Public );
Type^ objType = Type::GetType( "System.Object" );
ConstructorInfo^ objCtor = objType->GetConstructor( gcnew array<Type^>(0) );
ConstructorBuilder^ pointCtor = pointTypeBld->DefineConstructor( MethodAttributes::Public, CallingConventions::Standard, ctorParams );
ILGenerator^ ctorIL = pointCtor->GetILGenerator();
// First, you build the constructor.
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::Ret );
// Now, you'll build a method to output some information on the
// inside your dynamic class. This method will have the following
// definition in C#:
// public void WritePoint()
MethodBuilder^ writeStrMthd = pointTypeBld->DefineMethod( "WritePoint", MethodAttributes::Public, void::typeid, nullptr );
ILGenerator^ writeStrIL = writeStrMthd->GetILGenerator();
// The below ILGenerator created demonstrates a few ways to create
// String* output through STDIN.
// ILGenerator::EmitWriteLine(String*) will generate a ldstr and a
// call to WriteLine for you.
writeStrIL->EmitWriteLine( "The value of this current instance is:" );
// Here, you will do the hard work yourself. First, you need to create
// the String* we will be passing and obtain the correct WriteLine overload
// for said String*. In the below case, you are substituting in two values,
// so the chosen overload is Console::WriteLine(String*, Object*, Object*).
String^ inStr = "( {0}, {1})";
array<Type^>^wlParams = {String::typeid,Object::typeid,Object::typeid};
// We need the MethodInfo to pass into EmitCall later.
MethodInfo^ writeLineMI = Console::typeid->GetMethod( "WriteLine", wlParams );
// Push the String* with the substitutions onto the stack.
// This is the first argument for WriteLine - the String* one.
writeStrIL->Emit( OpCodes::Ldstr, inStr );
// Since the second argument is an Object*, and it corresponds to
// to the substitution for the value of our integer field, you
// need to box that field to an Object*. First, push a reference
// to the current instance, and then push the value stored in
// field 'x'. We need the reference to the current instance (stored
// in local argument index 0) so Ldfld can load from the correct
// instance (this one).
writeStrIL->Emit( OpCodes::Ldarg_0 );
writeStrIL->Emit( OpCodes::Ldfld, xField );
// Now, we execute the box opcode, which pops the value of field 'x',
// returning a reference to the integer value boxed as an Object*.
writeStrIL->Emit( OpCodes::Box, int::typeid );
// Atop the stack, you'll find our String* inStr, followed by a reference
// to the boxed value of 'x'. Now, you need to likewise box field 'y'.
writeStrIL->Emit( OpCodes::Ldarg_0 );
writeStrIL->Emit( OpCodes::Ldfld, yField );
writeStrIL->Emit( OpCodes::Box, int::typeid );
// Now, you have all of the arguments for your call to
// Console::WriteLine(String*, Object*, Object*) atop the stack:
// the String* InStr, a reference to the boxed value of 'x', and
// a reference to the boxed value of 'y'.
// Call Console::WriteLine(String*, Object*, Object*) with EmitCall.
writeStrIL->EmitCall( OpCodes::Call, writeLineMI, nullptr );
// Lastly, EmitWriteLine can also output the value of a field
// using the overload EmitWriteLine(FieldInfo).
writeStrIL->EmitWriteLine( "The value of 'x' is:" );
writeStrIL->EmitWriteLine( xField );
writeStrIL->EmitWriteLine( "The value of 'y' is:" );
writeStrIL->EmitWriteLine( yField );
// Since we return no value (void), the the ret opcode will not
// return the top stack value.
writeStrIL->Emit( OpCodes::Ret );
return pointTypeBld->CreateType();
}
int main()
{
array<Object^>^ctorParams = gcnew array<Object^>(2);
Console::Write( "Enter a integer value for X: " );
String^ myX = Console::ReadLine();
Console::Write( "Enter a integer value for Y: " );
String^ myY = Console::ReadLine();
Console::WriteLine( "---" );
ctorParams[ 0 ] = Convert::ToInt32( myX );
ctorParams[ 1 ] = Convert::ToInt32( myY );
Type^ ptType = CreateDynamicType();
Object^ ptInstance = Activator::CreateInstance( ptType, ctorParams );
ptType->InvokeMember( "WritePoint", BindingFlags::InvokeMethod, nullptr, ptInstance, gcnew array<Object^>(0) );
}
import System.*;
import System.Threading.*;
import System.Reflection.*;
import System.Reflection.Emit.*;
class EmitWriteLineDemo
{
public static Type CreateDynamicType()
{
Type ctorParams[] = new Type[] { int.class.ToType(),
int.class.ToType() };
AppDomain myDomain = System.Threading.Thread.GetDomain();
AssemblyName myAsmName = new AssemblyName();
myAsmName.set_Name("MyDynamicAssembly");
AssemblyBuilder myAsmBuilder =
myDomain.DefineDynamicAssembly(myAsmName,
AssemblyBuilderAccess.RunAndSave);
ModuleBuilder pointModule = myAsmBuilder.DefineDynamicModule(
"PointModule", "Point.dll");
TypeBuilder pointTypeBld = pointModule.DefineType("Point",
TypeAttributes.Public);
FieldBuilder xField = pointTypeBld.DefineField("x", int.class.ToType(),
FieldAttributes.Public);
FieldBuilder yField = pointTypeBld.DefineField("y", int.class.ToType(),
FieldAttributes.Public);
Type objType = Type.GetType("System.Object");
ConstructorInfo objCtor = objType.GetConstructor(new Type[0]);
ConstructorBuilder pointCtor = pointTypeBld.DefineConstructor
(MethodAttributes.Public, CallingConventions.Standard, ctorParams);
ILGenerator ctorIL = pointCtor.GetILGenerator();
// First, you build the constructor.
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.Ret);
// Now, you'll build a method to output some information on the
// inside your dynamic class. This method will have the following
// definition in VJ#:
// public void WritePoint()
MethodBuilder writeStrMthd = pointTypeBld.DefineMethod("WritePoint",
MethodAttributes.Public, void.class.ToType(), null);
ILGenerator writeStrIL = writeStrMthd.GetILGenerator();
// The below ILGenerator created demonstrates a few ways to create
// string output through STDIN.
// ILGenerator.EmitWriteLine(string) will generate a ldstr and a
// call to WriteLine for you.
writeStrIL.EmitWriteLine("The value of this current instance is:");
// Here, you will do the hard work yourself. First, you need to create
// the string we will be passing and obtain the correct WriteLine
// overload for said string. In the below case, you are substituting
// in two values, so the chosen overload is
// Console.WriteLine(string, object, object).
String inStr = "({0}, {1})";
Type wlParams[] = new Type[] { String.class.ToType(),
Object.class.ToType(), Object.class.ToType() };
// We need the MethodInfo to pass into EmitCall later.
MethodInfo writeLineMI = Console.class.ToType().GetMethod("WriteLine",
wlParams);
// Push the string with the substitutions onto the stack.
// This is the first argument for WriteLine - the string one.
writeStrIL.Emit(OpCodes.Ldstr, inStr);
// Since the second argument is an object, and it corresponds to
// to the substitution for the value of our integer field, you
// need to box that field to an object. First, push a reference
// to the current instance, and then push the value stored in
// field 'x'. We need the reference to the current instance (stored
// in local argument index 0) so Ldfld can load from the correct
// instance (this one).
writeStrIL.Emit(OpCodes.Ldarg_0);
writeStrIL.Emit(OpCodes.Ldfld, xField);
// Now, we execute the box opcode, which pops the value of field 'x',
// returning a reference to the integer value boxed as an object.
writeStrIL.Emit(OpCodes.Box, int.class.ToType());
// Atop the stack, you'll find our string inStr, followed by a
// reference to the boxed value of 'x'. Now, you need to likewise
// box field 'y'.
writeStrIL.Emit(OpCodes.Ldarg_0);
writeStrIL.Emit(OpCodes.Ldfld, yField);
writeStrIL.Emit(OpCodes.Box, int.class.ToType());
// Now, you have all of the arguments for your call to
// Console.WriteLine(string, object, object) atop the stack:
// the string InStr, a reference to the boxed value of 'x', and
// a reference to the boxed value of 'y'.
// Call Console.WriteLine(string, object, object) with EmitCall.
writeStrIL.EmitCall(OpCodes.Call, writeLineMI, null);
// Lastly, EmitWriteLine can also output the value of a field
// using the overload EmitWriteLine(FieldInfo).
writeStrIL.EmitWriteLine("The value of 'x' is:");
writeStrIL.EmitWriteLine(xField);
writeStrIL.EmitWriteLine("The value of 'y' is:");
writeStrIL.EmitWriteLine(yField);
// Since we return no value (void), the the ret opcode will not
// return the top stack value.
writeStrIL.Emit(OpCodes.Ret);
return pointTypeBld.CreateType();
} //CreateDynamicType
public static void main(String[] args)
{
Object ctorParams[] = new Object[2];
Console.Write("Enter a integer value for X: ");
String myX = Console.ReadLine();
Console.Write("Enter a integer value for Y: ");
String myY = Console.ReadLine();
Console.WriteLine("---");
ctorParams[0] = (Int32)Integer.parseInt(myX);
ctorParams[1] = (Int32)Integer.parseInt(myY);
Type ptType = CreateDynamicType();
Object ptInstance = Activator.CreateInstance(ptType, ctorParams);
ptType.InvokeMember("WritePoint", BindingFlags.InvokeMethod, null,
ptInstance, new Object[0]);
} //main
} //EmitWriteLineDemo
继承层次结构
System.Object
System.Reflection.Emit.OpCodes
线程安全
此类型的任何公共静态（Visual Basic 中的 Shared）成员都是线程安全的，但不保证所有实例成员都是线程安全的。
平台
Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0