HOW TO：定義和執行動態方法
更新：2007 年 11 月
下列程序將示範如何定義及執行簡單的動態方法及繫結至類別執行個體的動態方法。如需動態方法的詳細資訊，請參閱 DynamicMethod 類別和反映發出動態方法案例。
若要定義及執行動態方法
宣告委派型別來執行此方法。請考慮使用泛型委派，將您需要宣告的委派型別數目減至最少。下列程式碼將宣告兩個可用於 SquareIt 方法的委派型別，而其中一個是泛型。
Private Delegate Function _ SquareItInvoker(ByVal input As Integer) As Long Private Delegate Function _ OneParameter(Of TReturn, TParameter0) _ (ByVal p0 As TParameter0) As TReturnprivate delegate long SquareItInvoker(int input); private delegate TReturn OneParameter<TReturn, TParameter0> (TParameter0 p0);private: delegate long long SquareItInvoker(int input); generic<typename TReturn, typename TParameter0> delegate TReturn OneParameter(TParameter0 p0);建立一個陣列，此陣列可為動態方法指定參數型別。在此範例中，唯一的參數是 int (Visual Basic 中為 Integer)，所以此陣列只有一個元素。
Dim methodArgs As Type() = { GetType(Integer) }Type[] methodArgs = {typeof(int)};array<Type^>^ methodArgs = { int::typeid };建立 DynamicMethod。在此範例中，此方法命名為 SquareIt。
.gif "注意事項")
注意事項：不需要提供動態方法名稱，也不能根據名稱來叫用這些方法。可以讓多個動態方法有相同的名稱；但是，此名稱會出現在呼叫堆疊中，且對於偵錯可能很有用處。
傳回值的型別會指定為 long。此方法會與包含 Example 類別的模組產生關聯，而此類別包含了範例程式碼；任何載入的模組都可以指定。動態方法的運作方式就像是模組層級的 static 方法 (Visual Basic 中為 Shared)。
Dim squareIt As New DynamicMethod( _ "SquareIt", _ GetType(Long), _ methodArgs, _ GetType(Example).Module)DynamicMethod squareIt = new DynamicMethod( "SquareIt", typeof(long), methodArgs, typeof(Example).Module);DynamicMethod^ squareIt = gcnew DynamicMethod( "SquareIt", long long::typeid, methodArgs, Example::typeid->Module);發出方法主體。在此範例中，會使用 ILGenerator 物件來發出 Microsoft intermediate language (MSIL)。另外，也可以將 DynamicILInfo 物件搭配 Unmanaged 程式碼產生器一起使用，以發出 DynamicMethod 的方法主體。
此範例中的 MSIL 會將引數 (亦即 int) 載入到堆疊上、將它轉換成 long、複製 long，並將這兩個數字相乘。如此會讓相乘的結果留在堆疊上，而所有方法必須做的事情就是傳回。
Dim il As ILGenerator = squareIt.GetILGenerator() il.Emit(OpCodes.Ldarg_0) il.Emit(OpCodes.Conv_I8) il.Emit(OpCodes.Dup) il.Emit(OpCodes.Mul) il.Emit(OpCodes.Ret)ILGenerator il = squareIt.GetILGenerator(); il.Emit(OpCodes.Ldarg_0); il.Emit(OpCodes.Conv_I8); il.Emit(OpCodes.Dup); il.Emit(OpCodes.Mul); il.Emit(OpCodes.Ret);ILGenerator^ il = squareIt->GetILGenerator(); il->Emit(OpCodes::Ldarg_0); il->Emit(OpCodes::Conv_I8); il->Emit(OpCodes::Dup); il->Emit(OpCodes::Mul); il->Emit(OpCodes::Ret);藉由呼叫 CreateDelegate 方法來建立委派的執行個體 (步驟 1 中所宣告)，其表示動態方法。建立此委派即會完成此方法，而任何進一步嘗試變更此方法的動作 (例如，加入更多的 MSIL) 都會被忽略。下列程式碼會使用泛型委派，以建立委派並叫用它。
Dim invokeSquareIt As OneParameter(Of Long, Integer) = _ CType( _ squareIt.CreateDelegate( _ GetType(OneParameter(Of Long, Integer))), _ OneParameter(Of Long, Integer) _ ) Console.WriteLine("123456789 squared = {0}", _ invokeSquareIt(123456789))OneParameter<long, int> invokeSquareIt = (OneParameter<long, int>) squareIt.CreateDelegate(typeof(OneParameter<long, int>)); Console.WriteLine("123456789 squared = {0}", invokeSquareIt(123456789));OneParameter<long long, int>^ invokeSquareIt = (OneParameter<long long, int>^) squareIt->CreateDelegate(OneParameter<long long, int>::typeid); Console::WriteLine("123456789 squared = {0}", invokeSquareIt(123456789));
若要定義及執行繫結至物件的動態方法
宣告委派型別來執行此方法。請考慮使用泛型委派，將您需要宣告的委派型別數目減至最少。下列程式碼會宣告可用來執行任何具有一個參數和一個傳回值的方法之泛型委派型別；如果此委派繫結至物件，則為具有兩個參數和一個傳回值的方法。
Private Delegate Function _ OneParameter(Of TReturn, TParameter0) _ (ByVal p0 As TParameter0) As TReturnprivate delegate TReturn OneParameter<TReturn, TParameter0> (TParameter0 p0);generic<typename TReturn, typename TParameter0> delegate TReturn OneParameter(TParameter0 p0);建立一個陣列，此陣列可為動態方法指定參數型別。如果表示此方法的委派要繫結至物件，則第一個參數必須符合此委派所繫結的型別。此範例中有兩個參數，其型別為 Example 和型別 int (Visual Basic 中為 Integer)。
Dim methodArgs2 As Type() = _ { GetType(Example), GetType(Integer) }Type[] methodArgs2 = { typeof(Example), typeof(int) };array<Type^>^ methodArgs2 = { Example::typeid, int::typeid };建立 DynamicMethod。在此範例中，此方法沒有名稱。傳回值的型別會指定為 int (Visual Basic 中為 Integer)。此方法對於 Example 類別的私用和受保護的成員具有存取權。
Dim multiplyPrivate As New DynamicMethod( _ "", _ GetType(Integer), _ methodArgs2, _ GetType(Example))DynamicMethod multiplyHidden = new DynamicMethod( "", typeof(int), methodArgs2, typeof(Example));DynamicMethod^ multiplyHidden = gcnew DynamicMethod( "", int::typeid, methodArgs2, Example::typeid);發出方法主體。在此範例中，會使用 ILGenerator 物件來發出 Microsoft intermediate language (MSIL)。另外，也可以將 DynamicILInfo 物件搭配 Unmanaged 程式碼產生器一起使用，以發出 DynamicMethod 的方法主體。
此範例中的 MSIL 會載入第一個引數 (此引數為 Example 類別的執行個體)，並使用它來載入型別為 int 的私用執行個體欄位的值。第二個引數也會載入，而這兩個數字會相乘。如果相乘結果大於 int，則這個值會被截斷，且會捨棄最明顯的位元。然後此方法會傳回，且包含堆疊上的傳回值。
Dim ilMP As ILGenerator = multiplyPrivate.GetILGenerator() ilMP.Emit(OpCodes.Ldarg_0) Dim testInfo As FieldInfo = _ GetType(Example).GetField("test", _ BindingFlags.NonPublic Or BindingFlags.Instance) ilMP.Emit(OpCodes.Ldfld, testInfo) ilMP.Emit(OpCodes.Ldarg_1) ilMP.Emit(OpCodes.Mul) ilMP.Emit(OpCodes.Ret)ILGenerator ilMH = multiplyHidden.GetILGenerator(); ilMH.Emit(OpCodes.Ldarg_0); FieldInfo testInfo = typeof(Example).GetField("test", BindingFlags.NonPublic | BindingFlags.Instance); ilMH.Emit(OpCodes.Ldfld, testInfo); ilMH.Emit(OpCodes.Ldarg_1); ilMH.Emit(OpCodes.Mul); ilMH.Emit(OpCodes.Ret);ILGenerator^ ilMH = multiplyHidden->GetILGenerator(); ilMH->Emit(OpCodes::Ldarg_0); FieldInfo^ testInfo = Example::typeid->GetField("test", BindingFlags::NonPublic | BindingFlags::Instance); ilMH->Emit(OpCodes::Ldfld, testInfo); ilMH->Emit(OpCodes::Ldarg_1); ilMH->Emit(OpCodes::Mul); ilMH->Emit(OpCodes::Ret);藉由呼叫 CreateDelegate(Type, Object) 方法多載來建立委派的執行個體 (步驟 1 中所宣告)，其表示動態方法。建立此委派即會完成此方法，而任何進一步嘗試變更此方法的動作 (例如，加入更多的 MSIL) 都會被忽略。
注意事項：您可以呼叫 CreateDelegate 方法多次，以建立繫結至其他目標型別執行個體的委派。
下列程式碼會將此方法繫結至 Example 類別的新執行個體，而此類別的私用測試欄位設定為 42；也就是說，每當叫用此委派時，Example 的執行個體即會傳遞給此方法的第一個參數。
會使用委派 OneParameter，因為此方法的第一個參數一定會收到 Example 的執行個體。當叫用此委派時，只需要第二個參數。
Dim invoke As OneParameter(Of Integer, Integer) = _ CType( _ multiplyPrivate.CreateDelegate( _ GetType(OneParameter(Of Integer, Integer)), _ new Example(42) _ ), _ OneParameter(Of Integer, Integer) _ ) Console.WriteLine("3 * test = {0}", invoke(3))OneParameter<int, int> invoke = (OneParameter<int, int>) multiplyHidden.CreateDelegate( typeof(OneParameter<int, int>), new Example(42) ); Console.WriteLine("3 * test = {0}", invoke(3));OneParameter<int, int>^ invoke = (OneParameter<int, int>^) multiplyHidden->CreateDelegate( OneParameter<int, int>::typeid, gcnew Example(42) ); Console::WriteLine("3 * test = {0}", invoke(3));
範例
下列程式碼範例將示範簡單的動態方法，以及繫結至類別執行個體的動態方法。
此簡單的動態方法會接受一個引數 (亦即 32 位元整數)，並傳回該整數的 64 位元平方；會使用泛型委派來叫用此方法。
第二個動態方法有兩個參數，其型別為 Example 和型別 int (Visual Basic 中為 Integer)。當建立此動態方法時，它會繫結至 Example 的執行個體，其方式是使用具有一個型別為 int 的引數之泛型委派。此委派沒有型別 Example 的引數，因為此方法的第一個參數一定會收到 Example 的繫結執行個體。當叫用此委派時，只會提供 int 引數。這個動態方法會存取 Example 類別的私用欄位，並傳回此私用欄位和 int 引數的乘積。
此程式碼範例會定義可用來執行方法的委派。
Imports System
Imports System.Reflection
Imports System.Reflection.Emit
Public Class Example
' The following constructor and private field are used to
' demonstrate a method bound to an object.
'
Private test As Integer
Public Sub New(ByVal test As Integer)
Me.test = test
End Sub
' Declare delegates that can be used to execute the completed
' SquareIt dynamic method. The OneParameter delegate can be
' used to execute any method with one parameter and a return
' value, or a method with two parameters and a return value
' if the delegate is bound to an object.
'
Private Delegate Function _
SquareItInvoker(ByVal input As Integer) As Long
Private Delegate Function _
OneParameter(Of TReturn, TParameter0) _
(ByVal p0 As TParameter0) As TReturn
Public Shared Sub Main()
' Example 1: A simple dynamic method.
'
' Create an array that specifies the parameter types for the
' dynamic method. In this example the only parameter is an
' Integer, so the array has only one element.
'
Dim methodArgs As Type() = { GetType(Integer) }
' Create a DynamicMethod. In this example the method is
' named SquareIt. It is not necessary to give dynamic
' methods names. They cannot be invoked by name, and two
' dynamic methods can have the same name. However, the
' name appears in calls stacks and can be useful for
' debugging.
'
' In this example the return type of the dynamic method
' is Long. The method is associated with the module that
' contains the Example class. Any loaded module could be
' specified. The dynamic method is like a module-level
' Shared method.
'
Dim squareIt As New DynamicMethod( _
"SquareIt", _
GetType(Long), _
methodArgs, _
GetType(Example).Module)
' Emit the method body. In this example ILGenerator is used
' to emit the MSIL. DynamicMethod has an associated type
' DynamicILInfo that can be used in conjunction with
' unmanaged code generators.
'
' The MSIL loads the argument, which is an Integer, onto the
' stack, converts the Integer to a Long, duplicates the top
' item on the stack, and multiplies the top two items on the
' stack. This leaves the squared number on the stack, and
' all the method has to do is return.
'
Dim il As ILGenerator = squareIt.GetILGenerator()
il.Emit(OpCodes.Ldarg_0)
il.Emit(OpCodes.Conv_I8)
il.Emit(OpCodes.Dup)
il.Emit(OpCodes.Mul)
il.Emit(OpCodes.Ret)
' Create a delegate that represents the dynamic method.
' Creating the delegate completes the method, and any further
' attempts to change the method (for example, by adding more
' MSIL) are ignored. The following code uses a generic
' delegate that can produce delegate types matching any
' single-parameter method that has a return type.
'
Dim invokeSquareIt As OneParameter(Of Long, Integer) = _
CType( _
squareIt.CreateDelegate( _
GetType(OneParameter(Of Long, Integer))), _
OneParameter(Of Long, Integer) _
)
Console.WriteLine("123456789 squared = {0}", _
invokeSquareIt(123456789))
' Example 2: A dynamic method bound to an instance.
'
' Create an array that specifies the parameter types for a
' dynamic method. If the delegate representing the method
' is to be bound to an object, the first parameter must
' match the type the delegate is bound to. In the following
' code the bound instance is of the Example class.
'
Dim methodArgs2 As Type() = _
{ GetType(Example), GetType(Integer) }
' Create a DynamicMethod. In this example the method has no
' name. The return type of the method is Integer. The method
' has access to the protected and private members of the
' Example class.
'
Dim multiplyPrivate As New DynamicMethod( _
"", _
GetType(Integer), _
methodArgs2, _
GetType(Example))
' Emit the method body. In this example ILGenerator is used
' to emit the MSIL. DynamicMethod has an associated type
' DynamicILInfo that can be used in conjunction with
' unmanaged code generators.
'
' The MSIL loads the first argument, which is an instance of
' the Example class, and uses it to load the value of a
' private instance field of type Integer. The second argument
' is loaded, and the two numbers are multiplied. If the result
' is larger than Integer, the value is truncated and the most
' significant bits are discarded. The method returns, with
' the return value on the stack.
'
Dim ilMP As ILGenerator = multiplyPrivate.GetILGenerator()
ilMP.Emit(OpCodes.Ldarg_0)
Dim testInfo As FieldInfo = _
GetType(Example).GetField("test", _
BindingFlags.NonPublic Or BindingFlags.Instance)
ilMP.Emit(OpCodes.Ldfld, testInfo)
ilMP.Emit(OpCodes.Ldarg_1)
ilMP.Emit(OpCodes.Mul)
ilMP.Emit(OpCodes.Ret)
' Create a delegate that represents the dynamic method.
' Creating the delegate completes the method, and any further
' attempts to change the method for example, by adding more
' MSIL are ignored.
'
' The following code binds the method to a new instance
' of the Example class whose private test field is set to 42.
' That is, each time the delegate is invoked the instance of
' Example is passed to the first parameter of the method.
'
' The delegate OneParameter is used, because the first
' parameter of the method receives the instance of Example.
' When the delegate is invoked, only the second parameter is
' required.
'
Dim invoke As OneParameter(Of Integer, Integer) = _
CType( _
multiplyPrivate.CreateDelegate( _
GetType(OneParameter(Of Integer, Integer)), _
new Example(42) _
), _
OneParameter(Of Integer, Integer) _
)
Console.WriteLine("3 * test = {0}", invoke(3))
End Sub
End Class
' This code example produces the following output:
'
'123456789 squared = 15241578750190521
'3 * test = 126
'
using System;
using System.Reflection;
using System.Reflection.Emit;
public class Example
{
// The following constructor and private field are used to
// demonstrate a method bound to an object.
private int test;
public Example(int test) { this.test = test; }
// Declare delegates that can be used to execute the completed
// SquareIt dynamic method. The OneParameter delegate can be
// used to execute any method with one parameter and a return
// value, or a method with two parameters and a return value
// if the delegate is bound to an object.
//
private delegate long SquareItInvoker(int input);
private delegate TReturn OneParameter<TReturn, TParameter0>
(TParameter0 p0);
public static void Main()
{
// Example 1: A simple dynamic method.
//
// Create an array that specifies the parameter types for the
// dynamic method. In this example the only parameter is an
// int, so the array has only one element.
//
Type[] methodArgs = {typeof(int)};
// Create a DynamicMethod. In this example the method is
// named SquareIt. It is not necessary to give dynamic
// methods names. They cannot be invoked by name, and two
// dynamic methods can have the same name. However, the
// name appears in calls stacks and can be useful for
// debugging.
//
// In this example the return type of the dynamic method
// is long. The method is associated with the module that
// contains the Example class. Any loaded module could be
// specified. The dynamic method is like a module-level
// static method.
//
DynamicMethod squareIt = new DynamicMethod(
"SquareIt",
typeof(long),
methodArgs,
typeof(Example).Module);
// Emit the method body. In this example ILGenerator is used
// to emit the MSIL. DynamicMethod has an associated type
// DynamicILInfo that can be used in conjunction with
// unmanaged code generators.
//
// The MSIL loads the argument, which is an int, onto the
// stack, converts the int to a long, duplicates the top
// item on the stack, and multiplies the top two items on the
// stack. This leaves the squared number on the stack, and
// all the method has to do is return.
//
ILGenerator il = squareIt.GetILGenerator();
il.Emit(OpCodes.Ldarg_0);
il.Emit(OpCodes.Conv_I8);
il.Emit(OpCodes.Dup);
il.Emit(OpCodes.Mul);
il.Emit(OpCodes.Ret);
// Create a delegate that represents the dynamic method.
// Creating the delegate completes the method, and any further
// attempts to change the method (for example, by adding more
// MSIL) are ignored. The following code uses a generic
// delegate that can produce delegate types matching any
// single-parameter method that has a return type.
//
OneParameter<long, int> invokeSquareIt =
(OneParameter<long, int>)
squareIt.CreateDelegate(typeof(OneParameter<long, int>));
Console.WriteLine("123456789 squared = {0}",
invokeSquareIt(123456789));
// Example 2: A dynamic method bound to an instance.
//
// Create an array that specifies the parameter types for a
// dynamic method. If the delegate representing the method
// is to be bound to an object, the first parameter must
// match the type the delegate is bound to. In the following
// code the bound instance is of the Example class.
//
Type[] methodArgs2 = { typeof(Example), typeof(int) };
// Create a DynamicMethod. In this example the method has no
// name. The return type of the method is int. The method
// has access to the protected and private data of the
// Example class.
//
DynamicMethod multiplyHidden = new DynamicMethod(
"",
typeof(int),
methodArgs2,
typeof(Example));
// Emit the method body. In this example ILGenerator is used
// to emit the MSIL. DynamicMethod has an associated type
// DynamicILInfo that can be used in conjunction with
// unmanaged code generators.
//
// The MSIL loads the first argument, which is an instance of
// the Example class, and uses it to load the value of a
// private instance field of type int. The second argument is
// loaded, and the two numbers are multiplied. If the result
// is larger than int, the value is truncated and the most
// significant bits are discarded. The method returns, with
// the return value on the stack.
//
ILGenerator ilMH = multiplyHidden.GetILGenerator();
ilMH.Emit(OpCodes.Ldarg_0);
FieldInfo testInfo = typeof(Example).GetField("test",
BindingFlags.NonPublic | BindingFlags.Instance);
ilMH.Emit(OpCodes.Ldfld, testInfo);
ilMH.Emit(OpCodes.Ldarg_1);
ilMH.Emit(OpCodes.Mul);
ilMH.Emit(OpCodes.Ret);
// Create a delegate that represents the dynamic method.
// Creating the delegate completes the method, and any further
// attempts to change the method for example, by adding more
// MSIL are ignored.
//
// The following code binds the method to a new instance
// of the Example class whose private test field is set to 42.
// That is, each time the delegate is invoked the instance of
// Example is passed to the first parameter of the method.
//
// The delegate OneParameter is used, because the first
// parameter of the method receives the instance of Example.
// When the delegate is invoked, only the second parameter is
// required.
//
OneParameter<int, int> invoke = (OneParameter<int, int>)
multiplyHidden.CreateDelegate(
typeof(OneParameter<int, int>),
new Example(42)
);
Console.WriteLine("3 * test = {0}", invoke(3));
}
}
/* This code example produces the following output:
123456789 squared = 15241578750190521
3 * test = 126
*/
using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
public ref class Example
{
// The following constructor and private field are used to
// demonstrate a method bound to an object.
private:
int test;
public:
Example(int test) { this->test = test; }
// Declare delegates that can be used to execute the completed
// SquareIt dynamic method. The OneParameter delegate can be
// used to execute any method with one parameter and a return
// value, or a method with two parameters and a return value
// if the delegate is bound to an object.
//
private:
delegate long long SquareItInvoker(int input);
generic<typename TReturn, typename TParameter0>
delegate TReturn OneParameter(TParameter0 p0);
public:
static void Main()
{
// Example 1: A simple dynamic method.
//
// Create an array that specifies the parameter types for the
// dynamic method. In this example the only parameter is an
// int, so the array has only one element.
//
array<Type^>^ methodArgs = { int::typeid };
// Create a DynamicMethod. In this example the method is
// named SquareIt. It is not necessary to give dynamic
// methods names. They cannot be invoked by name, and two
// dynamic methods can have the same name. However, the
// name appears in calls stacks and can be useful for
// debugging.
//
// In this example the return type of the dynamic method is
// long long. The method is associated with the module that
// contains the Example class. Any loaded module could be
// specified. The dynamic method is like a module-level
// static method.
//
DynamicMethod^ squareIt = gcnew DynamicMethod(
"SquareIt",
long long::typeid,
methodArgs,
Example::typeid->Module);
// Emit the method body. In this example ILGenerator is used
// to emit the MSIL. DynamicMethod has an associated type
// DynamicILInfo that can be used in conjunction with
// unmanaged code generators.
//
// The MSIL loads the argument, which is an int, onto the
// stack, converts the int to a long long, duplicates the top
// item on the stack, and multiplies the top two items on the
// stack. This leaves the squared number on the stack, and
// all the method has to do is return.
//
ILGenerator^ il = squareIt->GetILGenerator();
il->Emit(OpCodes::Ldarg_0);
il->Emit(OpCodes::Conv_I8);
il->Emit(OpCodes::Dup);
il->Emit(OpCodes::Mul);
il->Emit(OpCodes::Ret);
// Create a delegate that represents the dynamic method.
// Creating the delegate completes the method, and any further
// attempts to change the method (for example, by adding more
// MSIL) are ignored. The following code uses a generic
// delegate that can produce delegate types matching any
// single-parameter method that has a return type.
//
OneParameter<long long, int>^ invokeSquareIt =
(OneParameter<long long, int>^)
squareIt->CreateDelegate(OneParameter<long long, int>::typeid);
Console::WriteLine("123456789 squared = {0}",
invokeSquareIt(123456789));
// Example 2: A dynamic method bound to an instance.
//
// Create an array that specifies the parameter types for a
// dynamic method. If the delegate representing the method
// is to be bound to an object, the first parameter must
// match the type the delegate is bound to. In the following
// code the bound instance is of the Example class.
//
array<Type^>^ methodArgs2 = { Example::typeid, int::typeid };
// Create a DynamicMethod. In this example the method has no
// name. The return type of the method is int. The method
// has access to the protected and private data of the
// Example class.
//
DynamicMethod^ multiplyHidden = gcnew DynamicMethod(
"",
int::typeid,
methodArgs2,
Example::typeid);
// Emit the method body. In this example ILGenerator is used
// to emit the MSIL. DynamicMethod has an associated type
// DynamicILInfo that can be used in conjunction with
// unmanaged code generators.
//
// The MSIL loads the first argument, which is an instance of
// the Example class, and uses it to load the value of a
// private instance field of type int. The second argument is
// loaded, and the two numbers are multiplied. If the result
// is larger than int, the value is truncated and the most
// significant bits are discarded. The method returns, with
// the return value on the stack.
//
ILGenerator^ ilMH = multiplyHidden->GetILGenerator();
ilMH->Emit(OpCodes::Ldarg_0);
FieldInfo^ testInfo = Example::typeid->GetField("test",
BindingFlags::NonPublic | BindingFlags::Instance);
ilMH->Emit(OpCodes::Ldfld, testInfo);
ilMH->Emit(OpCodes::Ldarg_1);
ilMH->Emit(OpCodes::Mul);
ilMH->Emit(OpCodes::Ret);
// Create a delegate that represents the dynamic method.
// Creating the delegate completes the method, and any further
// attempts to change the method for example, by adding more
// MSIL are ignored.
//
// The following code binds the method to a new instance
// of the Example class whose private test field is set to 42.
// That is, each time the delegate is invoked the instance of
// Example is passed to the first parameter of the method.
//
// The delegate OneParameter is used, because the first
// parameter of the method receives the instance of Example.
// When the delegate is invoked, only the second parameter is
// required.
//
OneParameter<int, int>^ invoke = (OneParameter<int, int>^)
multiplyHidden->CreateDelegate(
OneParameter<int, int>::typeid,
gcnew Example(42)
);
Console::WriteLine("3 * test = {0}", invoke(3));
}
};
void main()
{
Example::Main();
}
/* This code example produces the following output:
123456789 squared = 15241578750190521
3 * test = 126
*/
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