ModuleBuilder.DefinePInvokeMethod Method

Reference

Definition

Namespace:: System.Reflection.Emit

Assemblies:: netstandard.dll, System.Reflection.Emit.dll

Assembly:: System.Reflection.Emit.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Defines a PInvoke method.

Overloads

DefinePInvokeMethod(String, String, MethodAttributes, CallingConventions, Type, Type[], CallingConvention, CharSet)	Defines a `PInvoke` method with the specified name, the name of the DLL in which the method is defined, the attributes of the method, the calling convention of the method, the return type of the method, the types of the parameters of the method, and the `PInvoke` flags.
DefinePInvokeMethod(String, String, String, MethodAttributes, CallingConventions, Type, Type[], CallingConvention, CharSet)	Defines a `PInvoke` method with the specified name, the name of the DLL in which the method is defined, the attributes of the method, the calling convention of the method, the return type of the method, the types of the parameters of the method, and the `PInvoke` flags.

DefinePInvokeMethod(String, String, MethodAttributes, CallingConventions, Type, Type[], CallingConvention, CharSet)

Source:: ModuleBuilder.cs

Source:: ModuleBuilder.cs

Source:: ModuleBuilder.cs

Defines a PInvoke method with the specified name, the name of the DLL in which the method is defined, the attributes of the method, the calling convention of the method, the return type of the method, the types of the parameters of the method, and the PInvoke flags.

public:
 System::Reflection::Emit::MethodBuilder ^ DefinePInvokeMethod(System::String ^ name, System::String ^ dllName, System::Reflection::MethodAttributes attributes, System::Reflection::CallingConventions callingConvention, Type ^ returnType, cli::array <Type ^> ^ parameterTypes, System::Runtime::InteropServices::CallingConvention nativeCallConv, System::Runtime::InteropServices::CharSet nativeCharSet);

public System.Reflection.Emit.MethodBuilder DefinePInvokeMethod(string name, string dllName, System.Reflection.MethodAttributes attributes, System.Reflection.CallingConventions callingConvention, Type? returnType, Type[]? parameterTypes, System.Runtime.InteropServices.CallingConvention nativeCallConv, System.Runtime.InteropServices.CharSet nativeCharSet);

public System.Reflection.Emit.MethodBuilder DefinePInvokeMethod(string name, string dllName, System.Reflection.MethodAttributes attributes, System.Reflection.CallingConventions callingConvention, Type returnType, Type[] parameterTypes, System.Runtime.InteropServices.CallingConvention nativeCallConv, System.Runtime.InteropServices.CharSet nativeCharSet);

member this.DefinePInvokeMethod : string * string * System.Reflection.MethodAttributes * System.Reflection.CallingConventions * Type * Type[] * System.Runtime.InteropServices.CallingConvention * System.Runtime.InteropServices.CharSet -> System.Reflection.Emit.MethodBuilder

Public Function DefinePInvokeMethod (name As String, dllName As String, attributes As MethodAttributes, callingConvention As CallingConventions, returnType As Type, parameterTypes As Type(), nativeCallConv As CallingConvention, nativeCharSet As CharSet) As MethodBuilder

Parameters

name: String

The name of the PInvoke method. name cannot contain embedded nulls.

dllName: String

The name of the DLL in which the PInvoke method is defined.

attributes: MethodAttributes

The attributes of the method.

callingConvention: CallingConventions

The method's calling convention.

returnType: Type

The method's return type.

parameterTypes: Type[]

The types of the method's parameters.

nativeCallConv: CallingConvention

The native calling convention.

nativeCharSet: CharSet

The method's native character set.

Returns

MethodBuilder

The defined PInvoke method.

Exceptions

ArgumentException

The method is not static or if the containing type is an interface.

-or-

The method is abstract.

-or-

The method was previously defined.

ArgumentNullException

name or dllName is null.

InvalidOperationException

The containing type has been previously created using CreateType()

Examples

The following example illustrates the use of the DefinePInvokeMethod method to create a MethodBuilder for an external unmanaged method, MessageBoxA, in the Windows API. The example displays a message box with Retry and Cancel buttons, and displays the return value from the message box.

Important

To get a non-zero return value, you must add MethodImplAttributes.PreserveSig to the method implementation flags after you create the MethodBuilder, by using the MethodBuilder.GetMethodImplementationFlags and MethodBuilder.SetImplementationFlags methods.

using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
using namespace System::Runtime::InteropServices;

const int MB_RETRYCANCEL = 5;

void main()
{
   AssemblyName^ myAssemblyName = gcnew AssemblyName("TempAssembly");

   // Define a dynamic assembly in the current application domain.
   AssemblyBuilder^ myAssemblyBuilder = 
      AppDomain::CurrentDomain->DefineDynamicAssembly(
                  myAssemblyName, AssemblyBuilderAccess::Run);

   // Define a dynamic module in "TempAssembly" assembly.
   ModuleBuilder^ myModuleBuilder = 
      myAssemblyBuilder->DefineDynamicModule("TempModule");

   array<Type^>^ paramTypes = 
      { int::typeid, String::typeid, String::typeid, int::typeid };

   // Define a PInvoke method.
   MethodBuilder^ piMethodBuilder = myModuleBuilder->DefinePInvokeMethod(
      "MessageBoxA",
      "user32.dll",
      MethodAttributes::Public | MethodAttributes::Static | MethodAttributes::PinvokeImpl,
      CallingConventions::Standard,
      int::typeid,
      paramTypes,
      CallingConvention::Winapi,
      CharSet::Ansi);

   // Add PreserveSig to the method implementation flags. NOTE: If this line
   // is commented out, the return value will be zero when the method is
   // invoked.
   piMethodBuilder->SetImplementationFlags(
      piMethodBuilder->GetMethodImplementationFlags() | MethodImplAttributes::PreserveSig);

   // Create global methods.
   myModuleBuilder->CreateGlobalFunctions();

   // Arguments for calling the method.
   array<Object^>^ arguments = 
      { (Object^)(int) 0, "Hello World", "Title", MB_RETRYCANCEL };

   MethodInfo^ pinvokeMethod = myModuleBuilder->GetMethod("MessageBoxA");
   Console::WriteLine("Testing module-level PInvoke method created with DefinePInvokeMethod...");
   Console::WriteLine("Message box returned: {0}", 
      pinvokeMethod->Invoke(nullptr, arguments));
};


/* This code example produces input similar to the following:

Testing module-level PInvoke method created with DefinePInvokeMethod...
Message box returned: 4
 */

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.InteropServices;

namespace PInvoke
{
   public class Example
   {
      const int MB_RETRYCANCEL = 5;

      static void Main()
      {
         AssemblyName myAssemblyName = new AssemblyName("TempAssembly");

         // Define a dynamic assembly in the current application domain.
         AssemblyBuilder myAssemblyBuilder =
            AppDomain.CurrentDomain.DefineDynamicAssembly(
                        myAssemblyName, AssemblyBuilderAccess.Run);

         // Define a dynamic module in "TempAssembly" assembly.
         ModuleBuilder myModuleBuilder =
            myAssemblyBuilder.DefineDynamicModule("TempModule");

         Type[] paramTypes = { typeof(int), typeof(string), typeof(string), typeof(int) };

         // Define a PInvoke method.
         MethodBuilder piMethodBuilder = myModuleBuilder.DefinePInvokeMethod(
            "MessageBoxA",
            "user32.dll",
            MethodAttributes.Public | MethodAttributes.Static | MethodAttributes.PinvokeImpl,
            CallingConventions.Standard,
            typeof(int),
            paramTypes,
            CallingConvention.Winapi,
            CharSet.Ansi);

         // Add PreserveSig to the method implementation flags. NOTE: If this line
         // is commented out, the return value will be zero when the method is
         // invoked.
         piMethodBuilder.SetImplementationFlags(
            piMethodBuilder.GetMethodImplementationFlags() | MethodImplAttributes.PreserveSig);

         // Create global methods.
         myModuleBuilder.CreateGlobalFunctions();

         // Arguments for calling the method.
         Object[] arguments = { 0, "Hello World", "Title", MB_RETRYCANCEL };

         MethodInfo pinvokeMethod = myModuleBuilder.GetMethod("MessageBoxA");
         Console.WriteLine("Testing module-level PInvoke method created with DefinePInvokeMethod...");
         Console.WriteLine("Message box returned: {0}",
            pinvokeMethod.Invoke(null, arguments));
      }
   }
}

/* This code example produces input similar to the following:

Testing module-level PInvoke method created with DefinePInvokeMethod...
Message box returned: 4
 */

Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Runtime.InteropServices

Namespace PInvoke

   Public Class Example
   
      Const MB_RETRYCANCEL As Integer = 5

      Shared Sub Main()
      
         Dim myAssemblyName As New AssemblyName("TempAssembly")

         ' Define a dynamic assembly in the current application domain.
         Dim myAssemblyBuilder As AssemblyBuilder = _
            AppDomain.CurrentDomain.DefineDynamicAssembly( _
                        myAssemblyName, AssemblyBuilderAccess.Run)

         ' Define a dynamic module in "TempAssembly" assembly.
         Dim myModuleBuilder As ModuleBuilder = _
            myAssemblyBuilder.DefineDynamicModule("TempModule")

         Dim paramTypes() As Type = _
            { GetType(Integer), GetType(string), GetType(string), GetType(Integer) }

         ' Define a PInvoke method.
         Dim piMethodBuilder As MethodBuilder = myModuleBuilder.DefinePInvokeMethod( _
            "MessageBoxA", _
            "user32.dll", _
            MethodAttributes.Public Or MethodAttributes.Static Or MethodAttributes.PinvokeImpl, _
            CallingConventions.Standard, _
            GetType(Integer), _
            paramTypes, _
            CallingConvention.Winapi, _
            CharSet.Ansi)
         
         ' Add PreserveSig to the method implementation flags. NOTE: If this line
         ' is commented out, the return value will be zero when the method is
         ' invoked.
         piMethodBuilder.SetImplementationFlags( _
            piMethodBuilder.GetMethodImplementationFlags() Or MethodImplAttributes.PreserveSig)

         ' Create global methods.
         myModuleBuilder.CreateGlobalFunctions()

         ' Arguments for calling the method.
         Dim arguments() As Object= { 0, "Hello World", "Title", MB_RETRYCANCEL }

         Dim pinvokeMethod As MethodInfo = _
            myModuleBuilder.GetMethod("MessageBoxA")
         Console.WriteLine("Testing module-level PInvoke method created with DefinePInvokeMethod...")
         Console.WriteLine("Message box returned: {0}", _
            pinvokeMethod.Invoke(Nothing, arguments))

      End Sub
   End Class
End Namespace

' This code example produces input similar to the following:
'
'Testing module-level PInvoke method created with DefinePInvokeMethod...
'Message box returned: 4

Remarks

Some DLL import attributes (see the description of System.Runtime.InteropServices.DllImportAttribute) cannot be specified as arguments to this method. Such attributes should be set by emitting a custom attribute for the method. For example, the DLL import attribute PreserveSig is set by emitting a custom attribute.

Note

Starting with the .NET Framework 2.0 Service Pack 1, this member no longer requires ReflectionPermission with the ReflectionPermissionFlag.ReflectionEmit flag. (See Security Issues in Reflection Emit.) To use this functionality, your application should target the .NET Framework 3.5 or later.

Applies to

.NET 10 and other versions

Product	Versions
.NET	Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.1

DefinePInvokeMethod(String, String, String, MethodAttributes, CallingConventions, Type, Type[], CallingConvention, CharSet)

Source:: ModuleBuilder.cs

Source:: ModuleBuilder.cs

Source:: ModuleBuilder.cs

public:
 System::Reflection::Emit::MethodBuilder ^ DefinePInvokeMethod(System::String ^ name, System::String ^ dllName, System::String ^ entryName, System::Reflection::MethodAttributes attributes, System::Reflection::CallingConventions callingConvention, Type ^ returnType, cli::array <Type ^> ^ parameterTypes, System::Runtime::InteropServices::CallingConvention nativeCallConv, System::Runtime::InteropServices::CharSet nativeCharSet);

public System.Reflection.Emit.MethodBuilder DefinePInvokeMethod(string name, string dllName, string entryName, System.Reflection.MethodAttributes attributes, System.Reflection.CallingConventions callingConvention, Type? returnType, Type[]? parameterTypes, System.Runtime.InteropServices.CallingConvention nativeCallConv, System.Runtime.InteropServices.CharSet nativeCharSet);

public System.Reflection.Emit.MethodBuilder DefinePInvokeMethod(string name, string dllName, string entryName, System.Reflection.MethodAttributes attributes, System.Reflection.CallingConventions callingConvention, Type returnType, Type[] parameterTypes, System.Runtime.InteropServices.CallingConvention nativeCallConv, System.Runtime.InteropServices.CharSet nativeCharSet);

member this.DefinePInvokeMethod : string * string * string * System.Reflection.MethodAttributes * System.Reflection.CallingConventions * Type * Type[] * System.Runtime.InteropServices.CallingConvention * System.Runtime.InteropServices.CharSet -> System.Reflection.Emit.MethodBuilder

Public Function DefinePInvokeMethod (name As String, dllName As String, entryName As String, attributes As MethodAttributes, callingConvention As CallingConventions, returnType As Type, parameterTypes As Type(), nativeCallConv As CallingConvention, nativeCharSet As CharSet) As MethodBuilder

Parameters

name: String

The name of the PInvoke method. name cannot contain embedded nulls.

dllName: String

The name of the DLL in which the PInvoke method is defined.

entryName: String

The name of the entry point in the DLL.

attributes: MethodAttributes

The attributes of the method.

callingConvention: CallingConventions

The method's calling convention.

returnType: Type

The method's return type.

parameterTypes: Type[]

The types of the method's parameters.

nativeCallConv: CallingConvention

The native calling convention.

nativeCharSet: CharSet

The method's native character set.

Returns

MethodBuilder

The defined PInvoke method.

Exceptions

ArgumentException

The method is not static or if the containing type is an interface or if the method is abstract of if the method was previously defined.

ArgumentNullException

name or dllName is null.

InvalidOperationException

The containing type has been previously created using CreateType()

Examples

Important

This example uses a different overload of the DefinePInvokeMethod method, but the technique is the same.

using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
using namespace System::Runtime::InteropServices;

const int MB_RETRYCANCEL = 5;

void main()
{
   AssemblyName^ myAssemblyName = gcnew AssemblyName("TempAssembly");

   // Define a dynamic assembly in the current application domain.
   AssemblyBuilder^ myAssemblyBuilder = 
      AppDomain::CurrentDomain->DefineDynamicAssembly(
                  myAssemblyName, AssemblyBuilderAccess::Run);

   // Define a dynamic module in "TempAssembly" assembly.
   ModuleBuilder^ myModuleBuilder = 
      myAssemblyBuilder->DefineDynamicModule("TempModule");

   array<Type^>^ paramTypes = 
      { int::typeid, String::typeid, String::typeid, int::typeid };

   // Define a PInvoke method.
   MethodBuilder^ piMethodBuilder = myModuleBuilder->DefinePInvokeMethod(
      "MessageBoxA",
      "user32.dll",
      MethodAttributes::Public | MethodAttributes::Static | MethodAttributes::PinvokeImpl,
      CallingConventions::Standard,
      int::typeid,
      paramTypes,
      CallingConvention::Winapi,
      CharSet::Ansi);

   // Add PreserveSig to the method implementation flags. NOTE: If this line
   // is commented out, the return value will be zero when the method is
   // invoked.
   piMethodBuilder->SetImplementationFlags(
      piMethodBuilder->GetMethodImplementationFlags() | MethodImplAttributes::PreserveSig);

   // Create global methods.
   myModuleBuilder->CreateGlobalFunctions();

   // Arguments for calling the method.
   array<Object^>^ arguments = 
      { (Object^)(int) 0, "Hello World", "Title", MB_RETRYCANCEL };

   MethodInfo^ pinvokeMethod = myModuleBuilder->GetMethod("MessageBoxA");
   Console::WriteLine("Testing module-level PInvoke method created with DefinePInvokeMethod...");
   Console::WriteLine("Message box returned: {0}", 
      pinvokeMethod->Invoke(nullptr, arguments));
};


/* This code example produces input similar to the following:

Testing module-level PInvoke method created with DefinePInvokeMethod...
Message box returned: 4
 */

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.InteropServices;

namespace PInvoke
{
   public class Example
   {
      const int MB_RETRYCANCEL = 5;

      static void Main()
      {
         AssemblyName myAssemblyName = new AssemblyName("TempAssembly");

         // Define a dynamic assembly in the current application domain.
         AssemblyBuilder myAssemblyBuilder =
            AppDomain.CurrentDomain.DefineDynamicAssembly(
                        myAssemblyName, AssemblyBuilderAccess.Run);

         // Define a dynamic module in "TempAssembly" assembly.
         ModuleBuilder myModuleBuilder =
            myAssemblyBuilder.DefineDynamicModule("TempModule");

         Type[] paramTypes = { typeof(int), typeof(string), typeof(string), typeof(int) };

         // Define a PInvoke method.
         MethodBuilder piMethodBuilder = myModuleBuilder.DefinePInvokeMethod(
            "MessageBoxA",
            "user32.dll",
            MethodAttributes.Public | MethodAttributes.Static | MethodAttributes.PinvokeImpl,
            CallingConventions.Standard,
            typeof(int),
            paramTypes,
            CallingConvention.Winapi,
            CharSet.Ansi);

         // Add PreserveSig to the method implementation flags. NOTE: If this line
         // is commented out, the return value will be zero when the method is
         // invoked.
         piMethodBuilder.SetImplementationFlags(
            piMethodBuilder.GetMethodImplementationFlags() | MethodImplAttributes.PreserveSig);

         // Create global methods.
         myModuleBuilder.CreateGlobalFunctions();

         // Arguments for calling the method.
         Object[] arguments = { 0, "Hello World", "Title", MB_RETRYCANCEL };

         MethodInfo pinvokeMethod = myModuleBuilder.GetMethod("MessageBoxA");
         Console.WriteLine("Testing module-level PInvoke method created with DefinePInvokeMethod...");
         Console.WriteLine("Message box returned: {0}",
            pinvokeMethod.Invoke(null, arguments));
      }
   }
}

/* This code example produces input similar to the following:

Testing module-level PInvoke method created with DefinePInvokeMethod...
Message box returned: 4
 */

Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Runtime.InteropServices

Namespace PInvoke

   Public Class Example
   
      Const MB_RETRYCANCEL As Integer = 5

      Shared Sub Main()
      
         Dim myAssemblyName As New AssemblyName("TempAssembly")

         ' Define a dynamic assembly in the current application domain.
         Dim myAssemblyBuilder As AssemblyBuilder = _
            AppDomain.CurrentDomain.DefineDynamicAssembly( _
                        myAssemblyName, AssemblyBuilderAccess.Run)

         ' Define a dynamic module in "TempAssembly" assembly.
         Dim myModuleBuilder As ModuleBuilder = _
            myAssemblyBuilder.DefineDynamicModule("TempModule")

         Dim paramTypes() As Type = _
            { GetType(Integer), GetType(string), GetType(string), GetType(Integer) }

         ' Define a PInvoke method.
         Dim piMethodBuilder As MethodBuilder = myModuleBuilder.DefinePInvokeMethod( _
            "MessageBoxA", _
            "user32.dll", _
            MethodAttributes.Public Or MethodAttributes.Static Or MethodAttributes.PinvokeImpl, _
            CallingConventions.Standard, _
            GetType(Integer), _
            paramTypes, _
            CallingConvention.Winapi, _
            CharSet.Ansi)
         
         ' Add PreserveSig to the method implementation flags. NOTE: If this line
         ' is commented out, the return value will be zero when the method is
         ' invoked.
         piMethodBuilder.SetImplementationFlags( _
            piMethodBuilder.GetMethodImplementationFlags() Or MethodImplAttributes.PreserveSig)

         ' Create global methods.
         myModuleBuilder.CreateGlobalFunctions()

         ' Arguments for calling the method.
         Dim arguments() As Object= { 0, "Hello World", "Title", MB_RETRYCANCEL }

         Dim pinvokeMethod As MethodInfo = _
            myModuleBuilder.GetMethod("MessageBoxA")
         Console.WriteLine("Testing module-level PInvoke method created with DefinePInvokeMethod...")
         Console.WriteLine("Message box returned: {0}", _
            pinvokeMethod.Invoke(Nothing, arguments))

      End Sub
   End Class
End Namespace

' This code example produces input similar to the following:
'
'Testing module-level PInvoke method created with DefinePInvokeMethod...
'Message box returned: 4

Remarks

Some DLL import attributes (see the description of DllImportAttribute) cannot be specified as arguments to this method. Such attributes should be set by emitting a custom attribute for the method. For example, the DLL import attribute PreserveSig is set by emitting a custom attribute.

Note

Applies to

.NET 10 and other versions

Product	Versions
.NET	Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	2.1

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ModuleBuilder.DefinePInvokeMethod Method

Definition

Overloads

DefinePInvokeMethod(String, String, MethodAttributes, CallingConventions, Type, Type[], CallingConvention, CharSet)

Parameters

Returns

Exceptions

Examples

Remarks

Applies to

DefinePInvokeMethod(String, String, String, MethodAttributes, CallingConventions, Type, Type[], CallingConvention, CharSet)

Parameters

Returns

Exceptions

Examples

Remarks

Applies to

Additional resources