TypeBuilder.DefinePInvokeMethod TypeBuilder.DefinePInvokeMethod TypeBuilder.DefinePInvokeMethod Method

Definition

Defines a PInvoke method.

Overloads

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

Defines a PInvoke method given its 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) DefinePInvokeMethod(String, String, String, MethodAttributes, CallingConventions, Type, Type[], CallingConvention, CharSet) DefinePInvokeMethod(String, String, String, MethodAttributes, CallingConventions, Type, Type[], CallingConvention, CharSet)

Defines a PInvoke method given its name, the name of the DLL in which the method is defined, the name of the entry point, 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, Type[][], CallingConvention, CharSet, String, MethodAttributes, CallingConventions, Type, Type[], Type[], Type[], Type[][]) DefinePInvokeMethod(String, String, Type[][], CallingConvention, CharSet, String, MethodAttributes, CallingConventions, Type, Type[], Type[], Type[], Type[][]) DefinePInvokeMethod(String, String, Type[][], CallingConvention, CharSet, String, MethodAttributes, CallingConventions, Type, Type[], Type[], Type[], Type[][])

Defines a PInvoke method given its name, the name of the DLL in which the method is defined, the name of the entry point, 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, the PInvoke flags, and custom modifiers for the parameters and return type.

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

Defines a PInvoke method given its 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);
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

Parameters

name
String String String

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

dllName
String String String

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

attributes
MethodAttributes MethodAttributes MethodAttributes

The attributes of the method.

callingConvention
CallingConventions CallingConventions CallingConventions

The method's calling convention.

returnType
Type Type Type

The method's return type.

parameterTypes
Type[]

The types of the method's parameters.

nativeCallConv
CallingConvention CallingConvention CallingConvention

The native calling convention.

nativeCharSet
CharSet CharSet CharSet

The method's native character set.

Returns

The defined PInvoke method.

Exceptions

The method is not static.

-or-

The parent type is an interface.

-or-

The method is abstract.

-or-

The method was previously defined.

-or-

The length of name or dllName is zero.

The containing type has been previously created using CreateType().

Examples

The following example demonstrates how to use the DefinePInvokeMethod method to create a PInvoke method, and how to add the MethodImplAttributes.PreserveSig flag to the method implementation flags after you create the MethodBuilder, by using the MethodBuilder.GetMethodImplementationFlags and MethodBuilder.SetImplementationFlags methods.

Important

To get a non-zero return value, you must add the MethodImplAttributes.PreserveSig flag.

The example creates a dynamic assembly with one dynamic module and a single type, MyType, that contains the PInvoke method. The PInvoke method represents the Win32 GetTickCount function.

When the example is run, it executes the PInvoke method. It also saves the dynamic assembly as PInvokeTest.dll. You can use the Ildasm.exe (IL Disassembler) to examine the MyType class and the static (Shared in Visual Basic) PInvoke method it contains. You can compile a Visual Basic or C# program that uses the static MyType.GetTickCount method by including a reference to the DLL when you run csc.exe or vbc.exe; for example, /r:PInvokeTest.dll.

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

    void main()
    {
        // Create the AssemblyBuilder.
        AssemblyName^ asmName = gcnew AssemblyName("PInvokeTest");
        AssemblyBuilder^ dynamicAsm = AppDomain::CurrentDomain->DefineDynamicAssembly(
            asmName, 
            AssemblyBuilderAccess::RunAndSave
        );

        // Create the module.
        ModuleBuilder^ dynamicMod = 
            dynamicAsm->DefineDynamicModule(asmName->Name, asmName->Name + ".dll");

        // Create the TypeBuilder for the class that will contain the 
        // signature for the PInvoke call.
        TypeBuilder^ tb = dynamicMod->DefineType(
            "MyType", 
            TypeAttributes::Public | TypeAttributes::UnicodeClass
        );
    
        MethodBuilder^ mb = tb->DefinePInvokeMethod(
            "GetTickCount",
            "Kernel32.dll",
            MethodAttributes::Public | MethodAttributes::Static | MethodAttributes::PinvokeImpl,
            CallingConventions::Standard,
            int::typeid,
            Type::EmptyTypes,
            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.
        mb->SetImplementationFlags(
            mb->GetMethodImplementationFlags() | MethodImplAttributes::PreserveSig);

        // The PInvoke method does not have a method body. 

        // Create the class and test the method.
        Type^ t = tb->CreateType();

        MethodInfo^ mi = t->GetMethod("GetTickCount");
        Console::WriteLine("Testing PInvoke method...");
        Console::WriteLine("GetTickCount returned: {0}", mi->Invoke(nullptr, nullptr));

        // Produce the .dll file.
        Console::WriteLine("Saving: " + asmName->Name + ".dll");
        dynamicAsm->Save(asmName->Name + ".dll");
    };

/* This example produces output similar to the following:

Testing PInvoke method...
GetTickCount returned: 1314410994
Saving: PInvokeTest.dll
 */
using System;
using System.Text;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.InteropServices;

public class Example
{
    public static void Main()
    {
        // Create the AssemblyBuilder.
        AssemblyName asmName = new AssemblyName("PInvokeTest");           
        AssemblyBuilder dynamicAsm = AppDomain.CurrentDomain.DefineDynamicAssembly(
            asmName, 
            AssemblyBuilderAccess.RunAndSave
        );

        // Create the module.
        ModuleBuilder dynamicMod = 
            dynamicAsm.DefineDynamicModule(asmName.Name, asmName.Name + ".dll");

        // Create the TypeBuilder for the class that will contain the 
        // signature for the PInvoke call.
        TypeBuilder tb = dynamicMod.DefineType(
            "MyType", 
            TypeAttributes.Public | TypeAttributes.UnicodeClass
        );
    
        MethodBuilder mb = tb.DefinePInvokeMethod(
            "GetTickCount",
            "Kernel32.dll",
            MethodAttributes.Public | MethodAttributes.Static | MethodAttributes.PinvokeImpl,
            CallingConventions.Standard,
            typeof(int),
            Type.EmptyTypes,
            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.
        mb.SetImplementationFlags(
            mb.GetMethodImplementationFlags() | MethodImplAttributes.PreserveSig);

        // The PInvoke method does not have a method body. 

        // Create the class and test the method.
        Type t = tb.CreateType();

        MethodInfo mi = t.GetMethod("GetTickCount");
        Console.WriteLine("Testing PInvoke method...");
        Console.WriteLine("GetTickCount returned: {0}", mi.Invoke(null, null));

        // Produce the .dll file.
        Console.WriteLine("Saving: " + asmName.Name + ".dll");
        dynamicAsm.Save(asmName.Name + ".dll");
    }
}

/* This example produces output similar to the following:

Testing PInvoke method...
GetTickCount returned: 1312576235
Saving: PInvokeTest.dll
 */
Imports System
Imports System.Text
Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Runtime.InteropServices

Public Class Example
    
    Public Shared Sub Main() 
        
        ' Create the AssemblyBuilder.
        Dim asmName As New AssemblyName("PInvokeTest")
        Dim dynamicAsm As AssemblyBuilder = _
            AppDomain.CurrentDomain.DefineDynamicAssembly(asmName, _
                AssemblyBuilderAccess.RunAndSave)
        
        ' Create the module.
        Dim dynamicMod As ModuleBuilder = _
            dynamicAsm.DefineDynamicModule(asmName.Name, asmName.Name & ".dll")
        
        ' Create the TypeBuilder for the class that will contain the 
        ' signature for the PInvoke call.
        Dim tb As TypeBuilder = dynamicMod.DefineType("MyType", _
            TypeAttributes.Public Or TypeAttributes.UnicodeClass)
        
        Dim mb As MethodBuilder = tb.DefinePInvokeMethod( _
            "GetTickCount", _
            "Kernel32.dll", _
            MethodAttributes.Public Or MethodAttributes.Static Or MethodAttributes.PinvokeImpl, _
            CallingConventions.Standard, _
            GetType(Integer), _
            Type.EmptyTypes, _
            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.
        mb.SetImplementationFlags( _
            mb.GetMethodImplementationFlags() Or MethodImplAttributes.PreserveSig)
        
        ' The PInvoke method does not have a method body.
        
        ' Create the class and test the method.
        Dim t As Type = tb.CreateType()

        Dim mi As MethodInfo = t.GetMethod("GetTickCount")
        Console.WriteLine("Testing PInvoke method...")
        Console.WriteLine("GetTickCount returned: {0}", mi.Invoke(Nothing, Nothing))

        ' Produce the .dll file.
        Console.WriteLine("Saving: " & asmName.Name & ".dll")
        dynamicAsm.Save(asmName.Name & ".dll")
    
    End Sub  
End Class 

' This example produces output similar to the following:
'
'Testing PInvoke method...
'GetTickCount returned: 1313078714
'Saving: PInvokeTest.dll

Remarks

Some DLL import attributes (see the description of DllImportAttribute) cannot be specified as arguments to this method. For example, the DLL import attribute MethodImplAttributes.PreserveSig must be added after the PInvoke method is created, if the method returns a value. The example shows how to do this.

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

Defines a PInvoke method given its name, the name of the DLL in which the method is defined, the name of the entry point, 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::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);
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

Parameters

name
String String String

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

dllName
String String String

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

entryName
String String String

The name of the entry point in the DLL.

attributes
MethodAttributes MethodAttributes MethodAttributes

The attributes of the method.

callingConvention
CallingConventions CallingConventions CallingConventions

The method's calling convention.

returnType
Type Type Type

The method's return type.

parameterTypes
Type[]

The types of the method's parameters.

nativeCallConv
CallingConvention CallingConvention CallingConvention

The native calling convention.

nativeCharSet
CharSet CharSet CharSet

The method's native character set.

Returns

The defined PInvoke method.

Exceptions

The method is not static.

-or-

The parent type is an interface.

-or-

The method is abstract.

-or-

The method was previously defined.

-or-

The length of name, dllName, or entryName is zero.

The containing type has been previously created using CreateType().

Examples

The following code example demonstrates how to use the DefinePInvokeMethod method to create a PInvoke method, and how to add the MethodImplAttributes.PreserveSig flag to the method implementation flags after you create the MethodBuilder, by using the MethodBuilder.GetMethodImplementationFlags and MethodBuilder.SetImplementationFlags methods.

Important

To get a non-zero return value, you must add the MethodImplAttributes.PreserveSig flag.

The example creates a dynamic assembly with one dynamic module and a single type, MyType, that contains the PInvoke method. The PInvoke method represents the Win32 GetTickCount function.

When the example is run, it executes the PInvoke method. It also saves the dynamic assembly as PInvokeTest.dll. You can use the Ildasm.exe (IL Disassembler) to examine the MyType class and the static (Shared in Visual Basic) PInvoke method it contains. You can compile a Visual Basic or C# program that uses the static MyType.GetTickCount method by including a reference to the DLL when you run csc.exe or vbc.exe; for example, /r:PInvokeTest.dll.

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

    void main()
    {
        // Create the AssemblyBuilder.
        AssemblyName^ asmName = gcnew AssemblyName("PInvokeTest");
        AssemblyBuilder^ dynamicAsm = AppDomain::CurrentDomain->DefineDynamicAssembly(
            asmName, 
            AssemblyBuilderAccess::RunAndSave
        );

        // Create the module.
        ModuleBuilder^ dynamicMod = 
            dynamicAsm->DefineDynamicModule(asmName->Name, asmName->Name + ".dll");

        // Create the TypeBuilder for the class that will contain the 
        // signature for the PInvoke call.
        TypeBuilder^ tb = dynamicMod->DefineType(
            "MyType", 
            TypeAttributes::Public | TypeAttributes::UnicodeClass
        );
    
        MethodBuilder^ mb = tb->DefinePInvokeMethod(
            "GetTickCount",
            "Kernel32.dll",
            MethodAttributes::Public | MethodAttributes::Static | MethodAttributes::PinvokeImpl,
            CallingConventions::Standard,
            int::typeid,
            Type::EmptyTypes,
            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.
        mb->SetImplementationFlags(
            mb->GetMethodImplementationFlags() | MethodImplAttributes::PreserveSig);

        // The PInvoke method does not have a method body. 

        // Create the class and test the method.
        Type^ t = tb->CreateType();

        MethodInfo^ mi = t->GetMethod("GetTickCount");
        Console::WriteLine("Testing PInvoke method...");
        Console::WriteLine("GetTickCount returned: {0}", mi->Invoke(nullptr, nullptr));

        // Produce the .dll file.
        Console::WriteLine("Saving: " + asmName->Name + ".dll");
        dynamicAsm->Save(asmName->Name + ".dll");
    };

/* This example produces output similar to the following:

Testing PInvoke method...
GetTickCount returned: 1314410994
Saving: PInvokeTest.dll
 */
using System;
using System.Text;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.InteropServices;

public class Example
{
    public static void Main()
    {
        // Create the AssemblyBuilder.
        AssemblyName asmName = new AssemblyName("PInvokeTest");           
        AssemblyBuilder dynamicAsm = AppDomain.CurrentDomain.DefineDynamicAssembly(
            asmName, 
            AssemblyBuilderAccess.RunAndSave
        );

        // Create the module.
        ModuleBuilder dynamicMod = 
            dynamicAsm.DefineDynamicModule(asmName.Name, asmName.Name + ".dll");

        // Create the TypeBuilder for the class that will contain the 
        // signature for the PInvoke call.
        TypeBuilder tb = dynamicMod.DefineType(
            "MyType", 
            TypeAttributes.Public | TypeAttributes.UnicodeClass
        );
    
        MethodBuilder mb = tb.DefinePInvokeMethod(
            "GetTickCount",
            "Kernel32.dll",
            MethodAttributes.Public | MethodAttributes.Static | MethodAttributes.PinvokeImpl,
            CallingConventions.Standard,
            typeof(int),
            Type.EmptyTypes,
            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.
        mb.SetImplementationFlags(
            mb.GetMethodImplementationFlags() | MethodImplAttributes.PreserveSig);

        // The PInvoke method does not have a method body. 

        // Create the class and test the method.
        Type t = tb.CreateType();

        MethodInfo mi = t.GetMethod("GetTickCount");
        Console.WriteLine("Testing PInvoke method...");
        Console.WriteLine("GetTickCount returned: {0}", mi.Invoke(null, null));

        // Produce the .dll file.
        Console.WriteLine("Saving: " + asmName.Name + ".dll");
        dynamicAsm.Save(asmName.Name + ".dll");
    }
}

/* This example produces output similar to the following:

Testing PInvoke method...
GetTickCount returned: 1312576235
Saving: PInvokeTest.dll
 */
Imports System
Imports System.Text
Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Runtime.InteropServices

Public Class Example
    
    Public Shared Sub Main() 
        
        ' Create the AssemblyBuilder.
        Dim asmName As New AssemblyName("PInvokeTest")
        Dim dynamicAsm As AssemblyBuilder = _
            AppDomain.CurrentDomain.DefineDynamicAssembly(asmName, _
                AssemblyBuilderAccess.RunAndSave)
        
        ' Create the module.
        Dim dynamicMod As ModuleBuilder = _
            dynamicAsm.DefineDynamicModule(asmName.Name, asmName.Name & ".dll")
        
        ' Create the TypeBuilder for the class that will contain the 
        ' signature for the PInvoke call.
        Dim tb As TypeBuilder = dynamicMod.DefineType("MyType", _
            TypeAttributes.Public Or TypeAttributes.UnicodeClass)
        
        Dim mb As MethodBuilder = tb.DefinePInvokeMethod( _
            "GetTickCount", _
            "Kernel32.dll", _
            MethodAttributes.Public Or MethodAttributes.Static Or MethodAttributes.PinvokeImpl, _
            CallingConventions.Standard, _
            GetType(Integer), _
            Type.EmptyTypes, _
            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.
        mb.SetImplementationFlags( _
            mb.GetMethodImplementationFlags() Or MethodImplAttributes.PreserveSig)
        
        ' The PInvoke method does not have a method body.
        
        ' Create the class and test the method.
        Dim t As Type = tb.CreateType()

        Dim mi As MethodInfo = t.GetMethod("GetTickCount")
        Console.WriteLine("Testing PInvoke method...")
        Console.WriteLine("GetTickCount returned: {0}", mi.Invoke(Nothing, Nothing))

        ' Produce the .dll file.
        Console.WriteLine("Saving: " & asmName.Name & ".dll")
        dynamicAsm.Save(asmName.Name & ".dll")
    
    End Sub  
End Class 

' This example produces output similar to the following:
'
'Testing PInvoke method...
'GetTickCount returned: 1313078714
'Saving: PInvokeTest.dll

Remarks

Some DLL import attributes (see the description of DllImportAttribute) cannot be specified as arguments to this method. For example, the DLL import attribute MethodImplAttributes.PreserveSig must be added after the PInvoke method is created, if the method returns a value. The example shows how to do this.

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

Defines a PInvoke method given its name, the name of the DLL in which the method is defined, the name of the entry point, 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, the PInvoke flags, and custom modifiers for the parameters and return type.

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 ^> ^ returnTypeRequiredCustomModifiers, cli::array <Type ^> ^ returnTypeOptionalCustomModifiers, cli::array <Type ^> ^ parameterTypes, cli::array <cli::array <Type ^> ^> ^ parameterTypeRequiredCustomModifiers, cli::array <cli::array <Type ^> ^> ^ parameterTypeOptionalCustomModifiers, 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[] returnTypeRequiredCustomModifiers, Type[] returnTypeOptionalCustomModifiers, Type[] parameterTypes, Type[][] parameterTypeRequiredCustomModifiers, Type[][] parameterTypeOptionalCustomModifiers, System.Runtime.InteropServices.CallingConvention nativeCallConv, System.Runtime.InteropServices.CharSet nativeCharSet);
member this.DefinePInvokeMethod : string * string * string * System.Reflection.MethodAttributes * System.Reflection.CallingConventions * Type * Type[] * Type[] * Type[] * Type[][] * Type[][] * System.Runtime.InteropServices.CallingConvention * System.Runtime.InteropServices.CharSet -> System.Reflection.Emit.MethodBuilder

Parameters

name
String String String

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

dllName
String String String

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

parameterTypeOptionalCustomModifiers
Type[][]

An array of arrays of types. Each array of types represents the optional custom modifiers for the corresponding parameter, such as IsConst. If a particular parameter has no optional custom modifiers, specify null instead of an array of types. If none of the parameters have optional custom modifiers, specify null instead of an array of arrays.

nativeCallConv
CallingConvention CallingConvention CallingConvention

The native calling convention.

nativeCharSet
CharSet CharSet CharSet

The method's native character set.

entryName
String String String

The name of the entry point in the DLL.

attributes
MethodAttributes MethodAttributes MethodAttributes

The attributes of the method.

callingConvention
CallingConventions CallingConventions CallingConventions

The method's calling convention.

returnType
Type Type Type

The method's return type.

returnTypeRequiredCustomModifiers
Type[]

An array of types representing the required custom modifiers, such as IsConst, for the return type of the method. If the return type has no required custom modifiers, specify null.

returnTypeOptionalCustomModifiers
Type[]

An array of types representing the optional custom modifiers, such as IsConst, for the return type of the method. If the return type has no optional custom modifiers, specify null.

parameterTypes
Type[]

The types of the method's parameters.

parameterTypeRequiredCustomModifiers
Type[][]

An array of arrays of types. Each array of types represents the required custom modifiers for the corresponding parameter, such as IsConst. If a particular parameter has no required custom modifiers, specify null instead of an array of types. If none of the parameters have required custom modifiers, specify null instead of an array of arrays.

Returns

A MethodBuilder representing the defined PInvoke method.

Exceptions

The method is not static.

-or-

The parent type is an interface.

-or-

The method is abstract.

-or-

The method was previously defined.

-or-

The length of name, dllName, or entryName is zero.

-or-

The size of parameterTypeRequiredCustomModifiers or parameterTypeOptionalCustomModifiers does not equal the size of parameterTypes.

The type was previously created using CreateType().

-or-

For the current dynamic type, the IsGenericType property is true, but the IsGenericTypeDefinition property is false.

Examples

The following code example demonstrates how to use the [], Type[], Type[], Type[][], Type[]<xref:System.Reflection.Emit.TypeBuilder.DefinePInvokeMethod%2A> method to create a PInvoke method, and how to add the MethodImplAttributes.PreserveSig flag to the method implementation flags after you create the MethodBuilder, by using the MethodBuilder.GetMethodImplementationFlags and MethodBuilder.SetImplementationFlags methods.

The example creates a dynamic assembly with one dynamic module and a single type, MyType, that contains the PInvoke method. The PInvoke method represents the Win32 GetTickCount function.

Important

To get a non-zero return value, you must add the MethodImplAttributes.PreserveSig flag.

Note

The example uses an overload that does not specify custom modifiers. To specify custom modifiers, change the example code to use this method overload instead.

When the example is run, it executes the PInvoke method. It also saves the dynamic assembly as PInvokeTest.dll. You can use the Ildasm.exe (IL Disassembler) to examine the MyType class and the static (Shared in Visual Basic) PInvoke method it contains. You can compile a Visual Basic or C# program that uses the static MyType.GetTickCount method by including a reference to the DLL when you run csc.exe or vbc.exe; for example, /r:PInvokeTest.dll.

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

    void main()
    {
        // Create the AssemblyBuilder.
        AssemblyName^ asmName = gcnew AssemblyName("PInvokeTest");
        AssemblyBuilder^ dynamicAsm = AppDomain::CurrentDomain->DefineDynamicAssembly(
            asmName, 
            AssemblyBuilderAccess::RunAndSave
        );

        // Create the module.
        ModuleBuilder^ dynamicMod = 
            dynamicAsm->DefineDynamicModule(asmName->Name, asmName->Name + ".dll");

        // Create the TypeBuilder for the class that will contain the 
        // signature for the PInvoke call.
        TypeBuilder^ tb = dynamicMod->DefineType(
            "MyType", 
            TypeAttributes::Public | TypeAttributes::UnicodeClass
        );
    
        MethodBuilder^ mb = tb->DefinePInvokeMethod(
            "GetTickCount",
            "Kernel32.dll",
            MethodAttributes::Public | MethodAttributes::Static | MethodAttributes::PinvokeImpl,
            CallingConventions::Standard,
            int::typeid,
            Type::EmptyTypes,
            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.
        mb->SetImplementationFlags(
            mb->GetMethodImplementationFlags() | MethodImplAttributes::PreserveSig);

        // The PInvoke method does not have a method body. 

        // Create the class and test the method.
        Type^ t = tb->CreateType();

        MethodInfo^ mi = t->GetMethod("GetTickCount");
        Console::WriteLine("Testing PInvoke method...");
        Console::WriteLine("GetTickCount returned: {0}", mi->Invoke(nullptr, nullptr));

        // Produce the .dll file.
        Console::WriteLine("Saving: " + asmName->Name + ".dll");
        dynamicAsm->Save(asmName->Name + ".dll");
    };

/* This example produces output similar to the following:

Testing PInvoke method...
GetTickCount returned: 1314410994
Saving: PInvokeTest.dll
 */
using System;
using System.Text;
using System.Reflection;
using System.Reflection.Emit;
using System.Runtime.InteropServices;

public class Example
{
    public static void Main()
    {
        // Create the AssemblyBuilder.
        AssemblyName asmName = new AssemblyName("PInvokeTest");           
        AssemblyBuilder dynamicAsm = AppDomain.CurrentDomain.DefineDynamicAssembly(
            asmName, 
            AssemblyBuilderAccess.RunAndSave
        );

        // Create the module.
        ModuleBuilder dynamicMod = 
            dynamicAsm.DefineDynamicModule(asmName.Name, asmName.Name + ".dll");

        // Create the TypeBuilder for the class that will contain the 
        // signature for the PInvoke call.
        TypeBuilder tb = dynamicMod.DefineType(
            "MyType", 
            TypeAttributes.Public | TypeAttributes.UnicodeClass
        );
    
        MethodBuilder mb = tb.DefinePInvokeMethod(
            "GetTickCount",
            "Kernel32.dll",
            MethodAttributes.Public | MethodAttributes.Static | MethodAttributes.PinvokeImpl,
            CallingConventions.Standard,
            typeof(int),
            Type.EmptyTypes,
            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.
        mb.SetImplementationFlags(
            mb.GetMethodImplementationFlags() | MethodImplAttributes.PreserveSig);

        // The PInvoke method does not have a method body. 

        // Create the class and test the method.
        Type t = tb.CreateType();

        MethodInfo mi = t.GetMethod("GetTickCount");
        Console.WriteLine("Testing PInvoke method...");
        Console.WriteLine("GetTickCount returned: {0}", mi.Invoke(null, null));

        // Produce the .dll file.
        Console.WriteLine("Saving: " + asmName.Name + ".dll");
        dynamicAsm.Save(asmName.Name + ".dll");
    }
}

/* This example produces output similar to the following:

Testing PInvoke method...
GetTickCount returned: 1312576235
Saving: PInvokeTest.dll
 */
Imports System
Imports System.Text
Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Runtime.InteropServices

Public Class Example
    
    Public Shared Sub Main() 
        
        ' Create the AssemblyBuilder.
        Dim asmName As New AssemblyName("PInvokeTest")
        Dim dynamicAsm As AssemblyBuilder = _
            AppDomain.CurrentDomain.DefineDynamicAssembly(asmName, _
                AssemblyBuilderAccess.RunAndSave)
        
        ' Create the module.
        Dim dynamicMod As ModuleBuilder = _
            dynamicAsm.DefineDynamicModule(asmName.Name, asmName.Name & ".dll")
        
        ' Create the TypeBuilder for the class that will contain the 
        ' signature for the PInvoke call.
        Dim tb As TypeBuilder = dynamicMod.DefineType("MyType", _
            TypeAttributes.Public Or TypeAttributes.UnicodeClass)
        
        Dim mb As MethodBuilder = tb.DefinePInvokeMethod( _
            "GetTickCount", _
            "Kernel32.dll", _
            MethodAttributes.Public Or MethodAttributes.Static Or MethodAttributes.PinvokeImpl, _
            CallingConventions.Standard, _
            GetType(Integer), _
            Type.EmptyTypes, _
            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.
        mb.SetImplementationFlags( _
            mb.GetMethodImplementationFlags() Or MethodImplAttributes.PreserveSig)
        
        ' The PInvoke method does not have a method body.
        
        ' Create the class and test the method.
        Dim t As Type = tb.CreateType()

        Dim mi As MethodInfo = t.GetMethod("GetTickCount")
        Console.WriteLine("Testing PInvoke method...")
        Console.WriteLine("GetTickCount returned: {0}", mi.Invoke(Nothing, Nothing))

        ' Produce the .dll file.
        Console.WriteLine("Saving: " & asmName.Name & ".dll")
        dynamicAsm.Save(asmName.Name & ".dll")
    
    End Sub  
End Class 

' This example produces output similar to the following:
'
'Testing PInvoke method...
'GetTickCount returned: 1313078714
'Saving: PInvokeTest.dll

Remarks

Some DLL import attributes (see the description of DllImportAttribute) cannot be specified as arguments to this method. For example, the DLL import attribute MethodImplAttributes.PreserveSig must be added after the PInvoke method is created, if the method returns a value. The example shows how to do this.

Note

For more information on custom modifiers, see the ECMA Partition II Metadata documentation. The documentation is available online; see ECMA C# and Common Language Infrastructure Standards on MSDN and Standard ECMA-335 - Common Language Infrastructure (CLI) on the Ecma International Web site.

Applies to