FieldBuilder.SetOffset(Int32) Method

Reference

Definition

Namespace:: System.Reflection.Emit

Assembly:: System.Reflection.Emit.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Package:: System.Reflection.Emit v4.7.0

Source:: FieldBuilder.cs

Source:: FieldBuilder.cs

Source:: FieldBuilder.cs

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.

Specifies the field layout.

public:
 void SetOffset(int iOffset);

public void SetOffset (int iOffset);

member this.SetOffset : int -> unit

Public Sub SetOffset (iOffset As Integer)

Parameters

iOffset: Int32

The offset of the field within the type containing this field.

Exceptions

InvalidOperationException

The containing type has been created using CreateType().

ArgumentException

iOffset is less than zero.

Remarks

The following code sample illustrates the use of SetOffset.

using namespace System;
using namespace System::Runtime::InteropServices;
using namespace System::Threading;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
using namespace System::Runtime::CompilerServices;
Type^ CreateType( AppDomain^ currentDomain )
{
   // Create an assembly.
   AssemblyName^ myAssemblyName = gcnew AssemblyName;
   myAssemblyName->Name = "DynamicAssembly";
   AssemblyBuilder^ myAssembly = currentDomain->DefineDynamicAssembly( myAssemblyName, AssemblyBuilderAccess::RunAndSave );

   // Create a dynamic module in Dynamic Assembly.
   ModuleBuilder^ myModuleBuilder = myAssembly->DefineDynamicModule( "MyModule", "MyModule.mod" );

   // Define a public class named S"MyClass" in the assembly.
   TypeBuilder^ myTypeBuilder = myModuleBuilder->DefineType( "MyClass", TypeAttributes::Public );
   TypeBuilder^ myTypeBuilder2 = myModuleBuilder->DefineType( "MyClass2", static_cast<TypeAttributes>(TypeAttributes::Public | TypeAttributes::BeforeFieldInit | TypeAttributes::SequentialLayout | TypeAttributes::AnsiClass | TypeAttributes::Sealed) );
   FieldBuilder^ myFieldBuilder1 = myTypeBuilder2->DefineField( "myBytes1", Byte::typeid, FieldAttributes::Public );
   FieldBuilder^ myFieldBuilder2 = myTypeBuilder2->DefineField( "myBytes2", Byte::typeid, FieldAttributes::Public );
   FieldBuilder^ myFieldBuilder3 = myTypeBuilder2->DefineField( "myErrorCode", short::typeid, FieldAttributes::Public );
   FieldBuilder^ myFieldBuilder4 = myTypeBuilder2->DefineField( "myReserved1", short::typeid, FieldAttributes::Public );
   FieldBuilder^ myFieldBuilder5 = myTypeBuilder2->DefineField( "myReserved2", short::typeid, FieldAttributes::Public );
   FieldBuilder^ myFieldBuilder6 = myTypeBuilder2->DefineField( "myPathName", array<char>::typeid,FieldAttributes::Public );
   myFieldBuilder6->SetMarshal( UnmanagedMarshal::DefineByValArray( 128 ) );
   myFieldBuilder6->SetOffset( 4 );
   Type^ myType1 = myTypeBuilder2->CreateType();

   // Create the PInvoke method for 'OpenFile' method of 'Kernel32.dll'.
   array<Type^>^myParameters = {String::typeid,myType1,UInt32::typeid};
   MethodBuilder^ myMethodBuilder = myTypeBuilder->DefinePInvokeMethod( "OpenFile", "kernel32.dll", static_cast<MethodAttributes>(MethodAttributes::Public | MethodAttributes::Static | MethodAttributes::HideBySig), CallingConventions::Standard, IntPtr::typeid, myParameters, CallingConvention::Winapi, CharSet::None );
   Type^ myAttributeType = MethodImplAttribute::typeid;
   array<Type^>^type1 = {MethodImplOptions::typeid};
   ConstructorInfo^ myConstructorInfo = myAttributeType->GetConstructor( type1 );
   array<Object^>^obj1 = {MethodImplOptions::PreserveSig};
   CustomAttributeBuilder^ myAttributeBuilder = gcnew CustomAttributeBuilder( myConstructorInfo,obj1 );
   myMethodBuilder->SetCustomAttribute( myAttributeBuilder );
   ParameterBuilder^ myParameterBuilder2 = myMethodBuilder->DefineParameter( 2, ParameterAttributes::Out, "myClass2" );
   Type^ myType = myTypeBuilder->CreateType();
   myAssembly->Save( "EmittedAssembly.dll" );
   return myType;
}

int main()
{
   try
   {
      Type^ myType = CreateType( Thread::GetDomain() );
      Type^ myClass2 = myType->Module->GetType( "MyClass2" );
      Object^ myParam2 = Activator::CreateInstance( myClass2 );
      UInt32 myUint = 0x00000800;
      array<Object^>^myArgs = {"MyFile.Txt",myParam2,myUint};
      Object^ myObject = myType->InvokeMember( "OpenFile", static_cast<BindingFlags>(BindingFlags::Public | BindingFlags::InvokeMethod | BindingFlags::Static), nullptr, nullptr, myArgs );
      Console::WriteLine( "MyClass::OpenFile method returned: \"{0}\"", myObject );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception Caught {0}", e->Message );
   }
}

using System;
using System.Runtime.InteropServices;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;
using System.Security.Permissions;
using System.Runtime.CompilerServices;

public class FieldBuilder_Sample
{
   public static Type CreateType(AppDomain currentDomain)
   {
      // Create an assembly.
      AssemblyName myAssemblyName = new AssemblyName();
      myAssemblyName.Name = "DynamicAssembly";
      AssemblyBuilder myAssembly =
         currentDomain.DefineDynamicAssembly(myAssemblyName,AssemblyBuilderAccess.RunAndSave);
      // Create a dynamic module in Dynamic Assembly.
      ModuleBuilder myModuleBuilder=myAssembly.DefineDynamicModule("MyModule","MyModule.mod");
      // Define a public class named "MyClass" in the assembly.
      TypeBuilder myTypeBuilder= myModuleBuilder.DefineType("MyClass",TypeAttributes.Public);
      TypeBuilder myTypeBuilder2 = myModuleBuilder.DefineType("MyClass2",
         TypeAttributes.Public|TypeAttributes.BeforeFieldInit|TypeAttributes.SequentialLayout|TypeAttributes.AnsiClass|TypeAttributes.Sealed);
      FieldBuilder myFieldBuilder1= myTypeBuilder2.DefineField("myBytes1",
                                    typeof(byte),FieldAttributes.Public);
      FieldBuilder myFieldBuilder2= myTypeBuilder2.DefineField("myBytes2",
                                    typeof(byte),FieldAttributes.Public);
      FieldBuilder myFieldBuilder3= myTypeBuilder2.DefineField("myErrorCode",
                                    typeof(short),FieldAttributes.Public);
      FieldBuilder myFieldBuilder4= myTypeBuilder2.DefineField("myReserved1",
                                    typeof(short),FieldAttributes.Public);
      FieldBuilder myFieldBuilder5= myTypeBuilder2.DefineField("myReserved2",
                                    typeof(short),FieldAttributes.Public);
      FieldBuilder myFieldBuilder6= myTypeBuilder2.DefineField("myPathName",
                                    typeof(char[]),FieldAttributes.Public);
      myFieldBuilder6.SetMarshal(UnmanagedMarshal.DefineByValArray(128));
      myFieldBuilder6.SetOffset(4);
      Type myType1 = myTypeBuilder2.CreateType();
      // Create the PInvoke method for 'OpenFile' method of 'Kernel32.dll'.
      Type[] myParameters={ typeof(string), myType1 ,typeof(uint)};
      MethodBuilder myMethodBuilder= myTypeBuilder.DefinePInvokeMethod("OpenFile",
                                     "kernel32.dll",MethodAttributes.Public|MethodAttributes.Static|MethodAttributes.HideBySig,
                                       CallingConventions.Standard,typeof(IntPtr),
                                       myParameters,CallingConvention.Winapi,CharSet.None);
      Type myAttributeType = typeof(MethodImplAttribute);
      ConstructorInfo myConstructorInfo =
         myAttributeType.GetConstructor(new Type[1]{typeof(MethodImplOptions)});
      CustomAttributeBuilder myAttributeBuilder = new CustomAttributeBuilder(myConstructorInfo,
                                                   new object[1]{MethodImplOptions.PreserveSig});
      myMethodBuilder.SetCustomAttribute(myAttributeBuilder);
      ParameterBuilder myParameterBuilder2=myMethodBuilder.DefineParameter(2,
                                            ParameterAttributes.Out,"myClass2");
      Type myType=myTypeBuilder.CreateType();
      myAssembly.Save("EmittedAssembly.dll");
      return myType;
   }

   public static void Main()
   {
      try
      {
         Type myType = CreateType(Thread.GetDomain());
         Type myClass2 = myType.Module.GetType("MyClass2");
         object myParam2 = Activator.CreateInstance(myClass2);
         uint myUint=0x00000800;
         object[] myArgs= {"MyFile.Txt",myParam2,myUint};
         Object myObject  = myType.InvokeMember("OpenFile",BindingFlags.Public |
            BindingFlags.InvokeMethod | BindingFlags.Static,null,null,myArgs);
         Console.WriteLine("MyClass.OpenFile method returned: \"{0}\"", myObject);
      }
      catch(Exception e)
      {
         Console.WriteLine("Exception Caught "+e.Message);
      }
   }
}

Imports System.Runtime.InteropServices
Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Security.Permissions
Imports System.Runtime.CompilerServices

Public Class FieldBuilder_Sample

   Public Shared Function CreateType(ByVal currentDomain As AppDomain) As Type

      ' Create an assembly.
      Dim myAssemblyName As New AssemblyName()
      myAssemblyName.Name = "DynamicAssembly"
      Dim myAssembly As AssemblyBuilder = currentDomain.DefineDynamicAssembly(myAssemblyName, _
                                          AssemblyBuilderAccess.RunAndSave)
      ' Create a dynamic module in Dynamic Assembly.
      Dim myModuleBuilder As ModuleBuilder = myAssembly.DefineDynamicModule("MyModule", _
                                            "MyModule.mod")
      ' Define a public class named "MyClass" in the assembly.
      Dim myTypeBuilder As TypeBuilder = myModuleBuilder.DefineType("MyClass", _
                                         TypeAttributes.Public)
      Dim myTypeBuilder2 As TypeBuilder = myModuleBuilder.DefineType("MyClass2", _
         TypeAttributes.Public Or TypeAttributes.BeforeFieldInit Or _
         TypeAttributes.SequentialLayout Or TypeAttributes.AnsiClass Or TypeAttributes.Sealed)
      Dim myFieldBuilder1 As FieldBuilder = myTypeBuilder2.DefineField("myBytes1", _
         GetType(Byte), FieldAttributes.Public)
      Dim myFieldBuilder2 As FieldBuilder = myTypeBuilder2.DefineField("myBytes2", _
         GetType(Byte), FieldAttributes.Public)
      Dim myFieldBuilder3 As FieldBuilder = myTypeBuilder2.DefineField("myErrorCode", _
         GetType(Short), FieldAttributes.Public)
      Dim myFieldBuilder4 As FieldBuilder = myTypeBuilder2.DefineField("myReserved1", _
         GetType(Short), FieldAttributes.Public)
      Dim myFieldBuilder5 As FieldBuilder = myTypeBuilder2.DefineField("myReserved2", _
         GetType(Short), FieldAttributes.Public)
      Dim myFieldBuilder6 As FieldBuilder = myTypeBuilder2.DefineField("myPathName", _
         GetType(Char()), FieldAttributes.Public)
      myFieldBuilder6.SetMarshal(UnmanagedMarshal.DefineByValArray(128))
      myFieldBuilder6.SetOffset(4)
      Dim myType1 As Type = myTypeBuilder2.CreateType()
      ' Create the PInvoke method for 'OpenFile' method of 'Kernel32.dll'.
      Dim myParameters As Type() = {GetType(String), myType1, GetType(System.UInt32)}
      Dim myMethodBuilder As MethodBuilder = myTypeBuilder.DefinePInvokeMethod("OpenFile", _
         "kernel32.dll", MethodAttributes.Public Or MethodAttributes.Static Or _
         MethodAttributes.HideBySig, CallingConventions.Standard, GetType(IntPtr), _
         myParameters, CallingConvention.Winapi, CharSet.None)
      Dim myAttributeType As Type = GetType(MethodImplAttribute)
      Dim myConstructorInfo As ConstructorInfo = myAttributeType.GetConstructor(New Type(0) _
         {GetType(MethodImplOptions)})
      Dim myAttributeBuilder As New CustomAttributeBuilder(myConstructorInfo, _
         New Object() {MethodImplOptions.PreserveSig})
      myMethodBuilder.SetCustomAttribute(myAttributeBuilder)
      Dim myParameterBuilder2 As ParameterBuilder = myMethodBuilder.DefineParameter(2, _
         ParameterAttributes.Out, "myClass2")
      Dim myType As Type = myTypeBuilder.CreateType()
      myAssembly.Save("EmittedAssembly.dll")
      Return myType
   End Function 'CreateType

   <PermissionSetAttribute(SecurityAction.Demand, Name:="FullTrust")> _
   Public Shared Sub Main()
      Try
         Dim myType As Type = CreateType(Thread.GetDomain())
         Dim myClass2 As Type = myType.Module.GetType("MyClass2")
         Dim myParam2 As Object = Activator.CreateInstance(myClass2)
         Dim myUint As System.UInt32
         myUint.Parse("800")

         Dim myArgs As Object() = {"MyFile.Txt", myParam2, myUint}
         Dim myObject As Object = myType.InvokeMember("OpenFile", _
                                    BindingFlags.Public Or BindingFlags.InvokeMethod Or _
                                    BindingFlags.Static, Nothing, Nothing, myArgs)
         Console.WriteLine("MyClass.OpenFile method returned: '{0}'", myObject)
      Catch e As Exception
         Console.WriteLine("Exception Caught: " & e.Message)
      End Try
   End Sub
End Class

Applies to

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