LocalBuilder Class

Definition

Namespace:

System.Reflection.Emit

Assembly:

System.Reflection.Emit.ILGeneration.dll

Source:

LocalBuilder.cs

Represents a local variable within a method or constructor.

public ref class LocalBuilder abstract : System::Reflection::LocalVariableInfo

public abstract class LocalBuilder : System.Reflection.LocalVariableInfo

type LocalBuilder = class
    inherit LocalVariableInfo

Public MustInherit Class LocalBuilder
Inherits LocalVariableInfo

Inheritance

Object

LocalVariableInfo

LocalBuilder

Examples

The following example creates a static method (Shared in Visual Basic) named Function1 that returns a string and has a parameter of type Int32. In the body of the method, the code example creates LocalBuilder objects representing two local variables, and sets symbol information for the local variables. The method does not do anything significant, but the method body demonstrates storing a parameter to a local variable, storing a literal string to a local variable, and loading a local variable.

using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;
using namespace System::Threading;
int main()
{
    // Create an assembly.
    AssemblyName^ myAssemblyName = gcnew AssemblyName;
    myAssemblyName->Name = "SampleAssembly";
    AssemblyBuilder^ myAssembly = Thread::GetDomain()->DefineDynamicAssembly( 
        myAssemblyName, AssemblyBuilderAccess::RunAndSave );

    // Create a module. For a single-file assembly the module
    // name is usually the same as the assembly name.
    ModuleBuilder^ myModule = myAssembly->DefineDynamicModule( 
        myAssemblyName->Name, myAssemblyName->Name + ".dll", true );

    // Define a public class 'Example'.
    TypeBuilder^ myTypeBuilder = myModule->DefineType( "Example", TypeAttributes::Public );

    // Create the 'Function1' public method, which takes an integer
    // and returns a string.
    MethodBuilder^ myMethod = myTypeBuilder->DefineMethod( "Function1", 
        MethodAttributes::Public | MethodAttributes::Static, String::typeid, 
        gcnew array<Type^> { int::typeid } );

    // Generate IL for 'Function1'. The function body demonstrates
    // assigning an argument to a local variable, assigning a 
    // constant string to a local variable, and putting the contents
    // of local variables on the stack.
    ILGenerator^ myMethodIL = myMethod->GetILGenerator();

    // Create local variables named myString and myInt.
    LocalBuilder^ myLB1 = myMethodIL->DeclareLocal( String::typeid );
    myLB1->SetLocalSymInfo( "myString" );
    Console::WriteLine( "local 'myString' type is: {0}", myLB1->LocalType );

    LocalBuilder^ myLB2 = myMethodIL->DeclareLocal( int::typeid );
    myLB2->SetLocalSymInfo( "myInt", 1, 2 );
    Console::WriteLine( "local 'myInt' type is: {0}", myLB2->LocalType );

    // Store the function argument in myInt.
    myMethodIL->Emit( OpCodes::Ldarg_0 );
    myMethodIL->Emit( OpCodes::Stloc_1 );

    // Store a literal value in myString, and return the value.
    myMethodIL->Emit( OpCodes::Ldstr, "string value"  );
    myMethodIL->Emit( OpCodes::Stloc_0 );
    myMethodIL->Emit( OpCodes::Ldloc_0 );
    myMethodIL->Emit( OpCodes::Ret );

    // Create "Example" class.
    Type^ myType1 = myTypeBuilder->CreateType();
    Console::WriteLine( "'Example' is created." );

    myAssembly->Save(myAssemblyName->Name + ".dll");
    Console::WriteLine( "'{0}' is created.", myAssemblyName->Name + ".dll" );

    // Invoke 'Function1' method of 'Example', passing the value 42.
    Object^ myObject2 = myType1->InvokeMember( "Function1", 
        BindingFlags::InvokeMethod, nullptr, nullptr, 
        gcnew array<Object^> { 42 } );

    Console::WriteLine( "Example::Function1 returned: {0}", myObject2 );
}
/* This code example produces the following output:

local 'myString' type is: System.String
local 'myInt' type is: System.Int32
'Example' is created.
'SampleAssembly.dll' is created.
Example::Function1 returned: string value
 */

using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Threading;

class LocalBuilder_Sample
{
    public static void Main()
    {
        // Create an assembly.
        AssemblyName myAssemblyName = new AssemblyName();
        myAssemblyName.Name = "SampleAssembly";

        AssemblyBuilder myAssembly =
           Thread.GetDomain().DefineDynamicAssembly(myAssemblyName,
               AssemblyBuilderAccess.RunAndSave);

        // Create a module. For a single-file assembly the module
        // name is usually the same as the assembly name.
        ModuleBuilder myModule =
            myAssembly.DefineDynamicModule(myAssemblyName.Name,
                myAssemblyName.Name + ".dll", true);

        // Define a public class 'Example'.
        TypeBuilder myTypeBuilder =
            myModule.DefineType("Example", TypeAttributes.Public);

        // Create the 'Function1' public method, which takes an integer
        // and returns a string.
        MethodBuilder myMethod = myTypeBuilder.DefineMethod("Function1",
           MethodAttributes.Public | MethodAttributes.Static,
           typeof(String), new Type[] { typeof(int) });

        // Generate IL for 'Function1'. The function body demonstrates
        // assigning an argument to a local variable, assigning a
        // constant string to a local variable, and putting the contents
        // of local variables on the stack.
        ILGenerator myMethodIL = myMethod.GetILGenerator();

        // Create local variables named myString and myInt.
        LocalBuilder myLB1 = myMethodIL.DeclareLocal(typeof(string));
        myLB1.SetLocalSymInfo("myString");
        Console.WriteLine("local 'myString' type is: {0}", myLB1.LocalType);

        LocalBuilder myLB2 = myMethodIL.DeclareLocal(typeof(int));
        myLB2.SetLocalSymInfo("myInt", 1, 2);
        Console.WriteLine("local 'myInt' type is: {0}", myLB2.LocalType);

        // Store the function argument in myInt.
        myMethodIL.Emit(OpCodes.Ldarg_0 );
        myMethodIL.Emit(OpCodes.Stloc_1 );

        // Store a literal value in myString, and return the value.
        myMethodIL.Emit(OpCodes.Ldstr, "string value"  );
        myMethodIL.Emit(OpCodes.Stloc_0 );
        myMethodIL.Emit(OpCodes.Ldloc_0 );
        myMethodIL.Emit(OpCodes.Ret );

        // Create "Example" class.
        Type myType1 = myTypeBuilder.CreateType();
        Console.WriteLine("'Example' is created.");

        myAssembly.Save(myAssemblyName.Name + ".dll");
        Console.WriteLine( "'{0}' is created.", myAssemblyName.Name + ".dll" );

        // Invoke 'Function1' method of 'Example', passing the value 42.
        Object myObject2 = myType1.InvokeMember("Function1",
            BindingFlags.InvokeMethod, null, null, new Object[] { 42 });

        Console.WriteLine("Example.Function1 returned: {0}", myObject2);
    }
}
/* This code example produces the following output:

local 'myString' type is: System.String
local 'myInt' type is: System.Int32
'Example' is created.
'SampleAssembly.dll' is created.
Example.Function1 returned: string value
 */

Imports System.Reflection
Imports System.Reflection.Emit
Imports System.Threading

Class LocalBuilder_Sample

    Public Shared Sub Main()

        ' Create an assembly.
        Dim myAssemblyName As New AssemblyName()
        myAssemblyName.Name = "SampleAssembly"

        Dim myAssembly As AssemblyBuilder = _
            Thread.GetDomain().DefineDynamicAssembly( myAssemblyName, _
                             AssemblyBuilderAccess.RunAndSave )

        ' Create a module. For a single-file assembly the module
        ' name is usually the same as the assembly name.
        Dim myModule As ModuleBuilder = _
            myAssembly.DefineDynamicModule(myAssemblyName.Name, _
                myAssemblyName.Name & ".dll", True)

        ' Define a public class 'Example'.
        Dim myTypeBuilder As TypeBuilder = _
            myModule.DefineType("Example", TypeAttributes.Public)

        ' Create the 'Function1' public method, which takes an Integer
        ' and returns a string.
        Dim myMethod As MethodBuilder = myTypeBuilder.DefineMethod("Function1", _
            MethodAttributes.Public Or MethodAttributes.Static, _
            GetType(String), New Type() { GetType(Integer) })

        ' Generate IL for 'Function1'. The function body demonstrates
        ' assigning an argument to a local variable, assigning a 
        ' constant string to a local variable, and putting the contents
        ' of local variables on the stack.
        Dim myMethodIL As ILGenerator = myMethod.GetILGenerator()

        ' Create local variables named myString and myInt.
        Dim myLB1 As LocalBuilder = myMethodIL.DeclareLocal(GetType(String))
        myLB1.SetLocalSymInfo("myString")
        Console.WriteLine("local 'myString' type is: {0}", myLB1.LocalType)

        Dim myLB2 As LocalBuilder = myMethodIL.DeclareLocal(GetType(Integer))
        myLB2.SetLocalSymInfo("myInt", 1, 2)
        Console.WriteLine("local 'myInt' type is: {0}", myLB2.LocalType)

        ' Store the function argument in myInt.
        myMethodIL.Emit(OpCodes.Ldarg_0 )
        myMethodIL.Emit(OpCodes.Stloc_1 )

        ' Store a literal value in myString, and return the value.
        myMethodIL.Emit(OpCodes.Ldstr, "string value"  )
        myMethodIL.Emit(OpCodes.Stloc_0 )
        myMethodIL.Emit(OpCodes.Ldloc_0 )
        myMethodIL.Emit(OpCodes.Ret )

        ' Create "Example" class.
        Dim myType1 As Type = myTypeBuilder.CreateType()
        Console.WriteLine("'Example' is created.")

        myAssembly.Save(myAssemblyName.Name & ".dll")
        Console.WriteLine( "'{0}' is created.", myAssemblyName.Name & ".dll" )

        ' Invoke 'Function1' method of 'Example', passing the value 42.
        Dim myObject2 As Object = myType1.InvokeMember("Function1", _
            BindingFlags.InvokeMethod, Nothing, Nothing, New Object() { 42 })

        Console.WriteLine("Example.Function1 returned: {0}", myObject2)

   End Sub 
End Class 

' This code example produces the following output:
'
'local 'myString' type is: System.String
'local 'myInt' type is: System.Int32
''Example' is created.
''SampleAssembly.dll' is created.
'Example.Function1 returned: string value

Remarks

A LocalBuilder object can be defined using the DeclareLocal method.

Constructors

LocalBuilder()

Initializes a new instance of the LocalBuilder class.

Properties

IsPinned	Gets a value indicating whether the object referred to by the local variable is pinned in memory.
LocalIndex	Gets the zero-based index of the local variable within the method body.
LocalType	Gets the type of the local variable.

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
SetLocalSymInfo(String)	Sets the name of this local variable.
SetLocalSymInfoCore(String)	When overridden in a derived class, sets the name of this local variable.
ToString()	Returns a user-readable string that describes the local variable. (Inherited from LocalVariableInfo)