EnumBuilder.DefineLiteral(String, Object) Metodo

Definizione

Spazio dei nomi:

System.Reflection.Emit

Assembly:

System.Reflection.Emit.dll

Origine:

EnumBuilder.cs

Definisce il campo statico denominato in un tipo di enumerazione con il valore costante specificato.

public:
 System::Reflection::Emit::FieldBuilder ^ DefineLiteral(System::String ^ literalName, System::Object ^ literalValue);

public System.Reflection.Emit.FieldBuilder DefineLiteral (string literalName, object? literalValue);

member this.DefineLiteral : string * obj -> System.Reflection.Emit.FieldBuilder

Public Function DefineLiteral (literalName As String, literalValue As Object) As FieldBuilder

Parametri

literalName

String

Nome del campo statico.

literalValue

Object

Valore costante del valore letterale.

Restituisce

FieldBuilder

Campo definito.

Esempio

Nell'esempio di codice seguente viene illustrata la costruzione di un'enumerazione all'interno di un assembly dinamico usando EnumBuilder. L'esempio definisce un'enumerazione denominata Elevation, con un tipo sottostante di Int32e crea due elementi: Low, con un valore pari a 0 e High, con un valore pari a 1. Dopo aver creato il tipo, l'assembly viene salvato con il nome TempAssembly.dll. È possibile usare il Ildasm.exe (IL Disassembler) per esaminare il contenuto di questo assembly.

Nota

Prima di .NET Framework versione 2.0, questo esempio di codice non produce un'enumerazione corretta.

using namespace System;
using namespace System::Reflection;
using namespace System::Reflection::Emit;

void main()
{
    // Get the current application domain for the current thread.
    AppDomain^ currentDomain = AppDomain::CurrentDomain;
      
    // Create a dynamic assembly in the current application domain, 
    // and allow it to be executed and saved to disk.
    AssemblyName^ aName = gcnew AssemblyName("TempAssembly");
    AssemblyBuilder^ ab = currentDomain->DefineDynamicAssembly( 
            aName, AssemblyBuilderAccess::RunAndSave);
      
    // Define a dynamic module in "TempAssembly" assembly. For a single-
    // module assembly, the module has the same name as the assembly.
    ModuleBuilder^ mb = 
            ab->DefineDynamicModule(aName->Name, aName->Name + ".dll");
      
    // Define a public enumeration with the name "Elevation" and an 
    // underlying type of Int32.
    EnumBuilder^ eb = 
            mb->DefineEnum("Elevation", TypeAttributes::Public, int::typeid);
      
    // Define two members, "High" and "Low".
    eb->DefineLiteral("Low", (Object^) 0);
    eb->DefineLiteral("High", 1);

    // Create the type and save the assembly.
    Type^ finished = eb->CreateType();
    ab->Save(aName->Name + ".dll");

    for each (Object^ o in Enum::GetValues(finished))
    {
        Console::WriteLine("{0}.{1} = {2}", finished, o, (int)o);
    }
}

/* This code example produces the following output:

Elevation.Low = 0
Elevation.High = 1
 */

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

class Example
{
    public static void Main()
    {
        // Get the current application domain for the current thread.
        AppDomain currentDomain = AppDomain.CurrentDomain;

        // Create a dynamic assembly in the current application domain,
        // and allow it to be executed and saved to disk.
        AssemblyName aName = new AssemblyName("TempAssembly");
        AssemblyBuilder ab = currentDomain.DefineDynamicAssembly(
            aName, AssemblyBuilderAccess.RunAndSave);

        // Define a dynamic module in "TempAssembly" assembly. For a single-
        // module assembly, the module has the same name as the assembly.
        ModuleBuilder mb = ab.DefineDynamicModule(aName.Name, aName.Name + ".dll");

        // Define a public enumeration with the name "Elevation" and an
        // underlying type of Integer.
        EnumBuilder eb = mb.DefineEnum("Elevation", TypeAttributes.Public, typeof(int));

        // Define two members, "High" and "Low".
        eb.DefineLiteral("Low", 0);
        eb.DefineLiteral("High", 1);

        // Create the type and save the assembly.
        Type finished = eb.CreateType();
        ab.Save(aName.Name + ".dll");

        foreach( object o in Enum.GetValues(finished) )
        {
            Console.WriteLine("{0}.{1} = {2}", finished, o, ((int) o));
        }
    }
}

/* This code example produces the following output:

Elevation.Low = 0
Elevation.High = 1
 */

Imports System.Reflection
Imports System.Reflection.Emit

Module Example
   
    Sub Main()
      
        ' Get the current application domain for the current thread.
        Dim currentDomain As AppDomain = AppDomain.CurrentDomain
      
        ' Create a dynamic assembly in the current application domain, 
        ' and allow it to be executed and saved to disk.
        Dim aName As AssemblyName = New AssemblyName("TempAssembly")
        Dim ab As AssemblyBuilder = currentDomain.DefineDynamicAssembly( _ 
            aName, AssemblyBuilderAccess.RunAndSave)
      
        ' Define a dynamic module in "TempAssembly" assembly. For a single-
        ' module assembly, the module has the same name as the assembly.
        Dim mb As ModuleBuilder = _
            ab.DefineDynamicModule(aName.Name, aName.Name & ".dll")
      
        ' Define a public enumeration with the name "Elevation" and an 
        ' underlying type of Integer.
        Dim eb As EnumBuilder = _
            mb.DefineEnum("Elevation", TypeAttributes.Public, GetType(Integer))
      
        ' Define two members, "High" and "Low".
        eb.DefineLiteral("Low", 0)
        eb.DefineLiteral("High", 1)

        ' Create the type and save the assembly.
        Dim finished As Type = eb.CreateType()
        ab.Save(aName.Name & ".dll")

        For Each o As Object In [Enum].GetValues(finished)
            Console.WriteLine("{0}.{1} = {2}", finished, o, CInt(o))
        Next
   End Sub
End Module

' This code example produces the following output:
'
'Elevation.Low = 0
'Elevation.High = 1

Commenti

Il campo definito avrà gli attributi Publicdel campo , Statice Literal imposta.

Nota

Nelle versioni di .NET Framework 1.0 e 1.1 è necessario definire le enumerazioni usando TypeBuilder perché EnumBuilder genera enumerazioni i cui elementi sono di tipo anziché il tipo Int32 di enumerazione. In .NET Framework versione 2.0 EnumBuilder , genera enumerazioni i cui elementi hanno il tipo corretto.