FieldInfo.IsInitOnly Özellik

Tanım

Ad Alanı:

System.Reflection

Bütünleştirilmiş Kod:

System.Runtime.dll

Kaynak:

FieldInfo.cs

Alanın yalnızca oluşturucunun gövdesinde ayarlanıp ayarlanamayacağını belirten bir değer alır.

public:
 property bool IsInitOnly { bool get(); };

public bool IsInitOnly { get; }

member this.IsInitOnly : bool

Public ReadOnly Property IsInitOnly As Boolean

Özellik Değeri

Boolean

true alanında InitOnly özniteliği ayarlanmışsa; aksi takdirde , false.

Örnekler

Aşağıdaki örnekte iki alan oluşturulur. İkinci alan salt okunurdur, erişimci ayarlı değildir ve IsInitOnly olarak trueayarlanmıştır.

using namespace System;
using namespace System::Reflection;

//Make two fields, one public and one read-only.
public ref class Myfielda
{
public:
   String^ field;
   Myfielda()
      : field( "A - public field" )
   {}


   property String^ Field 
   {
      String^ get()
      {
         return field;
      }

      void set( String^ value )
      {
         if ( field != value )
         {
            field = value;
         }
      }

   }

};

public ref class Myfieldb
{
private:
   String^ const field;

public:
   Myfieldb()
      : field( "B - readonly field" )
   {}


   property String^ Field 
   {
      String^ get()
      {
         return field;
      }

   }

};

int main()
{
   Console::WriteLine( "\nReflection.FieldInfo" );
   Myfielda^ myfielda = gcnew Myfielda;
   Myfieldb^ myfieldb = gcnew Myfieldb;
   
   //Get the Type and FieldInfo.
   Type^ MyTypea = Type::GetType( "Myfielda" );
   FieldInfo^ Myfieldinfoa = MyTypea->GetField( "field", static_cast<BindingFlags>(BindingFlags::Public | BindingFlags::Instance) );
   Type^ MyTypeb = Type::GetType( "Myfieldb" );
   FieldInfo^ Myfieldinfob = MyTypeb->GetField( "field", static_cast<BindingFlags>(BindingFlags::NonPublic | BindingFlags::Instance) );
   
   //Modify the fields.
   //Note that Myfieldb is not modified, as it is
   //read-only (IsInitOnly is True).
   myfielda->field = "A- modified";
   
   //Myfieldb.field = "B- modified";
   //For the first field, get and display the name, field, and IsInitOnly state.
   Console::Write( "\n{0} - {1}, IsInitOnly = {2} ", MyTypea->FullName, Myfieldinfoa->GetValue( myfielda ), Myfieldinfoa->IsInitOnly );
   
   //For the second field get and display the name, field, and IsInitOnly state.
   Console::Write( "\n{0} - {1}, IsInitOnly = {2} ", MyTypeb->FullName, Myfieldinfob->GetValue( myfieldb ), Myfieldinfob->IsInitOnly );
   return 0;
}

using System;
using System.Reflection;

//Make two fields, one public and one read-only.
public class Myfielda
{
    public string field = "A - public modifiable field";
}
public class Myfieldb
{
    public readonly string field = "B - readonly field";
}

public class Myfieldinfo
{
    public static int Main()
    {
        Console.WriteLine("\nReflection.FieldInfo");
        Myfielda Myfielda = new Myfielda();
        Myfieldb Myfieldb = new Myfieldb();

        //Get the Type and FieldInfo.
        Type MyTypea = typeof(Myfielda);
        FieldInfo Myfieldinfoa = MyTypea.GetField("field",
            BindingFlags.Public | BindingFlags.Instance);
        Type MyTypeb = typeof(Myfieldb);
        FieldInfo Myfieldinfob = MyTypeb.GetField("field",
            BindingFlags.Public | BindingFlags.Instance);

        //Modify the fields.
        //Note that Myfieldb is not modified, as it is
        //read-only (IsInitOnly is True).
        Myfielda.field = "A - modified";
        //Myfieldb.field = "B - modified";

        //For the first field, get and display the name, field, and IsInitOnly state.
        Console.Write("\n{0} - {1}, IsInitOnly = {2} ",
            MyTypea.FullName,
            Myfieldinfoa.GetValue(Myfielda),
            Myfieldinfoa.IsInitOnly);

        //For the second field get and display the name, field, and IsInitOnly state.
        Console.Write("\n{0} - {1}, IsInitOnly = {2} ",
            MyTypeb.FullName,
            Myfieldinfob.GetValue(Myfieldb),
            Myfieldinfob.IsInitOnly);

        return 0;
    }
}

Imports System.Reflection

'Make two fields, one public and one read-only.
Public Class Myfielda
    Public field As String = "A - public modifiable field"
End Class

Public Class Myfieldb
    Public ReadOnly field As String = "B - readonly field"
End Class

Public Class Myfieldinfo
    Public Shared Function Main() As Integer
        Console.WriteLine("Reflection.FieldInfo")
        Console.WriteLine()
        Dim Myfielda As New Myfielda()
        Dim Myfieldb As New Myfieldb()

        'Get the Type and FieldInfo.
        Dim MyTypea As Type = GetType(Myfielda)
        Dim Myfieldinfoa As FieldInfo = MyTypea.GetField("field", _
            BindingFlags.Public Or BindingFlags.Instance)
        Dim MyTypeb As Type = GetType(Myfieldb)
        Dim Myfieldinfob As FieldInfo = MyTypeb.GetField("field", _
            BindingFlags.Public Or BindingFlags.Instance)

        'Modify the fields.
        'Note that Myfieldb is not modified, as it is
        'read-only (IsInitOnly is True).
        Myfielda.field = "A - modified"
        'For the first field, get and display the name, field, and IsInitOnly state.
        Console.WriteLine("{0} - {1}, IsInitOnly = {2} ", MyTypea.FullName, _
            Myfieldinfoa.GetValue(Myfielda), Myfieldinfoa.IsInitOnly)
        'For the second field get and display the name, field, and IsInitOnly state.
        Console.WriteLine("{0} - {1}, IsInitOnly = {2} ", MyTypeb.FullName, _
            Myfieldinfob.GetValue(Myfieldb), Myfieldinfob.IsInitOnly)

        Return 0
    End Function 'Main
End Class

Bu kod şu çıkışı oluşturur:

Reflection.FieldInfo

Myfielda - A- modified, IsInitOnly = False

Myfieldb - B readonly field, IsInitOnly = True

Açıklamalar

Döndürülen değer ise true, alan yalnızca başlatılabilir ve bundan sonra salt okunur olur.

özelliğini almak IsInitOnly için önce sınıfını Typealın. içinden Typeöğesini alın FieldInfo. FieldInfo'den özelliğini alınIsInitOnly. Ortak olmayan bir alana erişmek için, BindingFlags.NonPublic yönteminde veya BindingFlags.Instance her ikisiyle BindingFlags.Static birleştirinGetField.

IsInitOnly özniteliği ayarlandığında FieldAttributes.InitOnly özelliği ayarlanır.

Ayrıca bkz.

• FieldAttributes
• GetField(String, BindingFlags)
• Type