FieldAttributes FieldAttributes FieldAttributes FieldAttributes Enum

Definition

Specifies flags that describe the attributes of a field.

This enumeration has a FlagsAttribute attribute that allows a bitwise combination of its member values.

public enum class FieldAttributes
[System.Flags]
[System.Runtime.InteropServices.ComVisible(true)]
[Serializable]
public enum FieldAttributes
type FieldAttributes = 
Public Enum FieldAttributes
Inheritance
FieldAttributesFieldAttributesFieldAttributesFieldAttributes
Attributes
FlagsAttribute ComVisibleAttribute SerializableAttribute

Fields

Assembly Assembly Assembly Assembly 3

Specifies that the field is accessible throughout the assembly.

FamANDAssem FamANDAssem FamANDAssem FamANDAssem 2

Specifies that the field is accessible only by subtypes in this assembly.

Family Family Family Family 4

Specifies that the field is accessible only by type and subtypes.

FamORAssem FamORAssem FamORAssem FamORAssem 5

Specifies that the field is accessible by subtypes anywhere, as well as throughout this assembly.

FieldAccessMask FieldAccessMask FieldAccessMask FieldAccessMask 7

Specifies the access level of a given field.

HasDefault HasDefault HasDefault HasDefault 32768

Specifies that the field has a default value.

HasFieldMarshal HasFieldMarshal HasFieldMarshal HasFieldMarshal 4096

Specifies that the field has marshaling information.

HasFieldRVA HasFieldRVA HasFieldRVA HasFieldRVA 256

Specifies that the field has a relative virtual address (RVA). The RVA is the location of the method body in the current image, as an address relative to the start of the image file in which it is located.

InitOnly InitOnly InitOnly InitOnly 32

Specifies that the field is initialized only, and can be set only in the body of a constructor.

Literal Literal Literal Literal 64

Specifies that the field's value is a compile-time (static or early bound) constant. Any attempt to set it throws a FieldAccessException.

NotSerialized NotSerialized NotSerialized NotSerialized 128

Specifies that the field does not have to be serialized when the type is remoted.

PinvokeImpl PinvokeImpl PinvokeImpl PinvokeImpl 8192

Reserved for future use.

Private Private Private Private 1

Specifies that the field is accessible only by the parent type.

PrivateScope PrivateScope PrivateScope PrivateScope 0

Specifies that the field cannot be referenced.

Public Public Public Public 6

Specifies that the field is accessible by any member for whom this scope is visible.

ReservedMask ReservedMask ReservedMask ReservedMask 38144

Reserved.

RTSpecialName RTSpecialName RTSpecialName RTSpecialName 1024

Specifies that the common language runtime (metadata internal APIs) should check the name encoding.

SpecialName SpecialName SpecialName SpecialName 512

Specifies a special method, with the name describing how the method is special.

Static Static Static Static 16

Specifies that the field represents the defined type, or else it is per-instance.

Examples

In this example, three fields are built and the FieldAttributes values are displayed. A FieldAttributes value can contain more than one attribute, for example, both Public and Literal, as shown in the third field.

using namespace System;
using namespace System::Reflection;
using namespace System::Security::Permissions;

public ref class Demo
{
private:
    // Make three fields:
    // The first field is private.
    String^ m_field;

    // The second field is public.
public:
    String^ Field;

    // The third field is public and literal. 
    literal String^ FieldC = "String C";

    Demo() { m_field = "String A"; Field = "String B"; }
};

static void DisplayField(Object^ obj, FieldInfo^ f)
{ 
    // Display the field name, value, and attributes.
    //
    Console::WriteLine("{0} = \"{1}\"; attributes: {2}", 
        f->Name, f->GetValue(obj), f->Attributes);
};

void main()
{
    Console::WriteLine ("\nReflection.FieldAttributes");
    Demo^ d = gcnew Demo();

    // Get a Type object for Demo, and a FieldInfo for each of
    // the three fields. Use the FieldInfo to display field
    // name, value for the Demo object in d, and attributes.
    //
    Type^ myType = Demo::typeid;

    FieldInfo^ fiPrivate = myType->GetField("m_field",
        BindingFlags::NonPublic | BindingFlags::Instance);
    DisplayField(d, fiPrivate);

    FieldInfo^ fiPublic = myType->GetField("Field",
        BindingFlags::Public | BindingFlags::Instance);
    DisplayField(d, fiPublic);

    FieldInfo^ fiConstant = myType->GetField("FieldC",
        BindingFlags::Public | BindingFlags::Static);
    DisplayField(d, fiConstant);
}

/* This code example produces the following output:

Reflection.FieldAttributes
m_field = "String A"; attributes: Private
Field = "String B"; attributes: Public
FieldC = "String C"; attributes: Public, Static, Literal, HasDefault
 */
using System;
using System.Reflection;

public class Demo
{
    // Make three fields:
    // The first field is private.
    private string m_field = "String A";

    // The second field is public.
    public string Field = "String B";

    // The third field is public const (hence also literal and static),
    // with a default value.
    public const string FieldC = "String C";
}

public class Myfieldattributes
{
    public static void Main()
    {
        Console.WriteLine ("\nReflection.FieldAttributes");
        Demo d = new Demo();
 
        // Get a Type object for Demo, and a FieldInfo for each of
        // the three fields. Use the FieldInfo to display field
        // name, value for the Demo object in d, and attributes.
        //
        Type myType = typeof(Demo);
        FieldInfo fiPrivate = myType.GetField("m_field",
            BindingFlags.NonPublic | BindingFlags.Instance);
        DisplayField(d, fiPrivate);

        FieldInfo fiPublic = myType.GetField("Field",
            BindingFlags.Public | BindingFlags.Instance);
        DisplayField(d, fiPublic);

        FieldInfo fiConstant = myType.GetField("FieldC",
            BindingFlags.Public | BindingFlags.Static);
        DisplayField(d, fiConstant);
    }

    static void DisplayField(Object obj, FieldInfo f)
    { 
        // Display the field name, value, and attributes.
        //
        Console.WriteLine("{0} = \"{1}\"; attributes: {2}", 
            f.Name, f.GetValue(obj), f.Attributes);
    }
}

/* This code example produces the following output:

Reflection.FieldAttributes
m_field = "String A"; attributes: Private
Field = "String B"; attributes: Public
FieldC = "String C"; attributes: Public, Static, Literal, HasDefault
 */
Imports System
Imports System.Reflection
Imports Microsoft.VisualBasic

Public Class Demo
    ' Declare three fields.
    ' The first field is private.
    Private m_field As String = "String A"

    'The second field is public.
    Public Field As String = "String B"

    ' The third field is public and const, hence also static
    ' and literal with a default value.
    Public Const FieldC As String = "String C"

End Class

Module Module1
    Sub Main()
        ' Create an instance of the Demo class.
        Dim d As New Demo()

        Console.WriteLine(vbCrLf & "Reflection.FieldAttributes")

        ' Get a Type object for Demo, and a FieldInfo for each of
        ' the three fields. Use the FieldInfo to display field
        ' name, value for the Demo object in d, and attributes.
        '
        Dim myType As Type = GetType(Demo)

        Dim fiPrivate As FieldInfo = myType.GetField("m_field", _
            BindingFlags.NonPublic Or BindingFlags.Instance)
        DisplayField(d, fiPrivate)

        Dim fiPublic As FieldInfo = myType.GetField("Field", _
            BindingFlags.Public Or BindingFlags.Instance)
        DisplayField(d, fiPublic)

        Dim fiConstant As FieldInfo = myType.GetField("FieldC", _
            BindingFlags.Public Or BindingFlags.Static)
        DisplayField(d, fiConstant)
    End Sub

    Sub DisplayField(ByVal obj As Object, ByVal f As FieldInfo)

        ' Display the field name, value, and attributes.
        '
        Console.WriteLine("{0} = ""{1}""; attributes: {2}", _
            f.Name, f.GetValue(obj), f.Attributes)
    End Sub

End Module

' This code example produces the following output:
'
'm_field = "String A"; attributes: Private
'Field = "String B"; attributes: Public
'FieldC = "String C"; attributes: Public, Static, Literal, HasDefault

Remarks

FieldAttributes uses the value from FieldAccessMask to mask off only the parts of the attribute value that pertain to the accessibility. For example, the following code determines if Attributes has the public bit set.

FieldInfo^ fi = obj->GetType()->GetField("field1");

if ((fi->Attributes & FieldAttributes::FieldAccessMask) ==
    FieldAttributes::Public)
{
    Console::WriteLine("{0:s} is public. Value: {1:d}", fi->Name, fi->GetValue(obj));
}
FieldInfo fi = obj.GetType().GetField("field1");

if ((fi.Attributes & FieldAttributes.FieldAccessMask) ==
    FieldAttributes.Public)
{
    Console.WriteLine("{0:s} is public. Value: {1:d}", fi.Name, fi.GetValue(obj));
}
Dim fi As FieldInfo = obj.GetType().GetField("field1")

If (fi.Attributes And FieldAttributes.FieldAccessMask) = _
    FieldAttributes.Public Then
    Console.WriteLine("{0:s} is public. Value: {1:d}", fi.Name, fi.GetValue(obj))
End If

To get the FieldAttributes, first get the class Type. From the Type, get the FieldInfo. From the FieldInfo, get the Attributes.

The enumerated value is a number representing the bitwise OR of the attributes implemented on the field.

Applies to