FieldAttributes Enum
Definition
Important
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Specifies flags that describe the attributes of a field.
This enumeration supports a bitwise combination of its member values.
public enum class FieldAttributes
[System.Flags]
public enum FieldAttributes
[System.Flags]
[System.Serializable]
public enum FieldAttributes
[System.Flags]
[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public enum FieldAttributes
[<System.Flags>]
type FieldAttributes =
[<System.Flags>]
[<System.Serializable>]
type FieldAttributes =
[<System.Flags>]
[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type FieldAttributes =
Public Enum FieldAttributes
- Inheritance
- Attributes
Fields
Assembly | 3 | Specifies that the field is accessible throughout the assembly. |
FamANDAssem | 2 | Specifies that the field is accessible only by subtypes in this assembly. |
Family | 4 | Specifies that the field is accessible only by type and subtypes. |
FamORAssem | 5 | Specifies that the field is accessible by subtypes anywhere, as well as throughout this assembly. |
FieldAccessMask | 7 | Specifies the access level of a given field. |
HasDefault | 32768 | Specifies that the field has a default value. |
HasFieldMarshal | 4096 | Specifies that the field has marshaling information. |
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 | 32 | Specifies that the field is initialized only, and can be set only in the body of a constructor. |
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 | 128 | Specifies that the field does not have to be serialized when the type is remoted. |
PinvokeImpl | 8192 | Reserved for future use. |
Private | 1 | Specifies that the field is accessible only by the parent type. |
PrivateScope | 0 | Specifies that the field cannot be referenced. |
Public | 6 | Specifies that the field is accessible by any member for whom this scope is visible. |
ReservedMask | 38144 | Reserved. |
RTSpecialName | 1024 | Specifies that the common language runtime (metadata internal APIs) should check the name encoding. |
SpecialName | 512 | Specifies a special method, with the name describing how the method is special. |
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.Reflection
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.