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FieldInfo Class

Discovers the attributes of a field and provides access to field metadata.

Namespace: System.Reflection
Assembly: mscorlib (in mscorlib.dll)

'Declaration
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
<ClassInterfaceAttribute(ClassInterfaceType.None)> _
Public MustInherit Class FieldInfo
	Inherits MemberInfo
	Implements _FieldInfo
'Usage
Dim instance As FieldInfo

/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
/** @attribute ClassInterfaceAttribute(ClassInterfaceType.None) */ 
public abstract class FieldInfo extends MemberInfo implements _FieldInfo
SerializableAttribute 
ComVisibleAttribute(true) 
ClassInterfaceAttribute(ClassInterfaceType.None) 
public abstract class FieldInfo extends MemberInfo implements _FieldInfo

The field information is obtained from metadata. The FieldInfo class does not have a public constructor. FieldInfo objects are obtained by calling either the GetFields or GetField method of a Type object.

Fields are variables defined in the class. FieldInfo provides access to the metadata for a field within a class and provides dynamic set and get functionality for the field. The class is not loaded into memory until invoke or get is called on the object.

Notes to Inheritors When you inherit from FieldInfo, you must override the following members: GetValue and SetValue.

The following example uses the Type.GetFields method to get the field-related information from the FieldInfo class, and then displays field attributes.

Imports System
Imports System.Reflection
Imports Microsoft.VisualBasic

Public Class FieldInfoClass
    Public myField1 As Integer = 0
    Protected myField2 As String = Nothing

    Public Shared Sub Main()
        Dim myFieldInfo() As FieldInfo
        Dim myType As Type = GetType(FieldInfoClass)
        ' Get the type and fields of FieldInfoClass.
        myFieldInfo = myType.GetFields(BindingFlags.NonPublic Or _
                      BindingFlags.Instance Or BindingFlags.Public)
        Console.WriteLine(ControlChars.NewLine & "The fields of " & _
                      "FieldInfoClass class are " & ControlChars.NewLine)
        ' Display the field information of FieldInfoClass.
        Dim i As Integer
        For i = 0 To myFieldInfo.Length - 1
            Console.WriteLine(ControlChars.NewLine + "Name            : {0}", myFieldInfo(i).Name)
            Console.WriteLine("Declaring Type  : {0}", myFieldInfo(i).DeclaringType)
            Console.WriteLine("IsPublic        : {0}", myFieldInfo(i).IsPublic)
            Console.WriteLine("MemberType      : {0}", myFieldInfo(i).MemberType)
            Console.WriteLine("FieldType       : {0}", myFieldInfo(i).FieldType)
            Console.WriteLine("IsFamily        : {0}", myFieldInfo(i).IsFamily)
        Next i
    End Sub
End Class

import System.*;
import System.Reflection.*;

public class FieldInfoClass
{
    public int myField1 = 0;
    protected String myField2 = null;

    public static void main(String[] args)
    {
        FieldInfo myFieldInfo[];
        Type myType = FieldInfoClass.class.ToType();

        // Get the type and fields of FieldInfoClass.
        myFieldInfo = myType.GetFields(BindingFlags.NonPublic 
            | BindingFlags.Instance | BindingFlags.Public);
        Console.WriteLine("\nThe fields of " + "FieldInfoClass are \n");

        // Display the field information of FieldInfoClass.
        for (int i = 0; i < myFieldInfo.length; i++) {
            Console.WriteLine("\nName            : {0}",
                myFieldInfo[i].get_Name());
            Console.WriteLine("Declaring Type  : {0}", 
                myFieldInfo[i].get_DeclaringType());
            Console.WriteLine("IsPublic        : {0}", 
                System.Convert.ToString(myFieldInfo[i].get_IsPublic()));
            Console.WriteLine("MemberType      : {0}", 
                myFieldInfo[i].get_MemberType());
            Console.WriteLine("FieldType       : {0}",
                myFieldInfo[i].get_FieldType());
            Console.WriteLine("IsFamily        : {0}",
                System.Convert.ToString(myFieldInfo[i].get_IsFamily()));
        }
    } //main
} //FieldInfoClass

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0
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