FieldInfo Class

Definition

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

[System.Runtime.InteropServices.ClassInterface(System.Runtime.InteropServices.ClassInterfaceType.None)]
[System.Runtime.InteropServices.ComVisible(true)]
public abstract class FieldInfo : System.Reflection.MemberInfo, System.Runtime.InteropServices._FieldInfo
Inheritance
FieldInfo
Derived
Attributes
Implements

Inherited Members

System.Object

System.Reflection.MemberInfo

Examples

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

using namespace System;
using namespace System::Reflection;
public ref class FieldInfoClass
{
public:
   int myField1;

protected:
   String^ myField2;
};

int main()
{
   array<FieldInfo^>^myFieldInfo;
   Type^ myType = FieldInfoClass::typeid;

   // Get the type and fields of FieldInfoClass.
   myFieldInfo = myType->GetFields( static_cast<BindingFlags>(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 ]->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 );
   }
}
using System;
using System.Reflection;

public class FieldInfoClass
{
    public int myField1 = 0;
    protected string myField2 = null;
    public static void Main()
    {
        FieldInfo[] myFieldInfo;
        Type myType = typeof(FieldInfoClass);
        // 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].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);
        }
    }
}
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

Remarks

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.

Constructors

FieldInfo()

Initializes a new instance of the FieldInfo class.

Properties

Attributes

Gets the attributes associated with this field.

FieldHandle

Gets a RuntimeFieldHandle, which is a handle to the internal metadata representation of a field.

FieldType

Gets the type of this field object.

IsAssembly

Gets a value indicating whether the potential visibility of this field is described by Assembly; that is, the field is visible at most to other types in the same assembly, and is not visible to derived types outside the assembly.

IsFamily

Gets a value indicating whether the visibility of this field is described by Family; that is, the field is visible only within its class and derived classes.

IsFamilyAndAssembly

Gets a value indicating whether the visibility of this field is described by FamANDAssem; that is, the field can be accessed from derived classes, but only if they are in the same assembly.

IsFamilyOrAssembly

Gets a value indicating whether the potential visibility of this field is described by FamORAssem; that is, the field can be accessed by derived classes wherever they are, and by classes in the same assembly.

IsInitOnly

Gets a value indicating whether the field can only be set in the body of the constructor.

IsLiteral

Gets a value indicating whether the value is written at compile time and cannot be changed.

IsNotSerialized

Gets a value indicating whether this field has the NotSerialized attribute.

IsPinvokeImpl

Gets a value indicating whether the corresponding PinvokeImpl attribute is set in FieldAttributes.

IsPrivate

Gets a value indicating whether the field is private.

IsPublic

Gets a value indicating whether the field is public.

IsSecurityCritical

Gets a value that indicates whether the current field is security-critical or security-safe-critical at the current trust level.

IsSecuritySafeCritical

Gets a value that indicates whether the current field is security-safe-critical at the current trust level.

IsSecurityTransparent

Gets a value that indicates whether the current field is transparent at the current trust level.

IsSpecialName

Gets a value indicating whether the corresponding SpecialName attribute is set in the FieldAttributes enumerator.

IsStatic

Gets a value indicating whether the field is static.

MemberType

Gets a MemberTypes value indicating that this member is a field.

Methods

Equals(Object)

Returns a value that indicates whether this instance is equal to a specified object.

GetFieldFromHandle(RuntimeFieldHandle)

Gets a FieldInfo for the field represented by the specified handle.

GetFieldFromHandle(RuntimeFieldHandle, RuntimeTypeHandle)

Gets a FieldInfo for the field represented by the specified handle, for the specified generic type.

GetHashCode()

Returns the hash code for this instance.

GetOptionalCustomModifiers()

Gets an array of types that identify the optional custom modifiers of the field.

GetRawConstantValue()

Returns a literal value associated with the field by a compiler.

GetRequiredCustomModifiers()

Gets an array of types that identify the required custom modifiers of the property.

GetValue(Object)

When overridden in a derived class, returns the value of a field supported by a given object.

GetValueDirect(TypedReference)

Returns the value of a field supported by a given object.

SetValue(Object, Object)

Sets the value of the field supported by the given object.

SetValue(Object, Object, BindingFlags, Binder, CultureInfo)

When overridden in a derived class, sets the value of the field supported by the given object.

SetValueDirect(TypedReference, Object)

Sets the value of the field supported by the given object.

Operators

Equality(FieldInfo, FieldInfo)

Indicates whether two FieldInfo objects are equal.

Inequality(FieldInfo, FieldInfo)

Indicates whether two FieldInfo objects are not equal.

Explicit Interface Implementations

_FieldInfo.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.

_FieldInfo.GetType()

Gets a Type object representing the FieldInfo type.

_FieldInfo.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can then be used to get the type information for an interface.

_FieldInfo.GetTypeInfoCount(UInt32)

Retrieves the number of type information interfaces that an object provides (either 0 or 1).

_FieldInfo.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.

Extension Methods

GetCustomAttribute(MemberInfo, Type)
GetCustomAttribute(MemberInfo, Type, Boolean)
GetCustomAttribute<T>(MemberInfo)
GetCustomAttribute<T>(MemberInfo, Boolean)
GetCustomAttributes(MemberInfo)
GetCustomAttributes(MemberInfo, Boolean)
GetCustomAttributes(MemberInfo, Type)
GetCustomAttributes(MemberInfo, Type, Boolean)
GetCustomAttributes<T>(MemberInfo)
GetCustomAttributes<T>(MemberInfo, Boolean)
IsDefined(MemberInfo, Type)
IsDefined(MemberInfo, Type, Boolean)
GetMetadataToken(MemberInfo)
HasMetadataToken(MemberInfo)

Thread Safety

This type is thread safe.