FieldInfo Class

Definition

Namespace:

System.Reflection

Assembly:

System.Runtime.dll

Source:

FieldInfo.cs

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

public ref class FieldInfo abstract : System::Reflection::MemberInfo

public abstract class FieldInfo : System.Reflection.MemberInfo

type FieldInfo = class
    inherit MemberInfo

Public MustInherit Class FieldInfo
Inherits MemberInfo

Inheritance

Object

MemberInfo

FieldInfo

Derived

Microsoft.JScript.COMFieldInfo

Microsoft.JScript.JSField

Microsoft.JScript.JSFieldInfo

System.Reflection.Emit.FieldBuilder

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.Reflection

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.

Notes to Implementers

When you inherit from FieldInfo, you must override the following members: GetValue(Object) and SetValue(Object, Object, BindingFlags, Binder, CultureInfo).

Constructors

FieldInfo()

Initializes a new instance of the FieldInfo class.

Properties

Attributes	Gets the attributes associated with this field.
CustomAttributes	Gets a collection that contains this member's custom attributes. (Inherited from MemberInfo)
DeclaringType	Gets the class that declares this member. (Inherited from MemberInfo)
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.
IsCollectible	Gets a value that indicates whether this MemberInfo object is part of an assembly held in a collectible AssemblyLoadContext. (Inherited from MemberInfo)
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	Obsolete. 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.
MetadataToken	Gets a value that identifies a metadata element. (Inherited from MemberInfo)
Module	Gets the module in which the type that declares the member represented by the current MemberInfo is defined. (Inherited from MemberInfo)
Name	Gets the name of the current member. (Inherited from MemberInfo)
ReflectedType	Gets the class object that was used to obtain this instance of MemberInfo. (Inherited from MemberInfo)

Methods

Equals(Object)	Returns a value that indicates whether this instance is equal to a specified object.
GetCustomAttributes(Boolean)	When overridden in a derived class, returns an array of all custom attributes applied to this member. (Inherited from MemberInfo)
GetCustomAttributes(Type, Boolean)	When overridden in a derived class, returns an array of custom attributes applied to this member and identified by Type. (Inherited from MemberInfo)
GetCustomAttributesData()	Returns a list of CustomAttributeData objects representing data about the attributes that have been applied to the target member. (Inherited from MemberInfo)
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.
GetModifiedFieldType()	Gets the modified type of this field object.
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.
GetType()	Discovers the attributes of a member and provides access to member metadata. (Inherited from MemberInfo)
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.
HasSameMetadataDefinitionAs(MemberInfo)	(Inherited from MemberInfo)
IsDefined(Type, Boolean)	When overridden in a derived class, indicates whether one or more attributes of the specified type or of its derived types is applied to this member. (Inherited from MemberInfo)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from 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.
ToString()	Returns a string that represents the current object. (Inherited from Object)

Operators

Equality(FieldInfo, FieldInfo)	Indicates whether two FieldInfo objects are equal.
Inequality(FieldInfo, FieldInfo)	Indicates whether two FieldInfo objects are not equal.

Extension Methods

GetCustomAttribute(MemberInfo, Type)	Retrieves a custom attribute of a specified type that is applied to a specified member.
GetCustomAttribute(MemberInfo, Type, Boolean)	Retrieves a custom attribute of a specified type that is applied to a specified member, and optionally inspects the ancestors of that member.
GetCustomAttribute<T>(MemberInfo)	Retrieves a custom attribute of a specified type that is applied to a specified member.
GetCustomAttribute<T>(MemberInfo, Boolean)	Retrieves a custom attribute of a specified type that is applied to a specified member, and optionally inspects the ancestors of that member.
GetCustomAttributes(MemberInfo)	Retrieves a collection of custom attributes that are applied to a specified member.
GetCustomAttributes(MemberInfo, Boolean)	Retrieves a collection of custom attributes that are applied to a specified member, and optionally inspects the ancestors of that member.
GetCustomAttributes(MemberInfo, Type)	Retrieves a collection of custom attributes of a specified type that are applied to a specified member.
GetCustomAttributes(MemberInfo, Type, Boolean)	Retrieves a collection of custom attributes of a specified type that are applied to a specified member, and optionally inspects the ancestors of that member.
GetCustomAttributes<T>(MemberInfo)	Retrieves a collection of custom attributes of a specified type that are applied to a specified member.
GetCustomAttributes<T>(MemberInfo, Boolean)	Retrieves a collection of custom attributes of a specified type that are applied to a specified member, and optionally inspects the ancestors of that member.
IsDefined(MemberInfo, Type)	Indicates whether custom attributes of a specified type are applied to a specified member.
IsDefined(MemberInfo, Type, Boolean)	Indicates whether custom attributes of a specified type are applied to a specified member, and, optionally, applied to its ancestors.
GetMetadataToken(MemberInfo)	Gets a metadata token for the given member, if available.
HasMetadataToken(MemberInfo)	Returns a value that indicates whether a metadata token is available for the specified member.

Thread Safety

This type is thread safe.

See also

• Type