TypeAttributes TypeAttributes TypeAttributes TypeAttributes Enum

Definition

Specifies type attributes.

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

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

Fields

Abstract Abstract Abstract Abstract 128

Specifies that the type is abstract.

AnsiClass AnsiClass AnsiClass AnsiClass 0

LPTSTR is interpreted as ANSI.

AutoClass AutoClass AutoClass AutoClass 131072

LPTSTR is interpreted automatically.

AutoLayout AutoLayout AutoLayout AutoLayout 0

Specifies that class fields are automatically laid out by the common language runtime.

BeforeFieldInit BeforeFieldInit BeforeFieldInit BeforeFieldInit 1048576

Specifies that calling static methods of the type does not force the system to initialize the type.

Class Class Class Class 0

Specifies that the type is a class.

ClassSemanticsMask ClassSemanticsMask ClassSemanticsMask ClassSemanticsMask 32

Specifies class semantics information; the current class is contextful (else agile).

CustomFormatClass CustomFormatClass CustomFormatClass CustomFormatClass 196608

LPSTR is interpreted by some implementation-specific means, which includes the possibility of throwing a NotSupportedException. Not used in the Microsoft implementation of the .NET Framework.

CustomFormatMask CustomFormatMask CustomFormatMask CustomFormatMask 12582912

Used to retrieve non-standard encoding information for native interop. The meaning of the values of these 2 bits is unspecified. Not used in the Microsoft implementation of the .NET Framework.

ExplicitLayout ExplicitLayout ExplicitLayout ExplicitLayout 16

Specifies that class fields are laid out at the specified offsets.

HasSecurity HasSecurity HasSecurity HasSecurity 262144

Type has security associate with it.

Import Import Import Import 4096

Specifies that the class or interface is imported from another module.

Interface Interface Interface Interface 32

Specifies that the type is an interface.

LayoutMask LayoutMask LayoutMask LayoutMask 24

Specifies class layout information.

NestedAssembly NestedAssembly NestedAssembly NestedAssembly 5

Specifies that the class is nested with assembly visibility, and is thus accessible only by methods within its assembly.

NestedFamANDAssem NestedFamANDAssem NestedFamANDAssem NestedFamANDAssem 6

Specifies that the class is nested with assembly and family visibility, and is thus accessible only by methods lying in the intersection of its family and assembly.

NestedFamily NestedFamily NestedFamily NestedFamily 4

Specifies that the class is nested with family visibility, and is thus accessible only by methods within its own type and any derived types.

NestedFamORAssem NestedFamORAssem NestedFamORAssem NestedFamORAssem 7

Specifies that the class is nested with family or assembly visibility, and is thus accessible only by methods lying in the union of its family and assembly.

NestedPrivate NestedPrivate NestedPrivate NestedPrivate 3

Specifies that the class is nested with private visibility.

NestedPublic NestedPublic NestedPublic NestedPublic 2

Specifies that the class is nested with public visibility.

NotPublic NotPublic NotPublic NotPublic 0

Specifies that the class is not public.

Public Public Public Public 1

Specifies that the class is public.

ReservedMask ReservedMask ReservedMask ReservedMask 264192

Attributes reserved for runtime use.

RTSpecialName RTSpecialName RTSpecialName RTSpecialName 2048

Runtime should check name encoding.

Sealed Sealed Sealed Sealed 256

Specifies that the class is concrete and cannot be extended.

SequentialLayout SequentialLayout SequentialLayout SequentialLayout 8

Specifies that class fields are laid out sequentially, in the order that the fields were emitted to the metadata.

Serializable Serializable Serializable Serializable 8192

Specifies that the class can be serialized.

SpecialName SpecialName SpecialName SpecialName 1024

Specifies that the class is special in a way denoted by the name.

StringFormatMask StringFormatMask StringFormatMask StringFormatMask 196608

Used to retrieve string information for native interoperability.

UnicodeClass UnicodeClass UnicodeClass UnicodeClass 65536

LPTSTR is interpreted as UNICODE.

VisibilityMask VisibilityMask VisibilityMask VisibilityMask 7

Specifies type visibility information.

WindowsRuntime WindowsRuntime WindowsRuntime WindowsRuntime 16384

Specifies a Windows Runtime type.

Examples

The following example retrieves the value of the Attributes property for Type objects that represent a number of different types, and then determines whether individual attribute flags have been set.

using System;
using System.Reflection;

internal struct S
{
    public int X;
}

public abstract class Example
{
    protected sealed class NestedClass {}

    public interface INested {}

    public static void Main()
    {
        // Create an array of types.
        Type[] types = { typeof(Example), typeof(NestedClass),
                         typeof(INested), typeof(S) };

        foreach (var t in types) 
        {
           Console.WriteLine("Attributes for type {0}:", t.Name);

           TypeAttributes attr = t.Attributes;

           // To test for visibility attributes, you must use the visibility mask.
           TypeAttributes visibility = attr & TypeAttributes.VisibilityMask;
           switch (visibility)
           {
               case TypeAttributes.NotPublic:
                   Console.WriteLine("   ...is not public");
                   break;
               case TypeAttributes.Public:
                   Console.WriteLine("   ...is public");
                   break;
               case TypeAttributes.NestedPublic:
                   Console.WriteLine("   ...is nested and public");
                   break;
               case TypeAttributes.NestedPrivate:
                   Console.WriteLine("   ...is nested and private");
                   break;
               case TypeAttributes.NestedFamANDAssem:
                   Console.WriteLine("   ...is nested, and inheritable only within the assembly" +
                      "\n         (cannot be declared in C#)");
                   break;
               case TypeAttributes.NestedAssembly:
                   Console.WriteLine("   ...is nested and internal");
                   break;
               case TypeAttributes.NestedFamily:
                   Console.WriteLine("   ...is nested and protected");
                   break;
               case TypeAttributes.NestedFamORAssem:
                   Console.WriteLine("   ...is nested and protected internal");
                   break;
           }

           // Use the layout mask to test for layout attributes.
           TypeAttributes layout = attr & TypeAttributes.LayoutMask;
           switch (layout)
           {
               case TypeAttributes.AutoLayout:
                   Console.WriteLine("   ...is AutoLayout");
                   break;
               case TypeAttributes.SequentialLayout:
                   Console.WriteLine("   ...is SequentialLayout");
                   break;
               case TypeAttributes.ExplicitLayout:
                   Console.WriteLine("   ...is ExplicitLayout");
                   break;
           }

           // Use the class semantics mask to test for class semantics attributes.
           TypeAttributes classSemantics = attr & TypeAttributes.ClassSemanticsMask;
           switch (classSemantics)
           {
               case TypeAttributes.Class:
                   if (t.IsValueType)
                   {
                       Console.WriteLine("   ...is a value type");
                   }
                   else
                   {
                       Console.WriteLine("   ...is a class");
                   }
                   break;
               case TypeAttributes.Interface:
                   Console.WriteLine("   ...is an interface");
                   break;
           }

           if ((attr & TypeAttributes.Abstract) != 0)
           {
               Console.WriteLine("   ...is abstract");
           }

           if ((attr & TypeAttributes.Sealed) != 0)
           {
               Console.WriteLine("   ...is sealed");
           }
           
           Console.WriteLine();
       }
    }
}
// The example displays the following output:
// Attributes for type Example:
//    ...is public
//    ...is AutoLayout
//    ...is a class
//    ...is abstract

// Attributes for type NestedClass:
//    ...is nested and protected
//    ...is AutoLayout
//    ...is a class
//    ...is sealed

// Attributes for type INested:
//    ...is nested and public
//    ...is AutoLayout
//    ...is an interface
//    ...is abstract

// Attributes for type S:
//    ...is not public
//    ...is SequentialLayout
//    ...is a value type
//    ...is sealed
Imports System.Reflection

Friend Structure S
    Public X As Integer
End Structure

Public MustInherit Class Example
    Protected NotInheritable Class NestedClass
    End Class

    Public Interface INested
    End Interface

    Public Shared Sub Main()
        ' Create an array of types.
        Dim types() As Type = { GetType(Example), GetType(NestedClass),
                                GetType(INested), GetType(S) }

        For Each t In types
           Console.WriteLine("Attributes for type {0}:", t.Name)

           Dim attr As TypeAttributes = t.Attributes

           ' Use the visibility mask to test for visibility attributes.
           Dim visibility As TypeAttributes = attr And TypeAttributes.VisibilityMask
           Select Case visibility
               Case TypeAttributes.NotPublic:
                   Console.WriteLine("   ...is not Public")
               Case TypeAttributes.Public:
                   Console.WriteLine("   ...is Public")
               Case TypeAttributes.NestedPublic:
                   Console.WriteLine("   ...is nested and Public")
               Case TypeAttributes.NestedPrivate:
                   Console.WriteLine("   ...is nested and Private")
               Case TypeAttributes.NestedFamANDAssem:
                   Console.WriteLine("   ...is nested, and inheritable only within the assembly" & _
                      vbLf & "         (cannot be declared in Visual Basic)")
               Case TypeAttributes.NestedAssembly:
                   Console.WriteLine("   ...is nested and Friend")
               Case TypeAttributes.NestedFamily:
                   Console.WriteLine("   ...is nested and Protected")
               Case TypeAttributes.NestedFamORAssem:
                   Console.WriteLine("   ...is nested and Protected Friend")
           End Select

           ' Use the layout mask to test for layout attributes.
           Dim layout As TypeAttributes = attr And TypeAttributes.LayoutMask
           Select Case layout
               Case TypeAttributes.AutoLayout:
                   Console.WriteLine("   ...is AutoLayout")
               Case TypeAttributes.SequentialLayout:
                   Console.WriteLine("   ...is SequentialLayout")
               Case TypeAttributes.ExplicitLayout:
                   Console.WriteLine("   ...is ExplicitLayout")
           End Select

           ' Use the class semantics mask to test for class semantics attributes.
           Dim classSemantics As TypeAttributes = attr And TypeAttributes.ClassSemanticsMask
           Select Case classSemantics
               Case TypeAttributes.Class:
                   If t.IsValueType Then
                       Console.WriteLine("   ...is a value type")
                   Else
                       Console.WriteLine("   ...is a class")
                   End If
               Case TypeAttributes.Interface:
                   Console.WriteLine("   ...is an interface")
           End Select

           If 0 <> (attr And TypeAttributes.Abstract) Then _
               Console.WriteLine("   ...is MustInherit")

           If 0 <> (attr And TypeAttributes.Sealed) Then _
               Console.WriteLine("   ...is NotInheritable")
           Console.WriteLine()
       Next
    End Sub
End Class
' The example displays the following output:
'       Attributes for type Example:
'          ...is Public
'          ...is AutoLayout
'          ...is a class
'          ...is MustInherit
'
'       Attributes for type NestedClass:
'          ...is nested and Protected
'          ...is AutoLayout
'          ...is a class
'          ...is NotInheritable
'
'       Attributes for type INested:
'          ...is nested and Public
'          ...is AutoLayout
'          ...is an interface
'          ...is MustInherit
'
'       Attributes for type S:
'          ...is not Public
'          ...is SequentialLayout
'          ...is a value type
'          ...is NotInheritable

Remarks

Some of the members of the TypeAttributes enumeration are masks that represent a set of mutually exclusive attributes. For example, the VisibilityMask member includes the NotPublic, Public, NestedPublic, NestedPrivate, NestedFamily, NestedAssembly, NestedFamANDAssem, and NestedFamORAssem members, Because each attribute set includes a member whose underlying value is zero, you should first And the value of the mask with the specific TypeAttributes.VisibilityMask value retrieved from a property such as Type.Attributes. The following table lists the masks and the individual members that they include:

Mask Includes
VisibilityMask NotPublic
Public
NestedPublic
NestedPrivate
NestedFamily
NestedAssembly
NestedFamANDAssem
NestedFamORAssem
LayoutMask AutoLayout
SequentialLayout
ExplicitLayout
ClassSemanticsMask Class
Interface
StringFormatMask AnsiClass
UnicodeClass
AutoClass
CustomFormatClass
CustomFormatMask No members.

The members of this enumerator class match the CorTypeAttr enumerator as defined in the corhdr.h file.

Applies to