TypeAttributes Enum
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Specifies type attributes.
This enumeration supports a bitwise combination of its member values.
public enum class TypeAttributes
[System.Flags]
public enum TypeAttributes
[System.Flags]
[System.Serializable]
public enum TypeAttributes
[System.Flags]
[System.Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public enum TypeAttributes
[<System.Flags>]
type TypeAttributes =
[<System.Flags>]
[<System.Serializable>]
type TypeAttributes =
[<System.Flags>]
[<System.Serializable>]
[<System.Runtime.InteropServices.ComVisible(true)>]
type TypeAttributes =
Public Enum TypeAttributes
- Inheritance
- Attributes
Name | Value | Description |
---|---|---|
AnsiClass | 0 | LPTSTR is interpreted as ANSI. |
AutoLayout | 0 | Specifies that class fields are automatically laid out by the common language runtime. |
Class | 0 | Specifies that the type is a class. |
NotPublic | 0 | Specifies that the class is not public. |
Public | 1 | Specifies that the class is public. |
NestedPublic | 2 | Specifies that the class is nested with public visibility. |
NestedPrivate | 3 | Specifies that the class is nested with private visibility. |
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. |
NestedAssembly | 5 | Specifies that the class is nested with assembly visibility, and is thus accessible only by methods within its assembly. |
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. |
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. |
VisibilityMask | 7 | Specifies type visibility information. |
SequentialLayout | 8 | Specifies that class fields are laid out sequentially, in the order that the fields were emitted to the metadata. |
ExplicitLayout | 16 | Specifies that class fields are laid out at the specified offsets. |
LayoutMask | 24 | Specifies class layout information. |
ClassSemanticsMask | 32 | Specifies class semantics information; the current class is contextful (else agile). |
Interface | 32 | Specifies that the type is an interface. |
Abstract | 128 | Specifies that the type is abstract. |
Sealed | 256 | Specifies that the class is concrete and cannot be extended. |
SpecialName | 1024 | Specifies that the class is special in a way denoted by the name. |
RTSpecialName | 2048 | Runtime should check name encoding. |
Import | 4096 | Specifies that the class or interface is imported from another module. |
Serializable | 8192 | Specifies that the class can be serialized. |
WindowsRuntime | 16384 | Specifies a Windows Runtime type. |
UnicodeClass | 65536 | LPTSTR is interpreted as UNICODE. |
AutoClass | 131072 | LPTSTR is interpreted automatically. |
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. |
StringFormatMask | 196608 | Used to retrieve string information for native interoperability. |
HasSecurity | 262144 | Type has security associate with it. |
ReservedMask | 264192 | Attributes reserved for runtime use. |
BeforeFieldInit | 1048576 | Specifies that calling static methods of the type does not force the system to initialize the type. |
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. |
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
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 System.Reflection.TypeAttributes 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.
Prodotto | Versioni |
---|---|
.NET | Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9 |
.NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
.NET Standard | 1.0, 1.1, 1.2, 1.3, 1.4, 1.6, 2.0, 2.1 |
UWP | 10.0 |
Feedback su .NET
.NET è un progetto di open source. Selezionare un collegamento per fornire feedback: