Type.Attributes Property
Definition
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.
Gets the attributes associated with the Type.
public:
property System::Reflection::TypeAttributes Attributes { System::Reflection::TypeAttributes get(); };public System.Reflection.TypeAttributes Attributes { get; }member this.Attributes : System.Reflection.TypeAttributesPublic ReadOnly Property Attributes As TypeAttributesProperty Value
A TypeAttributes object representing the attribute set of the Type, unless the Type represents a generic type parameter, in which case the value is unspecified.
Implements
Examples
The following example uses the Attributes property.
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 members of the TypeAttributes enumeration are masks that represent a group of values. Each group includes one member whose underlying value is zero. For example, the underlying value of the TypeAttributes.NotPublic member in the TypeAttributes.VisibilityMask group is zero, as is the TypeAttributes.AutoLayout member in the TypeAttributes.SequentialLayout group. Because of this, you must use the mask before testing for those values. The example provides an illustration.
Tip
For most purposes, properties like IsClass,IsAutoLayout, and IsSpecialName are easier to use than type attributes.
If the current Type represents a constructed generic type, this property returns the attributes of the generic type definition. For example, the attributes returned for MyGenericClass<int> (MyGenericClass(Of Integer) in Visual Basic) are the attributes of MyGenericClass<T> (MyGenericClass(Of T) in Visual Basic).
If the current Type represents a generic type parameter - that is, if the IsGenericParameter property returns true - the TypeAttributes value returned by this property is unspecified.
Applies to
See also
.NET