Type.Attributes Properti
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Mendapatkan atribut yang terkait dengan Type.
public:
property System::Reflection::TypeAttributes Attributes { System::Reflection::TypeAttributes get(); };
public System.Reflection.TypeAttributes Attributes { get; }
member this.Attributes : System.Reflection.TypeAttributes
Public ReadOnly Property Attributes As TypeAttributes
Nilai Properti
Objek TypeAttributes yang mewakili set atribut , Typekecuali Type mewakili parameter jenis generik, dalam hal ini nilai tidak ditentukan.
Penerapan
Contoh
Contoh berikut menggunakan Attributes properti .
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
Keterangan
Beberapa anggota TypeAttributes enumerasi adalah masker yang mewakili sekelompok nilai. Setiap grup menyertakan satu anggota yang nilai mendasarnya adalah nol. Misalnya, nilai mendasar anggota TypeAttributes.NotPublic dalam TypeAttributes.VisibilityMask grup adalah nol, seperti halnya TypeAttributes.AutoLayout anggota dalam TypeAttributes.SequentialLayout grup. Karena itu, Anda harus menggunakan masker sebelum menguji nilai-nilai tersebut. Contoh memberikan ilustrasi.
Tip
Untuk sebagian besar tujuan, properti seperti IsClass,IsAutoLayout, dan IsSpecialName lebih mudah digunakan daripada atribut jenis.
Jika saat ini Type mewakili jenis generik yang dibangun, properti ini mengembalikan atribut definisi jenis generik. Misalnya, atribut yang dikembalikan untuk MyGenericClass<int> (MyGenericClass(Of Integer) di Visual Basic) adalah atribut dari MyGenericClass<T> (MyGenericClass(Of T) di Visual Basic).
Jika saat ini Type mewakili parameter jenis generik - yaitu, jika IsGenericParameter properti mengembalikan true - TypeAttributes nilai yang dikembalikan oleh properti ini tidak ditentukan.