Type.GetDefaultMembers 方法

定義

搜尋定義給目前 Type 的成員,而它的 DefaultMemberAttribute 已設定。Searches for the members defined for the current Type whose DefaultMemberAttribute is set.

public:
 virtual cli::array <System::Reflection::MemberInfo ^> ^ GetDefaultMembers();
public virtual System.Reflection.MemberInfo[] GetDefaultMembers ();
abstract member GetDefaultMembers : unit -> System.Reflection.MemberInfo[]
override this.GetDefaultMembers : unit -> System.Reflection.MemberInfo[]
Public Overridable Function GetDefaultMembers () As MemberInfo()

傳回

MemberInfo[]

MemberInfo 物件的陣列,代表目前 Type 的所有預設成員。An array of MemberInfo objects representing all default members of the current Type.

-或--or- MemberInfo 類型的空陣列 (如果目前 Type 沒有預設成員)。An empty array of type MemberInfo, if the current Type does not have default members.

實作

範例

下列範例會取得的預設成員資訊 MyClass ,並顯示預設成員。The following example obtains the default member information of MyClass and displays the default members.

using namespace System;
using namespace System::Reflection;
using namespace System::IO;

[DefaultMemberAttribute("Age")]
public ref class MyClass
{
public:
   void Name( String^ s ){}


   property int Age 
   {
      int get()
      {
         return 20;
      }

   }

};

int main()
{
   try
   {
      Type^ myType = MyClass::typeid;
      array<MemberInfo^>^memberInfoArray = myType->GetDefaultMembers();
      if ( memberInfoArray->Length > 0 )
      {
         System::Collections::IEnumerator^ myEnum = memberInfoArray->GetEnumerator();
         while ( myEnum->MoveNext() )
         {
            MemberInfo^ memberInfoObj = safe_cast<MemberInfo^>(myEnum->Current);
            Console::WriteLine( "The default member name is: {0}", memberInfoObj );
         }
      }
      else
      {
         Console::WriteLine( "No default members are available." );
      }
   }
   catch ( InvalidOperationException^ e ) 
   {
      Console::WriteLine( "InvalidOperationException: {0}", e->Message );
   }
   catch ( IOException^ e ) 
   {
      Console::WriteLine( "IOException: {0}", e->Message );
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception: {0}", e->Message );
   }
}

using System;
using System.Reflection;
using System.IO;

[DefaultMemberAttribute("Age")]
public class MyClass
{
    public void Name(String s) {}
    public int Age
    {
        get
        {
            return 20;
        }
    }
    public static void Main()
    {
        try
        {
            Type  myType = typeof(MyClass);
            MemberInfo[] memberInfoArray = myType.GetDefaultMembers();
            if (memberInfoArray.Length > 0)
            {
                foreach(MemberInfo memberInfoObj in memberInfoArray)
                {
                    Console.WriteLine("The default member name is: " + memberInfoObj.ToString());
                }
            }
            else
            {
                Console.WriteLine("No default members are available.");
            }
        }
        catch(InvalidOperationException e)
        {
            Console.WriteLine("InvalidOperationException: " + e.Message);
        }
        catch(IOException e)
        {
            Console.WriteLine("IOException: " + e.Message);
        }
        catch(Exception e)
        {
            Console.WriteLine("Exception: " + e.Message);
        }
    }
}
Imports System.Reflection
Imports System.IO

<DefaultMemberAttribute("Age")> Public Class [MyClass]

    Public Sub Name(ByVal s As String)
    End Sub

    Public ReadOnly Property Age() As Integer
        Get
            Return 20
        End Get
    End Property

    Public Shared Sub Main()
        Try
            Dim myType As Type = GetType([MyClass])
            Dim memberInfoArray As MemberInfo() = myType.GetDefaultMembers()
            If memberInfoArray.Length > 0 Then
                Dim memberInfoObj As MemberInfo
                For Each memberInfoObj In memberInfoArray
                    Console.WriteLine("The default member name is: " + memberInfoObj.ToString())
                Next memberInfoObj
            Else
                Console.WriteLine("No default members are available.")
            End If
        Catch e As InvalidOperationException
            Console.WriteLine("InvalidOperationException: " + e.Message)
        Catch e As IOException
            Console.WriteLine("IOException: " + e.Message)
        Catch e As Exception
            Console.WriteLine("Exception: " + e.Message)
        End Try
    End Sub
End Class

備註

GetDefaultMembers方法不會以特定順序傳回成員,例如字母順序或宣告順序。The GetDefaultMembers method does not return members in a particular order, such as alphabetical or declaration order. 您的程式碼不得相依于傳回成員的順序,因為該順序會有所不同。Your code must not depend on the order in which members are returned, because that order varies.

衍生類別可以覆寫這個方法。This method can be overridden by a derived class.

成員包括屬性、方法、欄位、事件等等。Members include properties, methods, fields, events, and so on.

下表顯示在反映型別時,方法會傳回基類的成員 GetThe following table shows what members of a base class are returned by the Get methods when reflecting on a type.

成員類型Member Type StaticStatic 非靜態Non-Static
建構函式Constructor No No
欄位Field No 可以。Yes. 欄位一律會依名稱和簽章進行隱藏。A field is always hide-by-name-and-signature.
事件Event 不適用Not applicable 一般類型系統規則是,繼承與實作為屬性的方法相同。The common type system rule is that the inheritance is the same as that of the methods that implement the property. 反映會將屬性視為隱藏名稱和簽章。Reflection treats properties as hide-by-name-and-signature. 請參閱下面的附注2。See note 2 below.
方法Method No 可以。Yes. (虛擬和非虛擬) 的方法都可以依名稱或依名稱、依名稱和簽章來隱藏。A method (both virtual and non-virtual) can be hide-by-name or hide-by-name-and-signature.
巢狀型別Nested Type No No
屬性Property 不適用Not applicable 一般類型系統規則是,繼承與實作為屬性的方法相同。The common type system rule is that the inheritance is the same as that of the methods that implement the property. 反映會將屬性視為隱藏名稱和簽章。Reflection treats properties as hide-by-name-and-signature. 請參閱下面的附注2。See note 2 below.
  1. 依名稱和簽章會考慮簽章的所有部分,包括自訂修飾詞、傳回類型、參數類型、個 sentinel 和非受控呼叫慣例。Hide-by-name-and-signature considers all of the parts of the signature, including custom modifiers, return types, parameter types, sentinels, and unmanaged calling conventions. 這是二進位比較。This is a binary comparison.

  2. 針對反映,屬性和事件會依名稱和簽章來隱藏。For reflection, properties and events are hide-by-name-and-signature. 如果您的屬性同時具有基類中的 get 和 set 存取子,但衍生類別只有 get 存取子,則衍生類別屬性會隱藏基類屬性,而且您將無法存取基類的 setter。If you have a property with both a get and a set accessor in the base class, but the derived class has only a get accessor, the derived class property hides the base class property, and you will not be able to access the setter on the base class.

  3. 自訂屬性不是一般型別系統的一部分。Custom attributes are not part of the common type system.

如果目前的 Type 代表結構化泛型型別,這個方法會傳回 MemberInfo 類型參數取代為適當類型引數的物件。If the current Type represents a constructed generic type, this method returns the MemberInfo objects with the type parameters replaced by the appropriate type arguments. 例如,如果類別具有傳回的 C<T> 屬性 P ,則在 T Visual Basic) 中,會在 GetDefaultMembers C<int> int P c # (Property P As Integer 中呼叫。For example, if class C<T> has a property P that returns T, calling GetDefaultMembers on C<int> returns int P in C# (Property P As Integer in Visual Basic).

如果目前 Type 表示泛型型別或泛型方法定義中的類型參數,這個方法會搜尋類別條件約束的成員, Object 如果沒有類別條件約束,則會搜尋的成員。If the current Type represents a type parameter in the definition of a generic type or generic method, this method searches the members of the class constraint, or the members of Object if there is no class constraint.

適用於

另請參閱