Export (0) Print
Expand All
This topic has not yet been rated - Rate this topic

Type.GetDefaultMembers Method

Searches for the members defined for the current Type whose DefaultMemberAttribute is set.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)
public virtual MemberInfo[] GetDefaultMembers()

Return Value

Type: System.Reflection.MemberInfo[]
An array of MemberInfo objects representing all default members of the current Type.
-or-
An empty array of type MemberInfo, if the current Type does not have default members.

The GetDefaultMembers method does not return members in a particular order, such as alphabetical or declaration order. Your code must not depend on the order in which members are returned, because that order varies.

This method can be overridden by a derived class.

Members include properties, methods, fields, events, and so on.

The following table shows what members of a base class are returned by the Get methods when reflecting on a type.

Member Type

Static

Non-Static

Constructor

No

No

Field

No

Yes. A field is always hide-by-name-and-signature.

Event

Not applicable

The common type system rule is that the inheritance is the same as that of the methods that implement the property. Reflection treats properties as hide-by-name-and-signature. See note 2 below.

Method

No

Yes. A method (both virtual and non-virtual) can be hide-by-name or hide-by-name-and-signature.

Nested Type

No

No

Property

Not applicable

The common type system rule is that the inheritance is the same as that of the methods that implement the property. Reflection treats properties as hide-by-name-and-signature. See note 2 below.

Notes:

  1. 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. This is a binary comparison.

  2. For reflection, properties and events are hide-by-name-and-signature. 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. Custom attributes are not part of the common type system.

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. 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).

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.

The following example obtains the default member information of MyClass and displays the default members.



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

[DefaultMemberAttribute("Age")]
public class Example
{
   public void Name(String s) { }
   public int Age
   {
      get
      {
         return 20;
      }
   }
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      try
      {
         Type myType = typeof(Example);
         MemberInfo[] memberInfoArray = myType.GetDefaultMembers();
         if (memberInfoArray.Length > 0)
         {
            foreach (MemberInfo memberInfoObj in memberInfoArray)
            {
               outputBlock.Text += "The default member name is: " + memberInfoObj.ToString() + "\n";
            }
         }
         else
         {
            outputBlock.Text += "No default members are available." + "\n";
         }
      }
      catch (InvalidOperationException e)
      {
         outputBlock.Text += "InvalidOperationException: " + e.Message + "\n";
      }
      catch (IOException e)
      {
         outputBlock.Text += "IOException: " + e.Message + "\n";
      }
      catch (Exception e)
      {
         outputBlock.Text += "Exception: " + e.Message + "\n";
      }
   }
}


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

Did you find this helpful?
(1500 characters remaining)
Thank you for your feedback

Community Additions

ADD
Show:
© 2014 Microsoft. All rights reserved.