Type.FindMembers Method (MemberTypes, BindingFlags, MemberFilter, Object)

 

Returns a filtered array of MemberInfo objects of the specified member type.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

Public Overridable Function FindMembers (
	memberType As MemberTypes,
	bindingAttr As BindingFlags,
	filter As MemberFilter,
	filterCriteria As Object
) As MemberInfo()

Parameters

memberType
Type: System.Reflection.MemberTypes

An object that indicates the type of member to search for.

bindingAttr
Type: System.Reflection.BindingFlags

A bitmask comprised of one or more BindingFlags that specify how the search is conducted.

-or-

Zero, to return null.

filter
Type: System.Reflection.MemberFilter

The delegate that does the comparisons, returning true if the member currently being inspected matches the filterCriteria and false otherwise. You can use the FilterAttribute, FilterName, and FilterNameIgnoreCase delegates supplied by this class. The first uses the fields of FieldAttributes, MethodAttributes, and MethodImplAttributes as search criteria, and the other two delegates use String objects as the search criteria.

filterCriteria
Type: System.Object

The search criteria that determines whether a member is returned in the array of MemberInfo objects.

The fields of FieldAttributes, MethodAttributes, and MethodImplAttributes can be used in conjunction with the FilterAttribute delegate supplied by this class.

Return Value

Type: System.Reflection.MemberInfo()

A filtered array of MemberInfo objects of the specified member type.

-or-

An empty array of type MemberInfo, if the current Type does not have members of type memberType that match the filter criteria.

Exception Condition
ArgumentNullException

filter is null.

This method can be overridden by a derived class.

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

The following BindingFlags filter flags can be used to define which members to include in the search:

  • You must specify either BindingFlags.Instance or BindingFlags.Static in order to get a return.

  • Specify BindingFlags.Instance to include instance members in the search.

  • Specify BindingFlags.Static to include static members in the search.

  • Specify BindingFlags.Public to include public members in the search.

  • Specify BindingFlags.NonPublic to include non-public members (that is, private, internal, and protected members) in the search.

The following BindingFlags modifier flags can be used to change how the search works:

  • BindingFlags.DeclaredOnly to search only the members declared on the Type, not members that were simply inherited.

See System.Reflection.BindingFlags for more information.

Valid values for MemberType are defined in MemberInfo. If no such members are found, an empty array is returned.

To get the class initializer (.cctor) using this method, you must specify BindingFlags.Static | BindingFlags.NonPublic (BindingFlags.StaticOrBindingFlags.NonPublic in Visual Basic). You can also get the class initializer using the TypeInitializer property.

If the current Type represents a type parameter of a generic type or generic method, FindMembers processes any members declared by the class constraint and the interface constraints of the type parameter.

The following example finds all the members in a class that match the specified search criteria, and then displays the matched members.


Imports System
Imports System.Reflection
Imports Microsoft.VisualBasic

Class MyFindMembersClass

    Public Shared Sub Main()
        Dim objTest As New Object()
        Dim objType As Type = objTest.GetType()
        Dim arrayMemberInfo() As MemberInfo
        Try
            'Find all static or public methods in the Object 
            'class that match the specified name.
            arrayMemberInfo = objType.FindMembers(MemberTypes.Method, _
                              BindingFlags.Public Or BindingFlags.Static _
                              Or BindingFlags.Instance, _
                              New MemberFilter(AddressOf DelegateToSearchCriteria), _
                              "ReferenceEquals")

            Dim index As Integer
            For index = 0 To arrayMemberInfo.Length - 1
                Console.WriteLine("Result of FindMembers -" + ControlChars.Tab + _
                               arrayMemberInfo(index).ToString() + ControlChars.Cr)
            Next index
        Catch e As Exception
            Console.WriteLine("Exception : " + e.ToString())
        End Try
    End Sub 'Main

    Public Shared Function DelegateToSearchCriteria _
                            (ByVal objMemberInfo As MemberInfo, _
                             ByVal objSearch As Object) As Boolean
        ' Compare the name of the member function with the filter criteria.
        If objMemberInfo.Name.ToString() = objSearch.ToString() Then
            Return True
        Else
            Return False
        End If
    End Function 'DelegateToSearchCriteria 
End Class 'MyFindMembersClass

.NET Framework
Available since 1.1
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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