Imports System
Imports System.Reflection

Module DemoModule

    ' A custom attribute to allow 2 authors per method.
    <AttributeUsage(AttributeTargets.Method)> _
    Public Class AuthorsAttribute
        Inherits Attribute

        Public Sub New(ByVal name1 As String, ByVal name2 As String)
            myAuthorName1 = name1
            myAuthorName2 = name2
        End Sub 

        Protected myAuthorName1 As String 
        Protected myAuthorName2 As String 

        Public Property AuthorName1() As String 
            Get 
                Return myAuthorName1
            End Get 
            Set(ByVal Value As String)
                myAuthorName1 = AuthorName1
            End Set 
        End Property 

        Public Property AuthorName2() As String 
            Get 
                Return myAuthorName2
            End Get 
            Set(ByVal Value As String)
                myAuthorName2 = AuthorName2
            End Set 
        End Property 

        ' Use the hash code of the string objects and xor them together. 
        Public Overrides Function GetHashCode() As Integer 
            Return myAuthorName1.GetHashCode() Xor myAuthorName2.GetHashCode()
        End Function 

        ' Determine if the object is a match to this one. 
        Public Overrides Function Match(ByVal obj As Object) As Boolean 
            ' Obviously a match. 
            If obj Is Me Then 
                Return True 
            End If 

            ' Obviously we're not nothing, so no. 
            If obj Is Nothing Then 
                Return False 
            End If 

            If TypeOf obj Is AuthorsAttribute Then 
                ' Combine the hash codes and see if they're unchanged. 
                Dim authObj As AuthorsAttribute = CType(obj, AuthorsAttribute)
                Dim firstHash As Integer = authObj.GetHashCode() And GetHashCode()
                If firstHash = GetHashCode() Then 
                    Return True 
                Else 
                    Return False 
                End If 
            Else 
                Return False 
            End If 
        End Function 

    End Class 

    ' Add some authors to methods of a class. 
    Public Class TestClass1
        <Authors("William Shakespeare", "Herman Melville")> _
        Public Sub Method1()
        End Sub

        <Authors("Leo Tolstoy", "John Milton")> _
        Public Sub Method2()
        End Sub 
    End Class 

    ' Add authors to a second class's methods. 
    Public Class TestClass2
        <Authors("William Shakespeare", "Herman Melville")> _
        Public Sub Method1()
        End Sub

        <Authors("Leo Tolstoy", "John Milton")> _
        Public Sub Method2()
        End Sub

        <Authors("Francis Bacon", "Miguel Cervantes")> _
        Public Sub Method3()
        End Sub 
    End Class 

    Sub Main()
        ' Get the type for both classes to access their metadata. 
        Dim clsType1 As Type = GetType(TestClass1)
        Dim clsType2 As Type = GetType(TestClass2)

        Dim mInfo1 As MethodInfo
        ' Iterate through each method of the first class. 
        For Each mInfo1 In clsType1.GetMethods()
            ' Check each method for the Authors attribute. 
            Dim attr1 As Attribute = Attribute.GetCustomAttribute(mInfo1, _
                GetType(AuthorsAttribute))
            If Not attr1 Is Nothing And TypeOf attr1 Is AuthorsAttribute Then 
                Dim authAttr1 As AuthorsAttribute = _
                    CType(attr1, AuthorsAttribute)
                ' Display the authors.
                Console.WriteLine("Method {0} was authored by {1} and {2}.", _
                                mInfo1.Name, authAttr1.AuthorName1, _
                                authAttr1.AuthorName2)
                Dim mInfo2 As MethodInfo
                ' Iterate through each method of the second class. 
                For Each mInfo2 In clsType2.GetMethods()
                    ' Check each method for the Authors attribute. 
                    Dim attr2 As Attribute = Attribute.GetCustomAttribute( _
                        mInfo2, GetType(AuthorsAttribute))
                    If Not attr2 Is Nothing And _
                        TypeOf attr2 Is AuthorsAttribute Then 
                        Dim authAttr2 As AuthorsAttribute = _
                            CType(attr2, AuthorsAttribute)
                        ' Compare with the authors in the first class. 
                        If authAttr2.Match(authAttr1) = True Then
                            Console.WriteLine("Method {0} in class {1} was " + _
                                        "also authored by the same team.", _
                                        mInfo2.Name, clsType2.Name)
                        End If 
                    End If 
                Next
                Console.WriteLine("")
            End If 
        Next 
    End Sub 
End Module 

' Output: 
' Method Method1 was authored by William Shakespeare and Herman Melville. 
' Method Method1 in class TestClass2 was also authored by the same team. 
'  
' Method Method2 was authored by Leo Tolstoy and John Milton. 
' Method Method2 in class TestClass2 was also authored by the same team.

using System;
using System.Reflection;

namespace MatchCS {
	// A custom attribute to allow 2 authors per method. 
	public class AuthorsAttribute : Attribute {
		public AuthorsAttribute(string name1, string name2) {
			authorName1 = name1;
			authorName2 = name2;
		}

		protected string authorName1;
		protected string authorName2;
	
		public string AuthorName1 {
			get { return authorName1; }
			set { authorName1 = AuthorName1; }
		}

		public string AuthorName2 {
			get { return authorName2; }
			set { authorName2 = AuthorName2; }
		}

		// Use the hash code of the string objects and xor them together. 
		public override int GetHashCode() {
			return authorName1.GetHashCode() ^ authorName2.GetHashCode();
		}

		// Determine if the object is a match to this one. 
		public override bool Match(object obj) {
			// Obviously a match. 
			if (obj == this)
				return true;

			// Obviously we're not null, so no. 
			if (obj == null)
				return false;

			if (obj is AuthorsAttribute)
				// Combine the hash codes and see if they're unchanged. 
				return (((AuthorsAttribute)obj).GetHashCode() & GetHashCode())
					== GetHashCode();
			else 
				return false;
		}
	}

	// Add some authors to methods of a class. 
	public class TestClass1 {
		[Authors("William Shakespeare", "Herman Melville")]
		public void Method1()
		{}

		[Authors("Leo Tolstoy", "John Milton")]
		public void Method2()
		{}
	}

	// Add authors to a second class's methods. 
	public class TestClass2 {
		[Authors("William Shakespeare", "Herman Melville")]
		public void Method1()
		{}

		[Authors("Leo Tolstoy", "John Milton")]
		public void Method2()
		{}

		[Authors("William Shakespeare", "John Milton")]
		public void Method3()
		{}
	}

	class DemoClass {
		static void Main(string[] args) {
			// Get the type for both classes to access their metadata.
			Type clsType1 = typeof(TestClass1);
			Type clsType2 = typeof(TestClass2);

			// Iterate through each method of the first class. 
			foreach(MethodInfo mInfo1 in clsType1.GetMethods()) {
				// Check each method for the Authors attribute.
				AuthorsAttribute authAttr1 = (AuthorsAttribute)
					Attribute.GetCustomAttribute(mInfo1, 
					typeof(AuthorsAttribute));
				if (authAttr1 != null) {
					// Display the authors.
					Console.WriteLine("Method {0} was authored by {1} " +
										"and {2}.", mInfo1.Name, 
										authAttr1.AuthorName1, 
										authAttr1.AuthorName2);
					// Iterate through each method of the second class. 
					foreach(MethodInfo mInfo2 in clsType2.GetMethods()) {
						// Check each method for the Authors attribute.
						AuthorsAttribute authAttr2 = (AuthorsAttribute)
							Attribute.GetCustomAttribute(mInfo2, 
							typeof(AuthorsAttribute));
						// Compare with the authors in the first class. 
						if (authAttr2 != null && authAttr2.Match(authAttr1))
							Console.WriteLine("Method {0} in class {1} " +
								"was authored by the same team.",
								mInfo2.Name, clsType2.Name);
					}
					Console.WriteLine("");
				}
			}
		}
	}
}

/*
 * Output:
 * Method Method1 was authored by William Shakespeare and Herman Melville.
 * Method Method1 in class TestClass2 was authored by the same team.
 *
 * Method Method2 was authored by Leo Tolstoy and John Milton.
 * Method Method2 in class TestClass2 was authored by the same team.
 */

using namespace System;
using namespace System::Reflection;

// A custom attribute to allow 2 authors per method. 
public ref class AuthorsAttribute: public Attribute
{
public:
   AuthorsAttribute( String^ name1, String^ name2 )
   {
      authorName1 = name1;
      authorName2 = name2;
   }

protected:
   String^ authorName1;
   String^ authorName2;

public:

   property String^ AuthorName1 
   {
      String^ get()
      {
         return authorName1;
      }

      void set( String^ value )
      {
         authorName1 = value;
      }
   }

   property String^ AuthorName2 
   {
      String^ get()
      {
         return authorName2;
      }

      void set( String^ value )
      {
         authorName2 = value;
      }
   }

   // Use the hash code of the string objects and xor them together. 
   virtual int GetHashCode() override
   {
      return authorName1->GetHashCode() ^ authorName2->GetHashCode();
   }

   // Determine if the object is a match to this one. 
   virtual bool Match( Object^ obj ) override
   {
      // Obviously a match. 
      if ( obj == this )
            return true;

      // Obviously we're not null, so no. 
      if ( obj == nullptr )
            return false;

      if ( dynamic_cast<AuthorsAttribute^>(obj) )

      // Combine the hash codes and see if they're unchanged. 
      return (dynamic_cast<AuthorsAttribute^>(obj)->GetHashCode() & GetHashCode()) == GetHashCode();
      else 
            return false;
   }
};


// Add some authors to methods of a class. 
public ref class TestClass1
{
public:

   [Authors("William Shakespeare","Herman Melville")]
   void Method1(){}


   [Authors("Leo Tolstoy","John Milton")]
   void Method2(){}

};


// Add authors to a second class's methods. 
public ref class TestClass2
{
public:

   [Authors("William Shakespeare","Herman Melville")]
   void Method1(){}


   [Authors("Leo Tolstoy","John Milton")]
   void Method2(){}


   [Authors("William Shakespeare","John Milton")]
   void Method3(){}

};

int main()
{
   // Get the type for both classes to access their metadata.
   Type^ clsType1 = TestClass1::typeid;
   Type^ clsType2 = TestClass2::typeid;

   // Iterate through each method of the first class.
   System::Collections::IEnumerator^ myEnum = clsType1->GetMethods()->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      MethodInfo^ mInfo1 = safe_cast<MethodInfo^>(myEnum->Current);

      // Check each method for the Authors attribute.
      AuthorsAttribute^ authAttr1 = dynamic_cast<AuthorsAttribute^>(Attribute::GetCustomAttribute( mInfo1, AuthorsAttribute::typeid ));
      if ( authAttr1 != nullptr )
      {
         // Display the authors.
         Console::WriteLine( "Method {0} was authored by {1} and {2}.", mInfo1->Name, authAttr1->AuthorName1, authAttr1->AuthorName2 );

         // Iterate through each method of the second class.
         System::Collections::IEnumerator^ myEnum1 = clsType2->GetMethods()->GetEnumerator();
         while ( myEnum1->MoveNext() )
         {
            MethodInfo^ mInfo2 = safe_cast<MethodInfo^>(myEnum1->Current);

            // Check each method for the Authors attribute.
            AuthorsAttribute^ authAttr2 = dynamic_cast<AuthorsAttribute^>(Attribute::GetCustomAttribute( mInfo2, AuthorsAttribute::typeid ));

            // Compare with the authors in the first class. 
            if ( authAttr2 != nullptr && authAttr2->Match(authAttr1) )
                        Console::WriteLine( "Method {0} in class {1} was authored by the same team.", mInfo2->Name, clsType2->Name );
         }
         Console::WriteLine();
      }
   }
}

/*
 * Output:
 * Method Method1 was authored by William Shakespeare and Herman Melville.
 * Method Method1 in class TestClass2 was authored by the same team.
 *
 * Method Method2 was authored by Leo Tolstoy and John Milton.
 * Method Method2 in class TestClass2 was authored by the same team.
 */