Type::MakeByRefType Method ()


Returns a Type object that represents the current type when passed as a ref parameter (ByRef parameter in Visual Basic).

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

virtual Type^ MakeByRefType()

Return Value

Type: System::Type^

A Type object that represents the current type when passed as a ref parameter (ByRef parameter in Visual Basic).

Exception Condition

The invoked method is not supported in the base class.


The current type is TypedReference.


The current type is a ByRef type. That is, Type::IsByRef returns true.

The MakeByRefType method provides a way to generate ref types (ByRef in Visual Basic) for parameter lists.

Using the syntax of Microsoft intermediate language (MSIL), if the current Type object represents Int32, this method returns a Type object representing Int32&.

The following code example creates array, ref (ByRef in Visual Basic), and pointer types for the Test class.

using namespace System;
using namespace System::Reflection;

public ref class Example
   static void Main()
      // Create a Type object that represents a one-dimensional
      // array of Example objects.
      Type^ t = Example::typeid->MakeArrayType();
      Console::WriteLine( L"\r\nArray of Example: {0}", t );

      // Create a Type object that represents a two-dimensional
      // array of Example objects.
      t = Example::typeid->MakeArrayType( 2 );
      Console::WriteLine( L"\r\nTwo-dimensional array of Example: {0}", t );

      // Demonstrate an exception when an invalid array rank is
      // specified.
         t = Example::typeid->MakeArrayType(  -1 );
      catch ( Exception^ ex ) 
         Console::WriteLine( L"\r\n{0}", ex );

      // Create a Type object that represents a ByRef parameter
      // of type Example.
      t = Example::typeid->MakeByRefType();
      Console::WriteLine( L"\r\nByRef Example: {0}", t );

      // Get a Type object representing the Example class, a
      // MethodInfo representing the "Test" method, a ParameterInfo
      // representing the parameter of type Example, and finally
      // a Type object representing the type of this ByRef parameter.
      // Compare this Type object with the Type object created using
      // MakeByRefType.
      Type^ t2 = Example::typeid;
      MethodInfo^ mi = t2->GetMethod( L"Test" );
      ParameterInfo^ pi = mi->GetParameters()[ 0 ];
      Type^ pt = pi->ParameterType;
      Console::WriteLine( L"Are the ByRef types equal? {0}", (t == pt) );

      // Create a Type object that represents a pointer to an
      // Example object.
      t = Example::typeid->MakePointerType();
      Console::WriteLine( L"\r\nPointer to Example: {0}", t );

   // A sample method with a ByRef parameter.
   void Test( interior_ptr<Example^> /*e*/ )

int main()

/* This example produces output similar to the following:

Array of Example: Example[]

Two-dimensional array of Example: Example[,]

System.IndexOutOfRangeException: Index was outside the bounds of the array.
   at System.RuntimeType.MakeArrayType(Int32 rank) in c:\vbl\ndp\clr\src\BCL\System\RtType.cs:line 2999
   at Example.Main()

ByRef Example: Example&
Are the ByRef types equal? True

Pointer to Example: Example*


Universal Windows Platform
Available since 8
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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