Type.MakeByRefType Method

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

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)

Syntax

Public Overridable Function MakeByRefType As Type
public 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).

Exceptions

Exception Condition
NotSupportedException

The invoked method is not supported in the base class.

TypeLoadException

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

Remarks

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&.

Version Notes

Windows Phone

MakeByRefType does not throw TypeLoadException when the MakeByRefType method for a byref type is called.

Examples

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

Imports System.Reflection

Public Class Example
   Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
      ' Create a Type object that represents a one-dimensional
      ' array of Example objects.
      Dim t As Type = GetType(Example).MakeArrayType()
      outputBlock.Text &= vbCrLf & "Array of Example: " & t.ToString() & vbCrLf

      ' Create a Type object that represents a two-dimensional
      ' array of Example objects.
      t = GetType(Example).MakeArrayType(2)
      outputBlock.Text &= vbCrLf & "Two-dimensional array of Example: " & t.ToString() & vbCrLf

      ' Demonstrate an exception when an invalid array rank is
      ' specified.
      Try
         t = GetType(Example).MakeArrayType(-1)
      Catch ex As Exception
         outputBlock.Text &= vbCrLf & ex.ToString() & vbCrLf
      End Try

      ' Create a Type object that represents a ByRef parameter
      ' of type Example.
      t = GetType(Example).MakeByRefType()
      outputBlock.Text &= vbCrLf & "ByRef Example: " & t.ToString() & vbCrLf

      ' 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.
      Dim t2 As Type = GetType(Example)
      Dim mi As MethodInfo = t2.GetMethod("Test")
      Dim pi As ParameterInfo = mi.GetParameters()(0)
      Dim pt As Type = pi.ParameterType
      outputBlock.Text &= "Are the ByRef types equal? " & (t Is pt) & vbCrLf

      ' Create a Type object that represents a pointer to an
      ' Example object.
      t = GetType(Example).MakePointerType()
      outputBlock.Text &= vbCrLf & "Pointer to Example: " & t.ToString() & vbCrLf
   End Sub

   ' A sample method with a ByRef parameter.
   '
   Public Sub Test(ByRef e As Example)
   End Sub
End Class

' This example produces output similar to the following:
'
'Array of Example: SilverlightApplication.Example[]
'
'Two-dimensional array of Example: SilverlightApplication.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 SilverlightApplication.Example.Demo(TextBlock outputBlock)
'
'ByRef Example: SilverlightApplication.Example&
'Are the ByRef types equal? True
'
'Pointer to Example: SilverlightApplication.Example*
using System;
using System.Reflection;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      // Create a Type object that represents a one-dimensional
      // array of Example objects.
      Type t = typeof(Example).MakeArrayType();
      outputBlock.Text += String.Format("\r\nArray of Example: {0}\n", t);

      // Create a Type object that represents a two-dimensional
      // array of Example objects.
      t = typeof(Example).MakeArrayType(2);
      outputBlock.Text += String.Format("\r\nTwo-dimensional array of Example: {0}\n", t);

      // Demonstrate an exception when an invalid array rank is
      // specified.
      try
      {
         t = typeof(Example).MakeArrayType(-1);
      }
      catch (Exception ex)
      {
         outputBlock.Text += String.Format("\r\n{0}\n", ex);
      }

      // Create a Type object that represents a ByRef parameter
      // of type Example.
      t = typeof(Example).MakeByRefType();
      outputBlock.Text += String.Format("\r\nByRef Example: {0}\n", 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 = typeof(Example);
      MethodInfo mi = t2.GetMethod("Test");
      ParameterInfo pi = mi.GetParameters()[0];
      Type pt = pi.ParameterType;
      outputBlock.Text += String.Format("Are the ByRef types equal? {0}\n", (t == pt));

      // Create a Type object that represents a pointer to an
      // Example object.
      t = typeof(Example).MakePointerType();
      outputBlock.Text += String.Format("\r\nPointer to Example: {0}\n", t);
   }

   // A sample method with a ByRef parameter.
   //
   public void Test(ref Example e)
   {
   }
}

/* 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.Demo(TextBlock outputBlock)

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

Pointer to Example: Example*

 */

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

See Also

Reference

Type Class

System Namespace

MakeArrayType

MakePointerType