Methods of 'System.Nullable(Of T)' cannot be used as operands of the 'AddressOf' operator

A statement uses the AddressOf operator with an operand that represents a procedure of the Nullable<T> structure.

Error ID: BC32126

To correct this error

• Replace the procedure name in the AddressOf clause with an operand that is not a member of Nullable<T>.

• Write a class that wraps the method of Nullable<T> that you want to use. In the following example, the NullableWrapper class defines a new method named GetValueOrDefault. Because this new method is not a member of Nullable<T>, it can be applied to nullInstance, an instance of a nullable type, to form an argument for AddressOf.

  Module Module1
  
      Delegate Function Deleg() As Integer
  
      Sub Main()
          Dim nullInstance As New Nullable(Of Integer)(1)
  
          Dim del As Deleg
  
          ' GetValueOrDefault is a method of the Nullable generic
          ' type. It cannot be used as an operand of AddressOf.
          ' del = AddressOf nullInstance.GetValueOrDefault
  
          ' The following line uses the GetValueOrDefault method
          ' defined in the NullableWrapper class.
          del = AddressOf (New NullableWrapper(Of _
              Integer)(nullInstance)).GetValueOrDefault
  
          Console.WriteLine(del.Invoke())
      End Sub
  
      Class NullableWrapper(Of T As Structure)
          Private m_Value As Nullable(Of T)
  
          Sub New(ByVal Value As Nullable(Of T))
              m_Value = Value
          End Sub
  
          Public Function GetValueOrDefault() As T
              Return m_Value.Value
          End Function
      End Class
  End Module
  

See Also

Concepts

Nullable Value Types

Generic Types in Visual Basic

Reference

AddressOf Operator

Nullable<T>