BC32126: 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

• Nullable<T>
• AddressOf Operator
• Nullable Value Types
• Generic Types in Visual Basic