'IsNot' operand of type 'typename' can only be compared to 'Nothing', because 'typename' is a nullable type


Updated: July 20, 2015

For the latest documentation on Visual Studio 2017, see Visual Studio 2017 Documentation.

A variable declared as nullable has been compared to an expression other than Nothing using the IsNot operator.

Error ID: BC32128

To correct this error

  1. To compare a nullable type to an expression other than Nothing by using the IsNot operator, call the GetType method on the nullable type and compare the result to the expression, as shown in the following example.

    Dim number? As Integer = 5  
    If number IsNot Nothing Then  
      If number.GetType() IsNot Type.GetType("System.Int32") Then   
      End If  
    End If  

Nullable Value Types
IsNot Operator