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

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  

See Also

Nullable Value Types
IsNot Operator