Question

In the following subroutine, will the StreamReader be closed properly when the exception is thrown? Or do I have do something myself to ensure this?

Sub mySub()
   Dim sr As StreamReader = File.OpenText("someFilename")
   Dim line As String = sr.ReadLine()
   While Not (line Is Nothing)
      ' Some logic here

      If someCondition Then
         Throw New Exception("someExplanation")
      End If

      line = sr.ReadLine()
   End While
End Sub

Answer 1

You should wrap the StreamReader variable in a using statement.

Using sr as StreamReader = File.OpenText("someFilename")
...
End Using