Question

I’m trying to convert some VB.net code into C# and having issues trying to convert this one line.

VB.NET

Dim myreg As Microsoft.Win32.Registry

I know it’s a static so I can’t create an instance but when I tried a VB.NET converter to C# the website gives me this:

Microsoft.Win32.Registry myreg = null;

And gives me an error message: ‘Microsoft.Win32.Registry’ is a ‘type’ but is used like a ‘variable’

In the last part of the Function in VB.NET, myreg is used:

Finally
  myreg = Nothing
End Try

Here’s the whole function:

Imports System.Data.OleDb
Imports System.Data
Imports Microsoft.Win32.RegistryKey
Imports MyLogger 'custom reference, not worried about this.

Private Function getRegistryString(ByVal sVal As String, Optional ByVal sKey As String = "") As String
    Dim myreg As Microsoft.Win32.Registry
    Dim s As String
    Try
        s = myreg.LocalMachine.OpenSubKey(sKey).GetValue(sVal)
    Catch ex As Exception
        l.EventLog(ex.Message, EventLogEntryType.Error)
        Throw ex
    Finally
        myreg = Nothing
    End Try
    Return s
    s = Nothing
End Function

Answer 1

In VB.NET, there is no way to define a shared (static) class. In C#, however, you can specify that a class is static. When a class is static, it forces all its members to be static as well. The compiler will give you an error if you try to declare a variable of a static type.

In VB, however, since there is no such thing as a shared class, it always allows you to declare a variable of any type, even though it’s entirely pointless because the instance will have no members.

Instead of declaring a variable as type Registry, you need to change the code to simply use the Registry class name, itself. Setting the variable to Nothing is meaningless because the variable never stores a reference to an object. It’s always Nothing.

Your function should read like this:

Private Function getRegistryString(ByVal sVal As String, Optional ByVal sKey As String = "") As String
    Dim s As String
    Try
        s = Microsoft.Win32.Registry.LocalMachine.OpenSubKey(sKey).GetValue(sVal)
    Catch ex As Exception
        l.EventLog(ex.Message, EventLogEntryType.Error)
        Throw ex
    End Try
    Return s
End Function