Why can't connect to Postgresql in Win 10 64bit when build release?

Question

The code of TDBACore.vb:

Imports System.ComponentModel
Imports System.Data

<EditorBrowsable(EditorBrowsableState.Never)> _
Public MustInherit Class TDBACore        
    Private Shared FRefCount As Integer

    Friend Shared FIsBeginTran As Boolean = False

    Friend Shared FConnection As IDbConnection

    Friend Shared FTransaction As IDbTransaction

    Private disposedValue As Boolean

    Friend Shared iRecheckTimeout As Integer
    Friend Shared iConnectionTimeOut As Integer

    Friend MustOverride Function CreateConnection() As IDbConnection

    Public Sub New()
        Me.disposedValue = False
        If TDBACore.FRefCount = 0 Then
            TDBACore.FConnection = Me.CreateConnection()
        End If
        TDBACore.FRefCount += 1

    End Sub

   Friend Shared Sub OpenConnection(ByVal ConnectionString As String)
    If TDBACore.FConnection.State = ConnectionState.Closed Then
        TDBACore.FConnection.ConnectionString = ConnectionString
        TDBACore.FConnection.Open()
    End If
   End Sub
End Class

The code of TDBOpener.vb:

Public NotInheritable Class TDBOpener
    Inherits TDBACore
    Public Shared ReadOnly _TDBOpener As New TDBOpener()
    Friend Overrides Function CreateConnection() As IDbConnection
        Return New NpgsqlConnection()
    End Function

    Public Shared Sub SetTimeoutValue(ByVal param_iRecheckTimeout As Integer, ByVal param_iConnectionTimeOut As Integer)
        TDBACore.iConnectionTimeOut = param_iConnectionTimeOut
        TDBACore.iRecheckTimeout = param_iRecheckTimeout
    End Sub

    Public Shared Sub Open(ByVal ConnectionString As String)
        TDBACore.OpenConnection(ConnectionString)
    End Sub
 End Class

I test connect to postgresql by Npgsql.dll 3.2.2.0:

TDBOpener.Open("Server=192.168.1.10;Port=5434;UserId=postgres;Password=123456;Database=testdb;CommandTimeout=300;")

I using Win 10, 64bit, vs 2017 .Net Framework 4.6

If i run by mode [Debug]: it can run function New() of TDBACore and connect ok. But if i run by mode [Release], it not go to function New() of TDBACore. Why? thanks all.(Notes: I try on win 7, it is ok.)

Answer 1

Win 10, 64bit, vs 2017 .Net Framework 4.6: If i run by mode [Release], it can't init Public Shared ReadOnly _TDBOpener As New TDBOpener()

My solution edit function Open of TDBOpener:

Public Shared Sub Open(ByVal ConnectionString As String)
        If TDBACore.FConnection Is Nothing Then
            Dim obOpen = _TDBOpener
        End If
        TDBACore.OpenConnection(ConnectionString)
End Sub

Answer 2

The reason you were having the problem, and the reason that the fix works, is because the compiler was optimizing out _TDBOpener since it wasn't being referenced. This question has more details.