C# と VB.NET の質問掲示板

VB.NETの質問です。
よろしくお願いします。

class1

Private Sub Display()
    
            Dim BindingSource1 As New BindingSource

            BindingSource1.DataSource = OracleOperat.GetIncetance.Display("SELECT * from D_SQLTEST1") ←←←ここでNULLエラーがでます。

            DataGridView1.DataSource = BindingSource1.DataSource
end Sub

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Display()
    End Sub



class2（OracleOperat）

Imports Oracle.ManagedDataAccess.Client
Imports Oracle.ManagedDataAccess.Types

 Private Shared incetance As OracleOperat
    '接続子
    Private Const pConnectionString As String = "接続省略"
    '接続用
    Protected Shared Property OraConnect As OracleConnection = Nothing

    ' 接続
    Public Shared Function GetIncetance() As OracleOperat

        If OraConnect IsNot Nothing Then

            OraConnect = New OracleConnection()
            OraConnect.Open()

        End If

        Return incetance
    End Function

    ''' <summary>
    ''' データベースを表示する
    ''' </summary>
    ''' <param name="SQL"></param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Function Display(ByVal SQL As String) As DataTable

        'コマンド設定
        Dim cmd As New OracleCommand
        cmd.CommandText = SQL
        cmd.Connection = OraConnect

        'アダプタ
        Dim oraAdapter As New OracleDataAdapter

        oraAdapter = New OracleDataAdapter(cmd.CommandText, pConnectionString)

        '読み込み
        Dim Table As New DataTable()
        oraAdapter.Fill(Table)

        Return Table

    End Function