Eliminer valeurs deja selectionnées lignes precedentes combobox dans Datagridview

Public Sub verifier_article()
        cn.Open()
        Dim liste() As String
        ReDim liste(ind)
        For i = 0 To ind
            liste(i) = DataGridView1(1, i).Value
        Next
        Dim cmd As New SqlCommand
        Dim dr As SqlDataReader
        cmd.Connection = cn
        cmd.CommandText = "select designationArticle from Article where designationArticle not IN ('" & String.Join("','", liste) & "')"
        Dim Dgvc As New DataGridViewComboBoxCell
        dr = cmd.ExecuteReader
        If dr.HasRows Then
            While dr.Read
                Dgvc.Items.Add(dr(0))
            End While
            DataGridView1.Item(1, ind) = Dgvc
        End If
        dr.Close()
        cn.Close()
    End Sub

 Private Sub DataGridView1_UserAddedRow(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewRowEventArgs)
        ind = ind + 1
        verifier_article()
    End Sub

 Public Sub charger_article()
        Dim listFirst As List(Of String) = New List(Of String)
        Dim listSecond As List(Of String) = New List(Of String)
        cn.Open()
        Dim cmd As New SqlCommand
        Dim dr As SqlDataReader
        cmd.Connection = cn
        cmd.CommandText = "select designationArticle from Article"
        Dim Dgvc As New DataGridViewComboBoxCell
        dr = cmd.ExecuteReader
        If dr.HasRows Then
            While dr.Read
                listFirst.Add(dr(0))
                ' Dgvc.Items.Add(dr(0))
            End While
        End If
        For i = 0 To DataGridView1.Rows.Count - 2
            listSecond.Add(DataGridView1(1, i).Value)
        Next
        Dim different As IEnumerable(Of String) = listFirst.Except(listSecond)
        Dgvc.Items.Add(different.ToList)
        DataGridView1.Item(1, ind) = Dgvc
        dr.Close()
        cn.Close()
    End Sub

 cn.Open()
        Dim liste() As String
         ReDim liste(DataGridView1.Rows.Count)
        For i = 0 To DataGridView1.Rows.Count - 3
            liste(i) = (DataGridView1(1, i).Value)
            MsgBox(liste(i))
        Next
        Dim cmd As New SqlCommand
        Dim dr As SqlDataReader
        cmd.Connection = cn
        cmd.CommandText = "select designationArticle from Article where designationArticle not IN ('" & String.Join("','", liste) & "')"
        Dim Dgvc As New DataGridViewComboBoxCell
        dr = cmd.ExecuteReader
        If dr.HasRows Then
            While dr.Read
                'listSecond.Add(dr(0))
                Dgvc.Items.Add(dr(0))
            End While
            DataGridView1.Item(1, ind) = Dgvc
        End If
        dr.Close()
        cn.Close()