DataGridViewのセルの値を行単位でチェックする方法

DataGridViewのセルの値を行単位でチェックする方法
VB.NET

Private Sub dgv1_RowValidating(ByVal sender As Object, _
    ByVal e As DataGridViewCellCancelEventArgs) _
    Handles dgv1.RowValidating

    Dim dgv As DataGridView = DirectCast(sender, DataGridView)
    If e.RowIndex = dgv.NewRowIndex OrElse Not dgv.IsCurrentRowDirty Then
        Exit Sub
    End If

    For Each cell As DataGridViewCell In dgv.Rows(e.RowIndex).Cells
        If cell.Value Is Nothing OrElse cell.Value.ToString() = "" Then
            dgv.Rows(e.RowIndex).ErrorText = _
                "セルに値を入力してください"
            e.Cancel = True
        End If
    Next
End Sub

Private Sub dgv1_RowValidated(ByVal sender As Object, _
    ByVal e As DataGridViewCellEventArgs) _
    Handles dgv1.RowValidated

    Dim dgv As DataGridView = DirectCast(sender, DataGridView)
    dgv.Rows(e.RowIndex).ErrorText = Nothing
End Sub

C#

private void dgv1_RowValidating(object sender,
    DataGridViewCellCancelEventArgs e)
{
    DataGridView dgv = (DataGridView)sender;

    if (e.RowIndex == dgv.NewRowIndex || !dgv.IsCurrentRowDirty)
    {
        return;
    }

    foreach (DataGridViewCell cell in dgv.Rows[e.RowIndex].Cells)
    {
        if (cell.Value == null || cell.Value.ToString() == "")
        {
            dgv.Rows[e.RowIndex].ErrorText =
                "セルに値を入力してください";
            e.Cancel = true;
        }
    }
}

private void dgv1_RowValidated(object sender,
    DataGridViewCellEventArgs e)
{
    DataGridView dgv = (DataGridView)sender;
    dgv.Rows[e.RowIndex].ErrorText = null;
}