I generate qr code for name and country and member

qr code generated without any problem

but i need to use memory stream and not use save file dialog

my code as below

 using (SaveFileDialog sv = new SaveFileDialog() { Filter = "JPEG|.jpg", ValidateNames = true })
                    {
                        if (sv.ShowDialog() == DialogResult.OK)
                        {
                            MessagingToolkit.QRCode.Codec.QRCodeEncoder encoder = new MessagingToolkit.QRCode.Codec.QRCodeEncoder();
                            encoder.QRCodeScale = 8;

                            string encoding = "UserName : " + textBox4.Text + "\r\n" + "Country : " + comboBox3.Text + "\r\n" + "Membership :" + comboBox5.Text;

                            Bitmap bmp = encoder.Encode(encoding);
                            pictureBox1.Image = bmp;
                            path = sv.FileName;
                            bmp.Save(path, ImageFormat.Jpeg);
                        }

                    }

How to replace save file dialog by using memory stream ?