How to release memory after performing a certain task?

Question

In a certain task, I have to upload 6 photos in 6 PictureBox, for this I use the method below:

 private void simpleButton1_Click(object sender, EventArgs e) // botao carregar foto
    {
        OpenFileDialog carrega_foto = new OpenFileDialog();
        carrega_foto.Filter = "jpg|*.jpg";

        if (carrega_foto.ShowDialog() == DialogResult.OK)
        {
            if(pic1 == 0)
            {
                pictureBox1.ImageLocation = carrega_foto.FileName;

                pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;

                pic1 = 1;
            }
            else  if(pic2 == 0)
            {
                pictureBox2.ImageLocation = carrega_foto.FileName;

                pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;

                pic2 = 1;
            }
            else if (pic3 == 0)
            {
                pictureBox3.ImageLocation = carrega_foto.FileName;

                pictureBox3.SizeMode = PictureBoxSizeMode.StretchImage;

                pic3 = 1;
            }
            else if (pic4 == 0)
            {
                pictureBox4.ImageLocation = carrega_foto.FileName;

                pictureBox4.SizeMode = PictureBoxSizeMode.StretchImage;

                pic4 = 1;
            }
            else if (pic5 == 0)
            {
                pictureBox5.ImageLocation = carrega_foto.FileName;

                pictureBox5.SizeMode = PictureBoxSizeMode.StretchImage;

                pic5 = 1;
            }
            else if (pic6 == 0)
            {
                pictureBox6.ImageLocation = carrega_foto.FileName;

                pictureBox6.SizeMode = PictureBoxSizeMode.StretchImage;

                pic6 = 1;
            }
        }
    }

So I take the photos, resize them, transform them into one array of byte[] and saved in the database, with the method below:

            try
            {
                PictureBox[] List_Picture = { pictureBox1, pictureBox2, pictureBox3, pictureBox4, pictureBox5, pictureBox6 };

                foreach (PictureBox Pic in List_Picture)
                {
                    if (Pic.ImageLocation != null)
                    {
                        MemoryStream stream = new MemoryStream();

                        EncoderParameters myEncoderParameters = new EncoderParameters(1);

                        EncoderParameter myEncoderParameter = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, 10L);

                        myEncoderParameters.Param[0] = myEncoderParameter;

                        var codec = ObterCodec(Pic.Image.RawFormat);

                        Pic.Image.Save(stream, codec, myEncoderParameters);                            

                        byte[] Bfoto = stream.ToArray();

                        Classes.Cadastro.Crm.Analise_CRM Cad_Foto = new Classes.Cadastro.Crm.Analise_CRM();

                        Cad_Foto.Cad_Foto_Anal_Crm(textEdit8.Text, Bfoto);

                        Pic.Dispose();
                    }
                }
            }
            catch (Exception error)
            {
                MessageBox.Show("Erro, Contate o adiministrador!" + "\n" + error, "Salvar", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }     

then performing a debug I saw that when I upload the photos, is used enough memory for that, so far so good..

However, after I save the photo in the bank, how do I release this memory used?

tried to use the method Dispose but it didn’t work! What happens and that if I try to perform this task again, the exception below is generated:

Answer 1

Free the Garbage Collection:

GC.Collect();

more information:

https://msdn.microsoft.com/en-us/library/0xy59wtx(v=vs.110). aspx

Answer 2

I managed to solve the problem, with the following code:

if (pictureBox1.Image != null) 
{
   pictureBox1.Image.Dispose();
   pictureBox1.Image = null;
}

Refencia: How to set images at runtime (Windows Forms)