byte[] bufPic;
string filePath = "";
Stream myStream;
MemoryStream picFile = new MemoryStream();
OpenFileDialog open = new OpenFileDialog();
open.Filter = "bmp files (*.bmp) | *.bmp";
open.RestoreDirectory = true;
if (open.ShowDialog() == DialogResult.OK)
{
	if ((myStream = login.OpenFile()) != null)
	{
		myStream.Close();
	}
}

filePath = open.FileName.ToString();
Image image = Image.FromFile(filePath);
image.Save(picFile, ImageFormat.Bmp);
bufPic = picFile.GetBuffer();

using (MemoryStream ms = new MemoryStream(myPic))
{
	Image image1 = Image.FromStream(ms);
	ms.Close();
	pic.Image = image1;
}

//其中mypic是byte类型，存放"二进制"的数组,pic是PictureBox控件

public void Save()
{
    using (System.IO.FileStream stream = new System.IO.FileStream())
    {
        byte[] buffer = new byte[stream.Length];
        stream.Read(buffer, 0, (int)stream.Length);
        stream.Close();
        string strName = System.IO.Path.GetFileNameWithoutExtension(file);
        SqlCommand cmd = new SqlCommand("Insert into Temp(name,photo) values(@name,@image)", sqlConn);
        cmd.Parameters.Add("@name", SqlDbType.VarChar).Value = strName;
        cmd.Parameters.Add("@image", SqlDbType.Image).Value = buffer;
        cmd.ExecuteNonQuery();
    }
}

public void GetImage()
{
    SqlCommand cmd = new SqlCommand(@"SELECT name, photo FROM Temp", sqlConn);
    sqlConn.Open();
    SqlDataReader reader = cmd.ExecuteReader();
    if (reader.Read())
    {
        image_filename = (string)reader.GetValue(0);
        byte[] image_bytes = (byte[])reader.GetValue(1);
        MemoryStream ms = new MemoryStream(image_bytes);
        Bitmap bmap = new Bitmap(ms);
        return bmap;

    }
}