保存/读取图片到数据库

 private void SaveImage(string fileName)
        {
            // Read the file into a byte array
            using (FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read))
            {
                byte[] imageData = new Byte[fs.Length];
                fs.Read(imageData, 0, (int)fs.Length);

                using (SqlConnection conn = new SqlConnection(connectionString))
                {
                    string sql = "insert into image (imagefilename,blobdata) values (@filename,@blobdata)";
                    SqlCommand cmd = new SqlCommand(sql, conn);
                    cmd.Parameters.Add("@filename",SqlDbType.Text);
                    cmd.Parameters["@filename"].Direction = ParameterDirection.Input;
                    cmd.Parameters.Add("@blobdata", SqlDbType.Image);
                    cmd.Parameters["@blobdata"].Direction = ParameterDirection.Input;
                    // Store the byte array within the image field
                    cmd.Parameters["@filename"].Value = fileName;
                    cmd.Parameters["@blobdata"].Value = imageData;
                    conn.Open();
                    if (cmd.ExecuteNonQuery() == 1)
                    {
                        MessageBox.Show("Done");
                    }
                }
            }
        }

        private void LoadImage(string fileName)
        {
            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                string sql = "select blobdata from Image where ImageFileName like @filename";
                SqlCommand cmd = new SqlCommand(sql, conn);
                cmd.Parameters.Add("@filename", SqlDbType.Text);
                cmd.Parameters["@filename"].Value = fileName;

                conn.Open();

                object objImage = cmd.ExecuteScalar();

                byte[] buffer = (byte[])objImage;

                BinaryWriter bw = new BinaryWriter(new FileStream("C:\\abcd.png", FileMode.Create));
                bw.Write(buffer);
                bw.Close();

              MemoryStream ms = new MemoryStream(buffer);
                Image bgImage = Image.FromStream(ms);
                ms.Close();
                this.BackgroundImage = bgImage;
            }
            
        }