图片保存到数据库和从数据库读取图片并显示（C＃）

图片保存到数据库的方法：

        public void imgToDB(string sql)

        {   //参数sql中要求保存的imge变量名称为@images

            //调用方法如：imgToDB("update UserPhoto set Photo=@images where UserNo='" + temp + "'");

            FileStream fs = File.OpenRead(t_photo.Text);

            byte[] imageb = new byte[fs.Length];

            fs.Read(imageb, 0, imageb.Length);

            fs.Close();

            SqlCommand com3 = new SqlCommand (sql,con);

            com3.Parameters.Add("@images", SqlDbType.Image).Value = imageb;

            if (com3.Connection.State == ConnectionState.Closed)

                com3.Connection.Open();

            try

            {

                com3.ExecuteNonQuery();

            }

            catch

            { }

            finally

            { com3.Connection.Close(); }

        }

数据库中读出图片并显示在picturebox中：

方法一：

private void ShowImage(string sql)

     {

     //调用方法如：ShowImage("select Photo from UserPhoto where UserNo='" + userno +"'");

     SqlCommand cmd = new SqlCommand(sql, conn);

     conn.Open();

     byte[] b= (byte[])cmd.ExecuteScalar();

     if (b.Length 〉 0)

     {

     MemoryStream stream = new MemoryStream(b, true);

     stream.Write(b, 0, b.Length);

     pictureBox1.Image = new Bitmap(stream);

     stream.Close();

     }

     conn.Close();

     }

方法二：当在dg中选中某行时：

  private void dg_MouseUp(object sender, MouseEventArgs e)

        {

            //整行选择

            if (e.Button == System.Windows.Forms.MouseButtons.Left)

            {//用户编号，姓名，性别，身份证号，籍贯，学院，系所，校区，部门，电话，照片

                 //显示相片

                object imgobj=dg[10, dg.CurrentRow.Index].Value;

                if (imgobj != null && !Convert.IsDBNull(imgobj))

                {

                    byte[] imgb = (byte[])imgobj;

                    MemoryStream memStream = new MemoryStream(imgb);

                    try

                    {

                        Bitmap myimge = new Bitmap(memStream);

                        this.pictureBox1.Image = myimge;

                    }

                    catch

                    {

                        DB.msgbox("从数据库读取相片失败！");

                    }

                }

                else

                    pictureBox1.Image = null;

            }

        }