數據庫存儲圖片

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Data.SqlClient;

namespace WindowsFormsApplication1
{
    public partial class cun_img : Form
    {
        public cun_img()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)//-----------------------打開
        {
            DialogResult dr = openFileDialog1.ShowDialog();
            if (dr==DialogResult.OK)
            {
                FileStream fs = new FileStream(openFileDialog1.FileName, FileMode.Open, FileAccess.Read);//打開讀取文件 讀到fs這個流裏面
                Image img = System.Drawing.Bitmap.FromStream(fs);//fs從硬盤上讀取的圖片經過drawing.bitmap位圖繪製出來就是image類
                pictureBox1.Image = img;//指定
            }
        }

        private void button2_Click(object sender, EventArgs e)//---------------存入到數據庫
        {
            DialogResult dr = openFileDialog1.ShowDialog();
            if (dr==DialogResult.OK)
            {
                //文件流
                FileStream fs = new FileStream(openFileDialog1.FileName, FileMode.Open, FileAccess.Read);
                BinaryReader br = new BinaryReader(fs);//二進制讀取器
                byte[] buffer = br.ReadBytes(int.Parse(fs.Length.ToString()));

                //鏈接數據庫
                SqlConnection conn = new SqlConnection("server=.;database=tupian;user=sa;pwd=123");
                SqlCommand cmd = conn.CreateCommand();
                cmd.CommandText = "insert into imatable values(@buffer)";
                cmd.Parameters.Add("@buffer", buffer);
                conn.Open();
                cmd.ExecuteNonQuery();
                cmd.Dispose();
                conn.Close();
            }
        }

        private void button3_Click(object sender, EventArgs e)//-----------------------從數據庫讀取
        {
            SqlConnection conn = new SqlConnection("server=.;database=tupian;user=sa;pwd=123");
            SqlCommand cmd = conn.CreateCommand();
            cmd.CommandText = "select *from imatable";
            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            byte[] buffer = null;
            if (dr.Read())
            {
                buffer = (byte[])dr["img"];//轉換爲byte數組型
            }
            cmd.Dispose();
            conn.Close();
            //將二進制數據buffer顯示爲圖片
            MemoryStream ms = new MemoryStream(buffer);//構建對象
            Image img = System.Drawing.Image.FromStream(ms);
            pictureBox1.Image = img;
        }
    }
}