把图片存入数据库

图片存入数据库需要把图片转成二进制才能存入，怎么把图片转成二进制，这就是关键。

首先，在sql数据库建一个表image，只有一个字段im，数据类型image。

建好之后，打开visual studio，建一个windows窗体应用程序

下面是效果图：

代码：

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

namespace TestForm1
{
    public partial class FormImageInSql : Form
    {
        public FormImageInSql()
        {
            InitializeComponent();
        }

       /// <summary>
        /// 存入数据库
       /// </summary>
        private void btn_before_Click(object sender, EventArgs e)
        {
            string filePath = @"....Imagesqiaoba.jpg";//WinForm窗体项目起始在debug文件夹下，写路径的时候注意了
            FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read);
            byte[] buffer = new byte[fs.Length];
            fs.Read(buffer, 0, (int)fs.Length);
            SqlConnection con = DBHelper.getConnection();
            string cmd_str = "insert into Image values(@buffer)";
            SqlCommand cmd = new SqlCommand(cmd_str, con);
            SqlParameter para = new SqlParameter("@buffer", SqlDbType.Image);
            para.Value = buffer;
            cmd.Parameters.Add(para);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
            MessageBox.Show("存入成功！");
        }

        /// <summary>
        /// 从数据库中读出
        /// </summary>
        private void btn_after_Click(object sender, EventArgs e)
        {
            string con_str = "select top 1 im from Image ";
            SqlConnection con = DBHelper.getConnection();
            SqlCommand cmd = new SqlCommand(con_str, con); con.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            dr.Read();
            MemoryStream ms = new MemoryStream((byte[])dr["im"]);
            Image image = Image.FromStream(ms, true);
            dr.Close();
            con.Close();
            pb_after.SizeMode = PictureBoxSizeMode.StretchImage;
            pb_after.Image = image; 
        }
    }
}