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();        }       /// 
        /// 存入数据库       /// 
        private void btn_before_Click(object sender, EventArgs e)        {            string filePath = @"..\..\Images\qiaoba.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！");        }        /// 
        /// 从数据库中读出        /// 
        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;         }    }}