图片保存到数据库的小程序

应一位网友要求，做了一个将图片保存到数据库和从数据库读取图片的小程序。

源码如下：

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

namespace ImageToDB
{
    public partial class UserEdit : Form
    {
        public UserEdit()
        {
            InitializeComponent();
        }
        private void UserEdit_Load(object sender, EventArgs e)
        {
            LoadNextUser();
        }
        string strConn = "Data Source=wangyang\\SQLEXPRESS;Initial Catalog=test;Persist Security Info=True;User ID=uap;Password=uap";
        string strGetTopOne = "select top 1 * from users ";

        /// <summary>
        /// 保存按钮事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            if (txtUserID.Text == "" || txtUserID.Text == string.Empty)
            {
                //新增
                if (txtUserName.Text == "" || txtImagePath.Text == "")
                {
                    MessageBox.Show("用户名和图片不能为空！");
                    return;
                }
                //这里看如何将图片保存到数据库的。
                FileStream fs = File.OpenRead(txtImagePath.Text);
                byte[] imageb = new byte[fs.Length];
                fs.Read(imageb, 0, imageb.Length);
                fs.Close();
                string strSQL = "insert into Users(UserName,UserImage)values(@UserName,@UserImage)";
                SqlConnection con = new SqlConnection(strConn);
                SqlCommand com3 = new SqlCommand(strSQL, con);
                com3.Parameters.Add("@UserName", SqlDbType.VarChar).Value = txtUserName.Text;
                com3.Parameters.Add("@UserImage", SqlDbType.Image).Value = imageb;
                if (com3.Connection.State == ConnectionState.Closed)
                    com3.Connection.Open();
                try
                {
                    com3.ExecuteNonQuery();
                    MessageBox.Show("新增用户成功！");
                }
                catch
                {
                    MessageBox.Show("新增用户失败！");
                }
                finally
                { com3.Connection.Close(); }

            }
            else
            {
                //修改
                //这里看如何将图片保存到数据库的。
                string strSQL = "update users set username=@UserName";
                if (txtImagePath.Text != "")
                    strSQL += ",userimage=@UserImage";
                SqlConnection con = new SqlConnection(strConn);
                SqlCommand com3 = new SqlCommand(strSQL, con);
                com3.Parameters.Add("@UserName", SqlDbType.VarChar).Value = txtUserName.Text;
                if (txtImagePath.Text != "")
                {
                    FileStream fs = File.OpenRead(txtImagePath.Text);
                    byte[] imageb = new byte[fs.Length];
                    fs.Read(imageb, 0, imageb.Length);
                    fs.Close();
                    com3.Parameters.Add("@UserImage", SqlDbType.Image).Value = imageb;
                }
                if (com3.Connection.State == ConnectionState.Closed)
                    com3.Connection.Open();
                try
                {
                    com3.ExecuteNonQuery();
                    MessageBox.Show("修改用户成功！");
                }
                catch
                {
                    MessageBox.Show("修改用户失败！"); 
                }
                finally
                { com3.Connection.Close(); }
            }

        }

        /// <summary>
        /// 下一位。
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button4_Click(object sender, EventArgs e)
        {
            string preUserID = txtUserID.Text;
            LoadNextUser();
            if (txtUserID.Text == preUserID)
                MessageBox.Show("已经是最后一位用户！");
        }

        /// <summary>
        /// 清空。
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            txtUserID.Text = "";
            txtUserName.Text = "";
            txtImagePath.Text = "";
            pictureBox1.Image = null;
        }
        /// <summary>
        /// 选择图片。
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btOpenImage_Click(object sender, EventArgs e)
        {
            openFileDialog1.Filter = "JPEG|*.jpg|GIF|*.gif";
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                txtImagePath.Text = openFileDialog1.FileName;
                FileStream fs = File.OpenRead(txtImagePath.Text);
                byte[] imageb = new byte[fs.Length];
                fs.Read(imageb, 0, imageb.Length);
                fs.Close();
                MemoryStream memStream = new MemoryStream(imageb);
                try
                {
                    Bitmap myimge = new Bitmap(memStream);
                    this.pictureBox1.Image = myimge;
                }
                catch
                {
                }
            }
        }

        /// <summary>
        /// 从数据库中读取下一位用户的信息。如果参数为空则读取第一条信息。
        /// </summary>
        /// <param name="PreUserID"></param>
        /// <returns></returns>
        public DataTable GetTopOneUser(string filter)
        {
            strGetTopOne = "select top 1 * from users ";
            if (filter != "" && filter != string.Empty)
                strGetTopOne += filter;
            SqlConnection con = new SqlConnection(strConn);
            SqlCommand com = new SqlCommand(strGetTopOne, con);
            if (con.State == ConnectionState.Closed)
                con.Open();
            SqlDataAdapter da = new SqlDataAdapter(com);
            DataSet ds = new DataSet();
            da.Fill(ds, "UserTable");
            if (ds != null && ds.Tables.Count > 0)
                return ds.Tables[0];
            else
                return null;
        }
        /// <summary>
        /// 加载下一位用户信息
        /// </summary>
        public void LoadNextUser()
        {
            //这里看如何将数据库图片读出来
            string filter ="";
            if (txtUserID.Text != "")
                filter = " where userid>" + txtUserID.Text;
            DataTable dt = GetTopOneUser(filter);
            if (dt.Rows.Count == 0)
                return;
            DataRow dr = dt.Rows[0];
            txtUserID.Text = dr["UserID"].ToString();
            txtUserName.Text = dr["UserName"].ToString();
            byte[] imageb = (byte[])dr["UserImage"];
            MemoryStream memStream = new MemoryStream(imageb);
            try
            {
                Bitmap myimge = new Bitmap(memStream);
                this.pictureBox1.Image = myimge;
            }
            catch
            {
            }
        }
        /// <summary>
        /// 加载上一位用户信息
        /// </summary>
        public void LoadPreUser()
        {
            string filter = "";
            if (txtUserID.Text != "")
                filter = " where userid<" + txtUserID.Text+" order by Userid desc";
            DataTable dt = GetTopOneUser(filter);
            if (dt.Rows.Count == 0)
                return;
            DataRow dr = dt.Rows[0];
            txtUserID.Text = dr["UserID"].ToString();
            txtUserName.Text = dr["UserName"].ToString();
            byte[] imageb = (byte[])dr["UserImage"];
            MemoryStream memStream = new MemoryStream(imageb);
            try
            {
                Bitmap myimge = new Bitmap(memStream);
                this.pictureBox1.Image = myimge;
            }
            catch
            {
            }
        }
        /// <summary>
        /// 关闭。
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button3_Click(object sender, EventArgs e)
        {
            this.Close();
        }
        /// <summary>
        /// 上一位
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button5_Click(object sender, EventArgs e)
        {
            string preUserID = txtUserID.Text;
            LoadPreUser();
            if (txtUserID.Text == preUserID)
                MessageBox.Show("已经是最前一位用户！");
            
        }
        /// <summary>
        /// 帮助。
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void linkLabel1_LinkClicked(object sender, LinkLabelLinkClickedEventArgs e)
        {
            help helper = new help();
            helper.Show();
        }
        
    }
}

界面如下：


说明：
不用担心数据库能不能存放下你保存的图片，数据库可以存放2GB大的图片，可以远远满足你的要求。

源码下载： CODE   演示版：DEMO