如何将数据库二进制图片保存到硬盘上

1.建立一个aspx页面，copy html代码
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
      <title>Untitled Page</title>
</head>
<body>
      <form id="form1" runat="server">
      <div>
           <asp:FileUpload ID="FileUpload1" runat="server" /> <asp:TextBox ID="txtUserName"
              runat="server"></asp:TextBox>
          <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="保存" />
          <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="将数据库二进制图片存到磁盘" Width="207px" /></div>
      </form>
</body>
</html>

2.cs代码
using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.IO;
public partial class Default3 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

      }
      protected void Button2_Click(object sender, EventArgs e)
      {
          //把图片保存成数据库二进制形式
          Stream ImageStream;
          string Path = FileUpload1.PostedFile.FileName;// 文件名称
          int Size = FileUpload1.PostedFile.ContentLength; // 文件大小
          string Type = FileUpload1.PostedFile.ContentType; // 文件类型
          ImageStream = FileUpload1.PostedFile.InputStream;
          byte[] Content = new byte[Size];
          int Status = ImageStream.Read(Content, 0, Size);

SqlConnection conn = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
SqlCommand comm = new SqlCommand("insert into testimage (UserName,Image,Path,Type) values(@UserName,@Image,@Path,@Type)", conn);

          comm.CommandType = CommandType.Text;
          comm.Parameters.Add("@UserName", SqlDbType.VarChar, 255).Value = txtUserName.Text;
          comm.Parameters.Add("@Image", SqlDbType.Image).Value = Content;
          comm.Parameters.Add("@Path", SqlDbType.VarChar, 255).Value = Path;
          comm.Parameters.Add("@Type", SqlDbType.VarChar, 255).Value = Type;

          conn.Open();
          comm.ExecuteNonQuery();
          conn.Close();
      }
      protected void Button1_Click(object sender, EventArgs e)
      {
          //把数据库二进制图片转存到硬盘中
          string connStr = ConfigurationSettings.AppSettings["ConnectionString"];
          SqlConnection conn = new SqlConnection(connStr);
          string sql = "select * from testimage";
          SqlCommand cmd = new SqlCommand(sql, conn);
          conn.Open();
          SqlDataReader dr = cmd.ExecuteReader();
          while (dr.Read())
          {
              byte[] bytes = (byte[])dr["Image"];
              FileStream fs = new FileStream(@"c:\" + dr["UserID"] + ".jpg", FileMode.Create, FileAccess.Write);
              fs.Write(bytes, 0, bytes.Length);
              fs.Flush();
              fs.Close();
          }
          dr.Close();
          conn.Close();
      }
}

3.数据库脚本
if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[TestImage]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [dbo].[TestImage]
GO

CREATE TABLE [dbo].[TestImage] (
      [UserID] [int] IDENTITY (1, 1) NOT NULL ,
      [UserName] [nvarchar] (500) COLLATE Chinese_PRC_CI_AS NULL ,
      [Image] [image] NULL ,
      [Path] [nvarchar] (500) COLLATE Chinese_PRC_CI_AS NULL ,
      [Type] [nvarchar] (20) COLLATE SQL_Latin1_General_CP1_CI_AS NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO