ASP.NET中存取图片到数据库的示例

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        //开发环境:Window 2000、SQLServer2000、.Net Framework SDK正式版
        //开发语言:C#、ASP.Net
        //简介:数据库中图片存蓄及读取
        //作者:engine
        /*
        说明:在ASP中,我们用Request.TotalBytes、Request.BinaryRead()来上传图片,这个可恶的BinaryRead()方法非常笨,单个文件上传倒没什么大事,单如果多个图片上专可就花大气力了…!而现在ASP.Net中将会把解决以前ASP中文件上传的种种问题,使你在ASP.Net中轻轻松松开发出功能强大的上传程序,下面大家看看例子啦。
        */
        //注意:由于作者水平有限,错误是难免的,如发现错误请指教
        //Email:e_engine@21cn.com
        /*
        首先在SQL Server中建立一个图片存储的数库表,ImageData Column为图象二进制数据储存字段,ImageContentType Column为图象文件类型记录字段,ImageDescription Column为储蓄图象文件说明字段,ImageSize Column为储存图象文件长度字段,结构如下:
        CREATE TABLE [dbo].[ImageStore] (
        [ImageID] [int] IDENTITY (1, 1) NOT NULL ,
        [ImageData] [image] NULL ,
        [ImageContentType] [varchar] (50) COLLATE Chinese_PRC_CI_AS NULL ,
        [ImageDescription] [varchar] (200) COLLATE Chinese_PRC_CI_AS NULL ,
        [ImageSize] [int] NULL
        ) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
        */
        //UpLoadImage.aspx程序内容如下:
        <%@ Page Inherits="UploadImage.UploadImage" SRC="UpLoadImage.cs" Language="C#"%>
        <HTML><title>上传图片</title>
        <BODY bgcolor="#FFFFFF">
        <FORM ENCTYPE="multipart/form-data" RUNAT="server" ID="Form1">
        <TABLE RUNAT="server" WIDTH="700" ALIGN="left" ID="Table1" cellpadding="0" cellspacing="0" border="0">
        <TR>
        <TD>上传图片(选择你要上传的图片)</TD>
        <TD>
        <INPUT TYPE="file" ID="UP_FILE" RUNAT="server" STYLE="Width:320" ACCEPT="text/*" NAME="UP_FILE">
        </TD>
        </TR>
        <TR>
        <TD>
        文件说明(添加上传图片说明,如:作者、出处)
        </TD>
        <TD>
        <asp:TextBox RUNAT="server" WIDTH="239" ID="txtDescription" MAINTAINSTATE="false" />
        </TD>
        </TR>
        <TR>
        <TD>
        <asp:Label RUNAT="server" ID="txtMessage" FORECOLOR="red" MAINTAINSTATE="false" />
        </TD>
        <TD>
        <asp:Button RUNAT="server" WIDTH="239" ONCLICK="Button_Submit" TEXT="Upload Image" />
        </TD>
        </TR>
        </TABLE>
        </FORM>
        </BODY>
        </HTML>
        //-------------------------------------------------------------------
        //UpLoadImage.cs程序内容如下:
        using System;
        using System.Web;
        using System.IO;
        using System.Data;
        using System.Data.SqlClient;
        using System.Web.UI;
        using System.Web.UI.WebControls;
        using System.Web.UI.HtmlControls;
        namespace UploadImage
        {
        public class UploadImage : Page {
        protected HtmlInputFile UP_FILE; //HtmlControl、WebControls控件对象
        protected TextBox txtDescription;
        protected Label txtMessage;
        protected Int32 FileLength = 0; //记录文件长度变量
        protected void Button_Submit(System.Object sender, System.EventArgs e) {
        HttpPostedFile UpFile = UP_FILE.PostedFile; //HttpPostedFile对象,用于读取图象文件属性
        FileLength = UpFile.ContentLength; //记录文件长度
        try {
        if (FileLength == 0) { //文件长度为零时
        txtMessage.Text = "<b>请你选择你要上传的文件</b>";
        } else {
        Byte[] FileByteArray = new Byte[FileLength]; //图象文件临时储存Byte数组
        Stream StreamObject = UpFile.InputStream; //建立数据流对像
        //读取图象文件数据,FileByteArray为数据储存体,0为数据指针位置、FileLnegth为数据长度
        StreamObject.Read(FileByteArray,0,FileLength);
        //建立SQL Server链接
        SqlConnection Con = new SqlConnection("Data Source=Localhost;Initial Catalog=testdb;User ID=sa;Pwd=;");
        String SqlCmd = "INSERT INTO ImageStore (ImageData, ImageContentType, ImageDescription, ImageSize) VALUES (@Image, @ContentType, @ImageDescription, @ImageSize)";
        SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);
        CmdObj.Parameters.Add("@Image",SqlDbType.Binary, FileLength).Value = FileByteArray;
        CmdObj.Parameters.Add("@ContentType", SqlDbType.VarChar,50).Value = UpFile.ContentType; //记录文件类型
        //把其它单表数据记录上传
        CmdObj.Parameters.Add("@ImageDescription", SqlDbType.VarChar,200).Value = txtDescription.Text;
        //记录文件长度,读取时使用
        CmdObj.Parameters.Add("@ImageSize", SqlDbType.BigInt,8).Value = UpFile.ContentLength;
        Con.Open();
        CmdObj.ExecuteNonQuery();
        Con.Close();
        txtMessage.Text = "<p><b>OK!你已经成功上传你的图片</b>";//提示上传成功
        }
        } catch (Exception ex) {
        txtMessage.Text = ex.Message.ToString();
        }}}}
        //----------------------------------------------------------------------
        //好了,图片已经上传到数据库,现在还要干什么呢?当然是在数据库中读取及显示在Web页中啦,请看以下程序:
        //ReadImage.aspx程序内容如下:
        /-----------------------------------------------------------------------
        <%@ Page Inherits="ReadImage.MainDisplay" SRC="ReadImage.cs"%>
        //----------------------------------------------------------------------
        //ReadImage.cs程序内容如下:
        using System;
        using System.Data;
        using System.Data.SqlClient;
        using System.Web.UI;
        using System.Web.UI.WebControls;
        using System.Web.UI.HtmlControls;
        namespace ReadImage {
        public class MainDisplay : System.Web.UI.Page {
        public void Page_Load(System.Object sender, System.EventArgs e) {
        int ImgID = Convert.ToInt32(Request.QueryString["ImgID"]); //ImgID为图片ID
        //建立数据库链接
        SqlConnection Con = new SqlConnection("Data Source=KING;Initial Catalog=testdb;User ID=sa;Pwd=;");
        String SqlCmd = "SELECT * FROM ImageStore WHERE ImageID = @ImageID";
        SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);
        CmdObj.Parameters.Add("@ImageID", SqlDbType.Int).Value = ImgID;
        Con.Open();
        SqlDataReader SqlReader = CmdObj.ExecuteReader();
        SqlReader.Read();
        Response.ContentType = (string)SqlReader["ImageContentType"];//设定输出文件类型
        //输出图象文件二进制数制
        Response.OutputStream.Write((byte[])SqlReader["ImageData"], 0, (int)SqlReader["ImageSize"]);
        Response.End();
        Con.Close();
        //很简单吧^_^
        }
        }
        }
        //--------------------------------------------------------------------
        //最后,我们当然要把它在Web页面显示出来啦
        //ShowImage.hml
        <html>
        <body>
        这个是从数据库读取出来的图象:<img src="ReadImage.aspx?ImgID=1">
        <body>
        </html>
        //------------------------------------------------------------------
        //最后,这程序当然还很多改进之处,希望大家多想想多编编一定可以写出更多的图象上传程序
        //Good Luck,engine
        本文转自
http://blog.phoenixtv.com/html/93/203093-361208.html  
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