ASP.NET中存取图片到数据库的示例(C#)

ASP.NET中存取图片到数据库的示例(C#)
//开发环境:Window 2003、SQLServer2000、.Net 2.0
//开发语言:C#、ASP.Net
//简介:图片预览,数据库中图片存储及读取
//作者:wayne-ivan
//Email:wayne-ivan@163.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]
*/


//PreviewAndSave.aspx 页面如下
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="PreviewAndSave.aspx.cs" Inherits="_PreviewAndSave" %>
<!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>无标题页</title>
<script language="javascript" type="text/javascript">
    function preview()
    {
        var x = document.getElementById("file4");
        //var y = document.getElementById("Image1");
        var z = document.getElementById("Image2");
        if(!x || !x.value || !z)
            return;
         var patn = /\.jpg$|\.jpeg$|\.gif$/i;
         if(patn.test(x.value))
         {  
            //y.src = "file://localhost/" + x.value;
            z.src = "file://localhost/" + x.value;
         }
         else
         {  
                alert("您选择的似乎不是图像文件。");
          }
    }
</script>
</head>
<body id="UP_FILEa">
    <form id="form1" runat="server">
    <div>
        &nbsp;<asp:Image ID="Image1" runat="server" Height="174px" Width="159px" />
        <input id="UP_FILE" runat="server" type="file" onpropertychange="document.all.Image1.src='file:///'+this.value"/>
        <br />
        <asp:Image ID="Image2" runat="server" Height="174px" Width="159px" />
        <input type="file" name="file4" id="file4" onchange="preview()" /> <br />
        <asp:TextBox ID="txtDescription" runat="server" Visible="False"></asp:TextBox>&nbsp;
        <asp:Label ID="txtMessage" runat="server" Text="Label" Visible="False"></asp:Label>&nbsp;
        <asp:Button ID="BtnSave" runat="server" OnClick="Button1_Click" Text="上传" />
        &nbsp;
        <asp:Button ID="BtnRead" runat="server" OnClick="Button3_Click" Text="读取" />&nbsp;
        <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="读取到另一个页面" Visible="False" /> <br/>
        <asp:RadioButtonList ID="RadioButtonList1" runat="server" AutoPostBack="True" OnSelectedIndexChanged="RadioButtonList1_SelectedIndexChanged">
        </asp:RadioButtonList></div>
    </form>
</body>
</html>





//PreviewAndSave.aspx.cs 如下
using System;
using System.Data;
using System.Configuration;
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 _PreviewAndSave : System.Web.UI.Page
{
    protected Int32 FileLength = 0;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            bindRadioList();

        }
    }
    private void bindRadioList()
    {
        DataTable dt = new DataTable();
        string strCon = System.Configuration.ConfigurationSettings.AppSettings["DSN"];
        SqlConnection Con = new SqlConnection(strCon);
        Con.Open();
        SqlDataAdapter da = new SqlDataAdapter("select ImageID from ImageStore", Con);
        da.Fill(dt);
        RadioButtonList1.DataTextField = "ImageID";
        RadioButtonList1.DataValueField = "ImageID";
        RadioButtonList1.DataSource = dt;
        RadioButtonList1.DataBind();
        if (dt.Rows.Count > 0)
            RadioButtonList1.SelectedIndex = 0;

    }
    //保存图片到数据库
    protected void Button1_Click(object sender, 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=ghrmsdb;User ID=sa;Pwd=sa;");
                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();
        }
        //Response.Redirect("ReadImage.aspx?id=1");
        bindRadioList();
    }
    
    protected void Button3_Click(object sender, EventArgs e)
    {
        //int ImgID = Convert.ToInt32(Request.QueryString["ID"]); //ID为图片ID
        int ImgID = Convert.ToInt32(RadioButtonList1.SelectedValue);
        //建立数据库链接
        string strCon = System.Configuration.ConfigurationSettings.AppSettings["DSN"];
        SqlConnection Con = new SqlConnection(strCon);

        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
        string fileName = Server.MapPath(this.Request.ApplicationPath) + "\\" + ImgID + ".jpg";// + "\\1.jpg";
        System.IO.File.WriteAllBytes(fileName, (byte[])SqlReader["ImageData"]);
        this.Image1.ImageUrl = this.Request.ApplicationPath + "/" + ImgID + ".jpg";
        
        //输出图象文件二进制数制
        //Response.OutputStream.Write((byte[])SqlReader["ImageData"], 0, (int)SqlReader["ImageSize"]);
        //Response.End();
        //也可以保存为图像
        //      FileStream fs = new FileStream(@"C:\aa.BMP", FileMode.OpenOrCreate, FileAccess.Write);
        //      fs.Write((byte[])SqlReader["ImageData"], 0,(int)SqlReader["ImageSize"]);
        //      fs.Close();

        Con.Close();
    }
    protected void RadioButtonList1_SelectedIndexChanged(object sender, EventArgs e)
    {
        ReadPicutre();
    }

    //从数据库中读取文件显示出来
    private void ReadPicutre()
    {
        int ImgID = Convert.ToInt32(RadioButtonList1.SelectedValue);
        //建立数据库链接
        string strCon = System.Configuration.ConfigurationSettings.AppSettings["DSN"];
        SqlConnection Con = new SqlConnection(strCon);

        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

        //将文件保存到文件夹,然后在读取
        string fileName = Server.MapPath(this.Request.ApplicationPath) + "\\" + ImgID + ".jpg";// + "\\1.jpg";
        System.IO.File.WriteAllBytes(fileName, (byte[])SqlReader["ImageData"]);
        this.Image1.ImageUrl = this.Request.ApplicationPath + "/" + ImgID + ".jpg";

        //输出图象文件二进制数制
        //Response.OutputStream.Write((byte[])SqlReader["ImageData"], 0, (int)SqlReader["ImageSize"]);
        //Response.End();
        //也可以保存为图像
        //      FileStream fs = new FileStream(@"C:\aa.BMP", FileMode.OpenOrCreate, FileAccess.Write);
        //      fs.Write((byte[])SqlReader["ImageData"], 0,(int)SqlReader["ImageSize"]);
        //      fs.Close();

        Con.Close();
    }
    //在新打开的页面显示图片
    protected void Button2_Click(object sender, EventArgs e)
    {
        //得到用户要上传的文件名
        string strFilePathName = UP_FILE.PostedFile.FileName;
        string strFileName = Path.GetFileName(strFilePathName);
        int FileLength = UP_FILE.PostedFile.ContentLength;
        if (FileLength <= 0)
            return;
        try
        {//上传文件
            Byte[] FileByteArray = new Byte[FileLength]; //图象文件临时储存Byte数组
            Stream StreamObject = UP_FILE.PostedFile.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
            string strCon = System.Configuration.ConfigurationSettings.AppSettings["DSN"];
            SqlConnection Con = new SqlConnection(strCon);
            // String SqlCmd = "Insert INTO ImageStore (ImageData, ImageContentType, ImageDescription, ImageSize) VALUES (@Image, @ContentType, @ImageDescription, @ImageSize)";
            String SqlCmd = "Insert INTO ImageStore (ImageData) VALUES (@Image)";
            SqlCommand CmdObj = new SqlCommand(SqlCmd, Con);
            CmdObj.Parameters.Add("@Image", SqlDbType.Binary, FileLength).Value = FileByteArray;
            CmdObj.Parameters.Add("@ContentType", SqlDbType.VarChar, 50).Value = UP_FILE.PostedFile.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 = FileLength;
            Con.Open();
            CmdObj.ExecuteNonQuery();
            Con.Close();
            //跳转页面
            Response.Redirect("ReadImage.aspx?id=1");
        }
        catch
        {
        }
    }
}

原文地址:https://www.cnblogs.com/sontin/p/1929792.html