ASP.NET 上传图片至数据库并读取图片显示--二进制流方式

来源：互联网发布：向ncbi上传转录组数据编辑：程序博客网时间：2024/04/28 07:50

以二进制流的方式存入数据库，并读取显示

数据库的字段同样简单：
Image_ID int identity(1,1) primarykey not null
Image_Content image null
Image_Content以二进制形式保存图片

整体看一下例子里的页面组成：
上传图片页面和第一种方法一样，同样是用到FileUpload，以及一个Button，具体代码如下：

protectedvoid Button1_Click(object sender, EventArgs e)

{

       string name= FileUpload1.PostedFile.FileName;

       string type= name.Substring(name.LastIndexOf(".")+ 1);

        FileStream fs = File.OpenRead(name);

       byte[] content= newbyte[fs.Length];

        fs.Read(content, 0, content.Length);

        fs.Close();

        SqlConnection conn =new SqlConnection("Data Source=;Initial Catalog=;Persist Security Info=True;User ID=;Pooling=False;Password=");

        SqlCommand cmd = conn.CreateCommand();

        conn.Open();

        cmd.CommandText ="insert into Images(Image_Content) values (@content)";

        cmd.CommandType = CommandType.Text;

       if (type== "jpg"|| type == "gif"|| type == "bmp"|| type == "png")

        {

          SqlParameter para = cmd.Parameters.Add("@content", SqlDbType.Image);

          para.Value = content;

          cmd.ExecuteNonQuery();

        }

}

显示一张图片和显示一组图片有所不同，将会分别说明之。

显示一张图片，要用到Default.aspx和Default2.aspx。Default.aspx中有一个控件Image，它的属性ImageUrl指向Default2.aspx用于显示图片。Default2.aspx用于
读取图片。
Default.aspx.cs

protectedvoid Page_Load(object sender, EventArgs e)

{

        Image1.ImageUrl ="Default2.aspx";

}

Default2.aspx.cs

string imgid = Request.QueryString["imgid"];

        SqlConnection conn1 =new SqlConnection("Data Source=;Initial Catalog=;Persist Security Info=True;User ID=sa;Pooling=False;Password=");

        SqlCommand cmd1 =new SqlCommand("select Image_Content from Images where Image_ID=3", conn1);     //固定显示Image_ID为3的图片

        conn1.Open();

        SqlDataReader sdr = cmd1.ExecuteReader();

       if (sdr.Read())

        {

          Response.BinaryWrite((byte[])sdr["Image_Content"]);

        }

        Response.End();

显示一组图片时，用ashx Handle存放图片。同时用GridView以列显示图片。Image控件绑定Image_ID。
allimage.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="allimage.aspx.cs" Inherits="allimage"%>

<!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>BindImg</title>

</HEAD>

<body>

<form id="Form1" method="post" runat="server">

<FONT face="宋体">

<asp:DataGrid id="MyDataGrid" runat="server" AutoGenerateColumns="False" Width="632px">

<AlternatingItemStyle BackColor="Beige"></AlternatingItemStyle>

<HeaderStyle HorizontalAlign="Center"></HeaderStyle>

<Columns>

<asp:TemplateColumn HeaderText="Photo">

<ItemTemplate><asp:Image ID="Image1" runat="server" Height="70px" ImageUrl='<%# "Getimg.ashx?id="+Eval("Image_ID") %>'

Width="100px"/>

</ItemTemplate>

</asp:TemplateColumn>

</Columns>

</asp:DataGrid></FONT>

<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:PracticeConnectionString %>"

SelectCommand="SELECT * FROM [Images]"></asp:SqlDataSource>

</form>

</body>

</HTML>

allimage.aspx.cs

protectedvoid Page_Load(object sender, EventArgs e)

{

        MyDataGrid.DataSource = SqlDataSource1;

        MyDataGrid.DataBind();

}
Getimg.ashx
<%@ WebHandler Language="C#" Class="Getimg"%>
using System;

using System.Web;

using System.Data;

using System.Data.SqlClient;

using System.Configuration;

public class Getimg : IHttpHandler {

public void ProcessRequest (HttpContext context)

{

       int id= int.Parse(context.Request.QueryString["id"]);

        SqlConnection conn =new SqlConnection(@"server=;database=;uid=;pwd=");

        SqlCommand cmd =new SqlCommand("select Image_Content from Images where Image_ID='"+ id + "'", conn);

        cmd.Parameters.Add("@id", SqlDbType.Int).Value= id;

        conn.Open();

        SqlDataReader dr = cmd.ExecuteReader();

       if (dr.Read())

        {

          context.Response.BinaryWrite((byte[])dr["Image_Content"]);

        }

        dr.Close();

}

public bool IsReusable {

       get {

         returnfalse;

        }

}

}

转载 http://blog.163.com/sdq_1314/blog/static/166908254201081704330711/