Ajax 加載數據庫中的圖片

1，ashx頁面

<%@ WebHandler Language="C#" Class="GetImage" %>

using System;
using System.Web;
using System.Data;
using System.IO;

public class GetImage : IHttpHandler
{

    public void ProcessRequest(HttpContext context)
    {
        SQLHelper sqlH = new SQLHelper();
        string strID = context.Request["ID"];
        byte[] MyData = new byte[0];
        string str = "  select [ImageData] from [Leave] where [ID]='" + strID + "' ";
        DataTable dt = sqlH.ExecuteQuery(str, CommandType.Text);
        if (dt.Rows.Count > 0)
        {
            MyData = (byte[])dt.Rows[0][0];
            int ArraySize = MyData.GetUpperBound(0);

            context.Response.OutputStream.Write(MyData, 0, ArraySize);
        }
    }
    public bool IsReusable
    {
        get
        {
            return false;
        }
    }

}

2，aspx頁面：

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

<!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 type="text/javascript">

        function LoadImage(ElementID, id) {
            //ElementID <img>的ID
            var xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");  //WebClient
            if (!xmlhttp) {
                alert("創建xmlhttp對象異常");
                return false;
            }
            var url = "GetImage.ashx?ID=" + id + "&ts" + new Date();
            xmlhttp.open("POST", "GetImage.ashx?ID=" + id + "&ts" + new Date(), false);
            xmlhttp.onreadystatechange = function event() {
                if (xmlhttp.readystate == 4) {
                    if (xmlhttp.status == 200) {
                        document.getElementById(ElementID).src = url;
                    }
                    else {
                        alert("Ajax返回Error");
                    }
                }
            }
            xmlhttp.send();
        }

    </script>
</head>
<body>
    <form id="form1" runat="server">
        <div>
            <img id="Image" alt="" src="" />
            <input id="Text1" type="text" />
            <input id="Button1" type="button" value="button" onclick="LoadImage('Image', '004')" />
        </div>
    </form>
</body>
</html>

 

posted @ 2013-02-11 06:32  sirili  阅读(238)  评论(0)  编辑  收藏  举报