Method 1 for ASP.

Last Update:2014-09-11 Source: Internet

Author: User

Tags urlencode

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1. First create a new page page for download processing, such as download.aspx, with nothing in it.
2. Add a Downloadhandler class that inherits from the IHttpHandler interface and can be used to synchronize requests for HTTP processing from a defined HTTP handler.
public class Downloadhandler:ihttphandler
{
public void ProcessRequest (HttpContext context)
{
HttpResponse Response = context. Response;
HttpRequest Request = context. Request;
System.IO.Stream iStream = null;
byte[] buffer = new byte[10240];
int length;
Long dataToRead;
Try
{
string filename = Filehelper.decrypt (request["FN"]); Get the file name by decrypting
string filepath = HttpContext.Current.Server.MapPath ("~/") + "files/" + filename; File path to download
IStream = new System.IO.FileStream (filepath, System.IO.FileMode.Open,
System.IO.FileAccess.Read, System.IO.FileShare.Read);
Response.Clear ();
dataToRead = Istream.length;
Long p = 0;
if (request.headers["Range"]! = NULL)
{
Response.statuscode = 206;
p = long. Parse (request.headers["Range"). Replace ("bytes=", ""). Replace ("-", ""));
}
if (P! = 0)
{
Response.AddHeader ("Content-range", "bytes" + p.tostring () + "-" + ((long) (dataToRead-1)). ToString () + "/" + datatoread.tostring ());
}
Response.AddHeader ("Content-length", ((Long) (datatoread-p)). ToString ());
Response.ContentType = "Application/octet-stream";
Response.AddHeader ("Content-disposition", "attachment; Filename= "+ System.Web.HttpUtility.UrlEncode (System.Text.Encoding.GetEncoding (65001). GetBytes (path.getfilename (filename)));
Istream.position = p;
dataToRead = datatoread-p;
while (dataToRead > 0)
{
if (response.isclientconnected)
{
Length = istream.read (buffer, 0, 10240);
Response.OutputStream.Write (buffer, 0, length);
Response.Flush ();
Buffer = new byte[10240];
dataToRead = Datatoread-length;
}
Else
{
dataToRead =-1;
}
}
}
catch (Exception ex)
{
Response.Write ("Error:" + ex.) Message);
}
Finally
{
if (iStream! = null)
{
Istream.close ();
}
Response.End ();
}
}
public bool IsReusable
{
get {return true;}
}
}
3. Here is a file name plus decryption problem, is to prevent the file specific name exposure in the status bar, so add a Filehelper class, the code is as follows:
public class Filehelper
{
public static string Encrypt (string filename)
{
byte[] buffer = HttpContext.Current.Request.ContentEncoding.GetBytes (filename);
Return Httputility.urlencode (convert.tobase64string (buffer));
}
public static string Decrypt (String encryptfilename)
{
byte[] buffer = convert.frombase64string (encryptfilename);
return HttpContext.Current.Request.ContentEncoding.GetString (buffer);
}
}
The file name is added and decrypted with BASE64 code.
4. On the Web. config, add the httphandlers node as follows:
<system.web>
<add verb= "*" path= "download.aspx" type= "Downloadhandler"/>
</system.web>
5. Now create a new ASPX page to download the file:
The Default.aspx code is as follows:
Default.aspx Code
<%@ page language= "C #" autoeventwireup= "true" codefile= "Default.aspx.cs" inherits= "_default"%>
<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">
<title> File Download </title>
<body>
<form id= "Form1" runat= "Server" >
<div>
<asp:hyperlink id= "link" runat= "server" text= "File Download" ></asp:HyperLink>
</div>
</form>
</body>
The Default.aspx.cs code is as follows:
Default.aspx.cs Code
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;
public partial class _default:system.web.ui.page
{
protected void Page_Load (object sender, EventArgs e)
{
String url = Filehelper.encrypt ("Designpattern.chm");
Link. NAVIGATEURL = "~/download.aspx?fn=" + url;
}
}

Method 1 for ASP.

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

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