implemented a generic handler in my application which works great for images, but when I manually type the handler URL in the browser with the image's querystring it prompts download instead of displaying. Here is my code:
public void ProcessRequest(HttpContext context)
{
if (this.FileName != null)
{
[code]...
For our application we provide users with file downloads that utilize handlers to serve the files. Currently, the way it is served to the user is through window.location. When using this, at times, it causes issues under IE8. When an error occurs, it cannot be caught under the page that called it.
A) Is there a way to serve an ashx file handler to the user where the page that called it can catch any exceptions made from thje handler
B) What is the correct way to serve the handler, eg. window.open, window.location, etc. Would return false at the end of the javascript solve this? Are there any other ways
In a basic scenario where I have a GridView with files to download and link buttons to download them, is there any benefit at all for creating a custom http handler for streaming those files as opposed to simply streaming from the event handler of the download link button?
Edit: As some suggested code reuse would favor the handler, however it's not an issue in this particular case. The handler is also faster being that it avoids the page life cycle, however this slight performance improvement is probably not worth creating a handler for in my particular situation. The only thing that comes to mind now is (assuming using the same aspx page approach) whether there is any special consideration in a situation where the GridView is inside an UpdatePanel?
I have a simple 'file download' generic handler which sets the response contenttype and headers before sending the file through the same response.
I also have Response.Cache.SetCacheability(HttpCacheability.server) set in the global.asax.
As I have noticed from various sources, Internet Explorer doesn't like this no-cache setting and gives an error when trying to download the file (requested site unavailable or cannot be found).
I thought maybe I could override this setting in the .ashx page, so I alter the response's cacheability setting to public. This did not solve the issue. removing the line from global.asax does solve the problem but obviously affects the whole site.
Is there a way of setting the cachability just for my generic handler?
We have a whole bunch of WML pages that are served out using ASHX files and we've had no problems with them. However, someone has just got a Windows 7 Phone and when they browse to one of these pages they get:
Can't download file! Windows Phone doesn't support .ashx files Is there some IIS configuration that we need to do to make this work?
Whats the best method to prompt a user to download something? In the past I've used window.open('file.pdf'); but I can see popup blockers having a problem with this. Of course I'll include a manual link aswel.I basically want something like the Microsoft Download page. So whats the script that prompts this?
View 3 RepliesI want to download any type of file on button click,so have created a .ashx page and redirected the .aspx page to the .ashx page.Is this way correct to do the task.Below mentioned code works fine.
<%@ WebHandler Language="C#" Class="Handler" %>
using System;
using System.Web;
public class Handler : IHttpHandler {
public void ProcessRequest (HttpContext context) {
var fileName = "Tracing.pdf";
[Code] ....
I've got a simple ASHX handler that returns an dynamically generated image; the image is generated from a custom created class, and an object belonging to this class is passed to the handler using Session (I'd rather avoid using QueryString).The handler is used as the URL of an image on a ASP form which is very simple: a drop down list, a button and an image. Basically, depending on what the user selects from the list, the appropriate image will be generated once the button is pressed.
At the start the actual image has it's Visible property set to false; I don't want the handler to display anything before the data is all there.Once the button is pressed, the required Session parameter is added containing the necessary object, and the page is refreshed using Server.Transfer. When the Page_load method detects that the Session parameter has been correctly set, it sets the Visible parameter on the image to true.After that the handler fires up and generates the image.
So far so good... However, if the user now picks something different from the list and presses the button, despite the correct object being passed in the Session, the image won't be updated. In fact, the handler won't even fire up (if I put a breakpoint in there). I need to close the browser window and reopen it for it to work.Any ideas what could be the cause of such behaviour?I suspect the answer is very simple, and I just don't know something fundamental about ASP (or handlers)...
What is the purpose of Handler (.ashx files) and what is the use ?
can i get any sample ?
I am running a website using IIS6 and i wrote a simple generic handler which return smaller images when it receive image url as query string. My problem is that the server is applying gzip to some file types such as .aspx and .ashx. And that made my response image from the handler appear with lower quality because they are compressed.
How can i disable gzip for just this handler file, i hope for a solution without editing the IIS.
How can i send data to an asp.net ashx handler? for instance if i want to send some xml to asp.net hanlder how is that possible?
View 2 RepliesI've created code to retrieve an image from the file system using an ASHX handler. The code displays the image correctly in Chrome, but I get a broken image in IE:
[Code]....
I have a webpage where I am displaying some data.
On the top of that I have a button. On click of this button I am calling my webhandler using jquery/json, passing in some data to this handler. Now this data can containg html tags. So whenever I try to click that button it gives that Potential threat script
error. So I thought let me include ValidateRequest = false to my webpage.
Now when i do this it never hits my handler. I tried to debug also but my breakpoint is never hit in my handler. How to handle this.
This is how I call my handler:
[Code]....
where hidden value is the value which I want to pass to my handler and may contain html tags..
Is it possible to call a handler using javascript code? e.g. i have a handler deployed at this location http://mysitename.com/getMyData.ashx. Can I call this handler or just request it using javascript?
View 3 RepliesI would like to open some page from external web-application in iframe. Usualy, I would indicate URL for iframe like this: URL = [URL] BUT. I need to send not only 'ID=12' parameter. I need to send a lot of data to handler in order to be processed. Usualy I do it by following code:
Dim wrq As WebRequest = WebRequest.Create(Data_WS_URL) wrq.Method = "POST" Dim postData As String = "PubmedIDs=" & vInput wrq.ContentType = "Application/x-www-form-urlencoded" Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
But when you use this code - you recieve response from webrequest as some amount of data - text or binary. I may write this respone to the place on the page where I wanted to have iframe. But response cannot always be accaptable. (for example - I render asp:Treeview by ASHX handler - when I do to ashx page - it renders well, collapse-expand works fine; but if I write web-response of ashx page as text/html - then there's something wrong with javascript, tags ids and collapsing nodes). And webresponse cannot be represented as as URL. How to combine this two approaches
1) Clear URL which can be set as source for iframe
2) Extra data for web-request, larger then QueryString can handle
I have a gridview and in it is code to display an image
[Code]....
This works fine for pass one variable. but I need to send two variables 'ImageNum' and 'refID' to the Handler.ashx page, any ideas how, tried a few things in last few hours and as yet no joy!
Is it possible to add a messagebox to an ASHX Handler? I used a handler to pass data from a Web Service to an internal system and need a messagebox to pop up to ask the user to choose from one option or another.
View 2 RepliesIs it possible to determine the HTTP protocol version (e.g. 1.0 vs. 1.1) used for a request within a .ashx handler? I can see all of the header information except for the version in Request.Params.
If not, what avenues are available to discover the HTTP protocol version when processing an HTTP request in ASP.Net?
I have created .ashx which implemented IRequiresSessionState, so I can create session variables in that ashx, it worked in IE, but doesn't work in Firefox.When access this session variable from other pages it's NULL.
View 1 RepliesWe are providing downloads of our application setups through an ASHX handler in ASP.NET.
A customer told us he uses some third party download manager application and that our way of providing the files currently does not support the "resume" feature of his download manager application.
My questions are:
What are the basic behind resuming a download? Is there a certain HTTP GET request that tells me the offset to start at?
Just looking for a bit of advice really my colleage suggested using a http handler .ashx file to handle the ajax calls that I will be getting on a web app via a jquery plug in on the page.What i have previously done is write a page _ControlName.aspx which looks at the url an takes or supplies what it needs in json format.What is the better way to handle ajax?
View 2 RepliesI've created a Web application (VS2008) that contains a single Generic Handler (handlername.ashx) and a web.config. I've also added a Web Setup project to use for deployment that uses the primary output from the Handler project. Install works without any errors and all the referenced DLLs are installed in the target location, with one issue. It doesn't install the ASHX file or the web.config.
Publishing the web app to the target location works as expected (includes both DLLs and the ASHX/Config files).
Is there something specific I need to do for the Web setup to include the ASHX/Config files?
Apologies for posting the ten billionth jQuery autocomplete question...I'm having trouble with a jQuery UI autocomplete textbox.I'm unsure if I'm doing the right thing client-side to re-populate the autocomplete data source following keystrokes.The javascript in my aspx page is as follows:
$(function() {
$("#<%=txtAuthorityName.ClientID%>").autocomplete({
minLength: 2,
[code]...
I got a $(document).ready() handler in my aspx page that fires twice. I trapped it to the follwing line of html (this line is part of the itemtemplate of a listview):
<img src='Images.ashx?Url=<%# Eval("Url")%>&Type=3' alt=''></img>
Seems that using the images.ashx is causing my problem, putting a 'normal' url as src gives me no problems.
It must be because the handler is called, but why is loading an image giving a second fire on $(document).ready()
It is only in IE8. Chrome, FF and safari work as expected.
We are using Google Analytics for our site, but since it uses client script in HTML output we are unable to track hits to any of our ASP.NET ASHX handler pages.
View 2 Replies