Comments on: Adding “Check for update” feature to your C# application

By: mech

mech — Fri, 18 Nov 2011 10:21:50 +0000

Matthew, I’m not sure if you are protecting the xml file containing the newest version information or the installer itself. Anyway, you should pass the credentials to the reader. In case of the xml file, here is the example: http://msdn.microsoft.com/en-us/library/47as68k4%28v=vs.71%29.aspx. And here is the basic authentication for the WebRequest (used to dowload the installer: http://www.ie-soft.de/blog/PermaLink,guid,11609e8d-e0fc-41f4-83a2-6e8ea46339f6.aspx). Those topic are not covered by this tutorial in order to keep it simple. Securing the installer or version info with basic auth isn’t a common thing. The downside is that you have to hardcode the credentials in your app. And when someone is using a proxy, he can intercept the request and response, so it’s not secure.

By: Matthew

Matthew — Thu, 10 Nov 2011 04:46:02 +0000

Mech,

First of all, thank you so much for the tutorial. It will make my apps much more manageable.

I have one question:
The place where I store my updated files is secured with an htaccess password. Is there a was to incorporate that securability in this tutorial?

By: Madhu Nair

Madhu Nair — Thu, 28 Oct 2010 10:49:21 +0000

Hi Mech,

Yours was an Excellent Article. Thank you so much.

By: mech

mech — Tue, 10 Aug 2010 08:31:47 +0000

Steve,
Your C# compiler seems to be more strict :) Please try initializing the variable before the try…finally block like this:
XmlTextReader reader = null;

By: Steve

Steve — Sat, 24 Jul 2010 14:49:55 +0000

I get a error here:

finally
{
if (reader != null) reader.Close();
}

It says “Error use of unsigned local variable “reader”

By: Jorge Sierra

Jorge Sierra — Mon, 26 Apr 2010 19:05:59 +0000

Well, I did some test and it works great.
Let me include it on my project.

By: miliu

miliu — Wed, 03 Mar 2010 15:10:53 +0000

Thanks for the nice article. I found it when I try to make VS publishing and CheckForUpdate work together. Do you have any thought on that?

By the way, on parsing out the version info from the xml file, it would be much easier using XPath. e.g.
XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(xmlUrl);
Version version = new Version(xmlDoc.SelectSingleNode(“/ourfancyapp/version”).InnerText);
string url = xmlDoc.SelectSingleNode(“/ourfancyapp/url”).InnerText;

By: Fullmetal

Fullmetal — Mon, 25 Jan 2010 19:15:49 +0000

I used this code along with a downloader request code, and now the application checks the XML, and if there is an update, will ask if its OK to download it. it will then download it and install the Update. I am planning on adding a “update from USB drive” option that will check the drive for the XML file, and if the version is a newer one, install the update package from the USB drive.

By: mech

mech — Tue, 19 Jan 2010 11:38:19 +0000

Hello,

@OverTech: Yes, indeed, HttpWebRequest gives you more tcp/ip control than XmlTextReader does. I’ve checked your code snippet and it seems fine to be, well done :)

@Ranhiru: You should host two files: the XML and your installer for the new version, so users can download it. Luckily there are some free web hosting services that allow you to do so.

By: Ranhiru

Ranhiru — Sat, 16 Jan 2010 14:15:10 +0000

This is really interesting!!! Just what i was looking for :D
I was really keen on using ClickOnce but this is much much more easy and neat! I just have to host the XML file somewhere :D

Thanx a lot :) :)