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I recently come across an interesting request which read like this: A simple webapplication with one Textbox and one label. The Textbox has Autopostback=”true” and has an event listener attached to the TextChanged event. In the TextChanged event the label’s text is set to the text in the textbox. A javascript...

I just realized I have not posted anything here over the last couple of months which is definitely not a good thing to keep a blog alive… It’s been a busy period, I’ve been working on the Italian Developer Support Blog with my colleague Raffaele , of course working with our customers on Support Cases...

Consider this scenario: you are browsing a web site which at some point switches from http to https, and your browser show you a warning. In Firefox you get: Connection Partially Encrypted Parts of the page you are viewing were not encrypted before being transmitted over the Internet. Information sent...

I got a couple of cases of this kind recently, one where the web pages were served by PerformancePoint and the other one was a completely custom web site, but both of them shared the same common root issue: browsing some specific pages, the CPU on client got constantly at 100% and the GUI was completely...

The TreeView control has built-in Ajax capabilities when it comes to dynamically fill it nodes; this is done through the PopulateNodesFromClient : Sometimes, it is not practical to statically predefine the tree structure due to data size or custom content that depends on user input. Because of this,...

The question arose from a customer whom had implemented an application to stream PDF files from ASP.NET and was also using HTTP compression to save bandwidth and improve download time; using IE 6, Adobe Reader failed to open the file with the following error message: Adobe Reader could not open ‘<name>...

Imagine you are debugging your dump, are already looking forward for the output of the command you just typed (say a kpn to get the stack of a thread) and you get this message instead: *** ERROR: Symbol file could not be found.  Defaulted to export symbols for mscorwks.dll WARNING: Frame IP not...

I recently got this question from a customer whom is binding some data to a DropDownList control inside a GridView; the various items inside the DropDownList has variable length while the control itself per their page resign requirements must be fixed, making it difficult to fully read and understand...

This is what we got couple of weeks ago: an Ajax enabled ASP.NET web application was using a TreeView control within an UpdatePanel to show a complex tree of hierarchical data (the sample we got had more than 2.000 nodes with varying degrees of nesting). The result was that browsing the tree within IE...

Again on the Ajax-compression subject (see here and here ), here's another error I got recently: Sys.WebForms.PageRequestManagerParserErrorException: The message received from the server could not be parsed. Common causes for this error are when the response is modified by calls to Response.Write...

A few days before Christmas I had a case where the customer was intermittently getting troubles with his javascript/Ajax resource; as usual everything was working fine on the development machine, but when moved on the production server the application started throwing some client side javascript exceptions...

I stumbled across this issue multiple times during my life of web developer (which begun about 10 years ago), it appeared every now and then to complicate things when I was in the middle of a heavy debugging sessions and doing frequent changes to my pages; I was expecting some kind of results but despite...

I got a couple of cases about this problem recently... Imagine this scenario: you install the .NET Framework 3.0 on your client, and then browse an ASP.NET based web site; you get a 406 HTTP return code from the web server, which means "Client browser does not accept the MIME type of the requested page...

Here's an interesting story about performance I had the chance to work on over the last couple of weeks. The object of the call was a UserControl embedded in Internet Explorer, which was very slow to load the first time you browsed the page, but then was performing quite well after that long delay (around...

The customer was working on a WinXP machine joined to a domain, but had logged in using a local account (I've not tested if this may have contributed to the problem so this may be a useless information). Anyway to make things easy I connected to the faulting machine using EasyAssist to have a better...

Wow, this has been a tough one I closed this afternoon. The customer has developed a custom IE toolbar to interact with their portal, and found that when running this on Vista, IE displayed a warning dialog asking the user's consent to run an external program; in particular that was happening when the...

Create a very simple page in ASP.NET 2.0, add a TreeView control and set ShowLines=true ; now browse the page with Internet Explorer 7: you'll very likely see something like this:   In IE 6 this looks good... The point is that Internet Explorer 7 changes the boxing model: now a box that's too small...

Every now and then we get calls from a customer who decided to migrate his application from ASP.NET 1.1 to 2.0 (and sometimes those are mission-critical ones...) just changing the relevant mappings in IIS console, to then discover that the application is no longer working, or has some quite weird behavior...

My colleague Stefano had this case a few weeks ago, but since he has not a blog (yet ) and I've been partially involved in it, I thought this might be interesting to share... So, here is the story: the customer wanted to disable a button inside the onBlur event of a textbox through client-side Javascript...

  This is an easy one, but we got cases like this every now and then... maybe worth repeating. If you use Windows Integrated Authentication in IIS, everything works fine if you browse "http://netbiosname", but Integrated Authentication fails is you browse "http://dnsname". Why...

While working to customize a bit my blog (and you can easily see I'm not a graphic designer! ) I struggled trying to understand and sort out the tangle of CSS styles I can override to change how these pages look (at this is still "work in progress"). Luckily in our internal blogger discussion list...

PROBLEM You have a Windows Forms component hosted in Internet Explorer, and you want to catch events raised by this control from client side scripting; to avoid security errors at runtime, the control must have "Allow calls to unmanaged assemblies" permission. if you do this, you'll notice that this...