I just wasted another hour, trying to figure out, what exactly ASP.NET was trying to tell me, when giving me an "ASPNET: Make sure that the class defined in this code file matches the 'inherits' attribute, and that it extends the correct base class (e.g. Page or UserControl)." message on compiling my ascx file.

Ok, so I used a custom namespace, but I've done that hundreds of times, so that shouldn't be the problem. I also had a custom base class inheriting from UserControl. Also, nothing I haven't done before. So what was the issue now?!

I basically retyped everything concerning the namespace and class names in all files, but nothing helped. So I reverted to commenting out my code. This helped me find the issue: I used a

<% if (somethingOrOther) { %> Some code here <% } %>

construct in my ascx-file (Please don't start an argument on whether this is good practice or not. I know it's not the cleanest way to do things, but that is not the concern here :-) ), and actually forgot to put in the closing <% } %>. Ok, my fault, but shouldn't you get a better Compiler message than "ASPNET: Make sure that the class defined in this code file matches the 'inherits' attribute, and that it extends the correct base class (e.g. Page or UserControl)."?!

So, if you encouter this error (and believe me, I've had it more than once due to typos), and are 100% positive you've spelled everything correctly, check for unbalanced parentheses!

Yesterday, I had one of those WTF moments. I had a page with a form for entering two addresses. Both had the same fields, including a RadioButtonList with identical items. Since the items are resourced, I decided to optimize the performance by reusing the ListItems like so:

ListItem[] items = new ListItem[2];
items[0] = new ListItem(this.GetString("salutation.Mister"), "Mr");
items[1] = new ListItem(this.GetString("salutation.Misses"), "Mrs");
this.salutation.Items.AddRange(items);
this.salutation2.Items.AddRange(items);

Simple eh. Everything seems to be ok. And was I amazed, when I tested it, and I always got the SelectedItem to be the one selected in salutation2. I double-checked every location were I was storing the values, in case I forgot to change the field name after copy/pasting. But everything was correct, as far as I could tell. I even checked the values submitted by the browser, they were also correct.

Finally, it hit me: The ListItem has a Selected property, and it is used to find the RadioButtonLists SelectedItem property. And since I reused the items, the first list parses its items on postback, sets the appropriate ListItem's Selected property to true. Same thing happens with the second RadioButtonList. And since the ListItems are used in both lists, the last one wins.

So, I changed my code to look like this:

ListItem[] items = new ListItem[2];
items[0] = new ListItem(this.GetString("salutation.Mister"), "Mr");
items[1] = new ListItem(this.GetString("salutation.Misses"), "Mrs");
this.salutation.Items.AddRange(items);
items = new ListItem[2];
items[0] = new ListItem(this.GetString("salutation.Mister"), "Mr");
items[1] = new ListItem(this.GetString("salutation.Misses"), "Mrs");
this.salutation2.Items.AddRange(items);

Now everything works as it should. So next time, be careful when reusing your ListItems!

Today, I had to make a template for a mailing. I decided to create it as a stationery for Outlook, since this was the desired way of sending the mails. Not much to it, one might think. I created the HTML for the template (of course using the dreaded layout tables, since OL2007 went back to the stone age with its rendering engine), and copied it and the required images to the stationery folder. Having done that, the stationery showed in my list and I was able to create a mail using the template.

But what's this?! Were do the gaps in between the images come from?! And why are my shadows not aligned anymore?! Outlook simply went on and pratically destroyed my layout. I basically tried everything that came to my mind, trying to fix the gaps: modified paddings and margins using css, html attributes, added fixed widths and heights, nothing seemed to work. I even removed all the tables and simply placed two images after one another, no white space in between. Still, I got my gaps.

When everything seemed hopeless, I decided to simply send the mail the way it was. Guess what: everything is in perfect shape, when the mail arrives. No gaps, everything is aligned perfectly. I can even simply forward this mail, and it looks great in the editor. So the gaps only show, when you first create the mail using the stationery. Afterwards, everything is as it should be.

<rant>Now that's what I call a consistent user experience! Great job from the folks at Microsoft. I wasted a whole day trying to work around this bug.</rant>

And by the way, using stationery is probably not the best solution, since Outlook completely reformats your code and places all those unneccessary MSO* css styles in your mail's code. So if something goes wrong with your mail, you might consider NOT using Outlook to send it in the first place.