February 2011 Entries

It’s ok to throw System.Exception…

No. No it’s not. It’s not just me saying that, it’s the Microsoft guidelines: http://msdn.microsoft.com/e... Do not throw System.Exception or System.SystemException. Also – as important: Do not catch System.Exception or System.SystemException in framework code, unless you intend to re-throw.. Throwing: Always, always try to pick the most specific exception type you can, if the parameter you have received in your method is null, throw an ArgumentNullException, value received ......

Silverlight ProgressBar issues with Binding

The ProgressBar pretty much does what it says on the tin, displays progress, in a bar form (well, by default anyhow). It’s pretty simple to use: <ProgressBar Minimum="0" Maximum="100" Value="50"/> Gives you a progress bar with 50% of it filled: Easy! But of course, we’re wanting to use binding to change the value, again, pretty easy, have a ViewModel with a ‘Value’ in it, and bind: <ProgressBar Minimum="0" Maximum="100" Value="{Binding Value}"/> Spiffy, and whilst we’re at it, why not ......

Unknown C# keywords: params

Often overlooked, and (some may say) unloved, is the params keyword, but it’s an awesome keyword, and one you should definitely check out. What does it do? Well, it lets you specify a single parameter that can have a variable number of arguments. You what? Best shown with an example, let’s say we write an add method: public int Add(int first, int second) { return first + second; } meh, it’s alright, does what it says on the tin, but it’s not exactly awe-inspiring… Oh noes! You need to add 3 things ......