Posts

Testing a website with a root path

This post is really a reminder to myself, so that I can find the information quickly for the next time I reformat my hard drive! To run a website with a root path in Visual Studio 2005 follow these steps: Tools->External tools menu Click Add Title = Webserver Command = C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\WebDev.WebServer.EXE Arguments = /port:8080 /path:$(ProjectDir) Tick "Use output window" Whenever you need the webserver running just open your project and go to Tools->Webserver.

Calling base constructors in C#

I occasionally find it annoying that I cannot specify at which point in a class's constructor I wish to invoke the base constructor. Having C# always invoke it before any of the code in my descendant constructor is executed sometimes causes me problems. Considering .NET is capable of calling the ancestor constructor at any point I wondered why C# wont allow it. I contacted Anders Hejlsberg and he was kind enough to reply, unfortunately he seems to have answered a question I didn't ask :-) Anyway, I have been deleting some old emails today and I came across his response, which he gave me permission to publish: The problem with Delphi's model (allowing constructors to be called on an already constructed object) is that it makes it impossible to have provably immutable objects. Immutability is an important concept because it allows applications to hand objects to an external party without first copying those objects and still have a guarantee that the objects won't be m...

SQL Server amazes me!

Well, SQL Server amazes me, but not because I am impressed! Today I wrote an application that does the following: 01) Find all ZIP files in a specific folder 02) Open each ZIP file in turn 03) Extract an XML file from the ZIP into an array of bytes 04) Insert that data into a table There are 1,978 files in this folder and the XML within each ZIP file is around 2MB in size. I ran this app and was really surprised at how soon my PC started to crawl, it was so slow that it was taking over 10 seconds to switch between MSN and a Skype text-chat window. So I decided to monitor the process..... Importing the zip data into SQL Server took a total of 19 minutes and 15 seconds (this includes unzip time). What concerns me is that SQL Server's RAM usage went up to 830MB at its peak, this is what was crippling my PC. Twenty minutes after my app had finished SqlSevr.exe was still holding over 700MB of RAM, I then restarted my PC. SQL Server was using more RAM than I had available...

DaDa

Today my baby girl looked at me, said "DaDa" for the first time ever, and then giggled. What a great day! :-)

Delegates

I just remembered another technique for calling methods discovered via reflection! It is possible to convert a MethodInfo to a delegate and call it, this is just as fast as calling the method directly. So if you have a method that you call often which was discovered via reflection you should try this.... private delegate bool DoSomethingDelegate(object a, object b); MethodInfo methodInfo = type.GetMethod(.........); DoSomethingDelegate method = (DoSomethingDelegate) Delegate.CreateDelegate(typeof(DoSomethingDelegate), methodInfo); for (int i = 0; i method(this, this);

Onion, more on signals

I've been trying to think through every type of feature I can that people might want in an application, and then seeing if I can think up a way of implementing it using signals. A couple of days ago I thought up something I couldn't implement using the exact approach I had. I once wrote an app that had a treeview on the left hand side, the user could drill down to a customer of their choice and then when they clicked on that customer the display would update and show their details. This made me realise that a simple "SelectCustomer" signal would not be sufficient, what I actually needed to do was to have multiple SelectCustomer signals and indicate which customer to select. The changes I have decided to make are as follows: I will introduce a struct called SignalCreateParameters. This will hold a string property "Parameters" which may be used to automatically populate some of the properties of the created signal, ie the customer identity. The signal facto...

Onion, part 3

Image
Women can multitask No matter how many times you might be told "women can multi-task!" it's just not true, humans can only do one thing at a time. I don’t doubt for a second that my wife's brain can keep track of multiple subjects much better than my single task brain, but at any one point her brain is only concentrating on a single task! It's exactly the same for software. People may wish to deviate from their current task in order to fulfil some adhoc requirement, but that task is an interruption, it does not occur in parallel to what they were doing before. Once that interruption is over the user of your software wants to pick up where they left off. This is what a process driven (or "task oriented") approach to writing software is about. Process driven work flow A process in this context is a single task performed within an application in order to achieve a specific goal. The goal may be just about anything such as "Delete customer", ...