A day in the life of...

My computer was recently running out of disk space. I couldn't believe it, I have 175GB on my partition, how could I fill it so quickly? I was considering buying a 500GB external drive to store my home videos etc on (which is where I assumed all the space was being taken) and earlier today I nearly went out and bought one too! I just decided to check where all that space was being taken up. Here are the folders on C and their sizes in GB apps 2.76 data 40.7 msocache 0.7 otherdata 0.8 program files 9.16 program data 0.9 users 1.64 windows 13.8 That's a total of 70.46GB, but Windows was reporting 173GB in use! I ran scan disk etc, no luck! Where was all the space being used? The answer was System Restore! After reading this article I realised my restore data was using 90GB of data! What a waste! I have now limited it to 10GB maximum. Can you believe that? It's ridiculous! Luckily I have just saved myself £70!

When trying to add a service reference to my SilverLight project I kept getting this error message The contract name xxxxxxx could not be found in the list of contracts implemented by the service I looked around the web and couldn't find anything of any use (yes, I had added ServiceContract to my interface). The solution was really simple! In my Web.Config I had the wrong interface defined. IApplicationService was defined in another assembly, one I had added a namespace to, so I additionally needed to add the namespace before the interface name. All I then had to do was to add the following attribute to the service implementing the interface and it seemed to import fine. [AspNetCompatibilityRequirements(RequirementsMode=AspNetCompatibilityRequirementsMode.Allowed)]

A customer requested that instead of my NumericUpDown controls silently capping the input value within the Minimum..Maximum range it instead showed an error message telling the user their input is incorrect and that they need to alter it. I was a bit annoyed to see that NumericUpDown.Validating is never called on the compact framework, in addition there was no way to get the input value and either accept or reject it before it is applied to its data bindings. There's an article here which shows how to implement auto-select text when the NumericUpDown receives focus and I have been using it since Feb 2006. I decided to extend upon the techniques within it to implement the Validating event. My goal was to fire the Validating event before the value is applied to all data-bindings, but also to allow the programmer to read NumericUpDown.Value in order to determine the new value. To do this I had to replace the WndProc of the control so that I could handle the WM_UPDOWN_NOTIFYVALUECH

An app I am working on needs to be a single instance. It is associated with certain file extensions so that when I select a character or license file it will be imported automatically. When the user buys a character or license (etc) from the website it will be downloaded and opened, and then imported. Obviously it is a pretty poor user experience if they have to close the app, download, close the app, download... So what I really needed was a way to have the 2nd instance of the application to invoke the first instance and pass the command line parameters. Here is a simple solution I implemented using remoting. 01: An interface public interface ISingleInstance { void Execute(string[] args); } 02: A class that implements the interface public class SingleInstance : MarshalByRefObject, ISingleInstance {   private static object SyncRoot = new object();   private static Form1 MainForm;   static SingleInstance()   {     Application.EnableVisualStyles();     Application.SetCompatibleText

I have changed the DirtyObjectCatcher so that it initially only hooks Form.Disposed - Automatically disposes the DirtyObjectCatcher Form.Closed - Unhooks all additional form events (below) Form.Shown - To hook additional form events (below) ==Additional form events== Form.Activated Form.MdiParent.Activated Form.MdiChildActivate The additional events are to ensure that the DirtyObjectCatcher's undo block is moved to the top. The reason that these events are now unhooked is so that there is no strong event references from the application's main form (Form.MdiParent) to this component, keeping it alive. Now we only have long-term event references from the owning form itself. Really though this is just an added precaution against something I may not have thought of :-) The true memory saver comes from only holding a WeakReference to the owning form. Otherwise in an MDI application we have the following MainForm.MdiChildActivate->DirtyObjectCatcher->Form In such a case c

As a follow up to yesterday's post here is a list of problems I found... 01: The following code for some reason causes the form holding the DirtyObjectCatcher to remain referenced. if (Owner.MdiParent != null) { Owner.MdiParent.Activated += new EventHandler(MdiParent_Activated); Owner.MdiParent.MdiChildActivate += new EventHandler(MdiParent_MdiChildActivate); } The odd thing about this is that it really is the events that matter! I subscribe Shown, Disposed, Activated on the Owner (which is a form) and that doesn't cause the same behaviour. The reason is that the Owner normally gets disposed and takes out the DirtyObjectCatcher with it, however, if I have Owner.MdiParent events referencing DirtyObjectCatcher then the form will never get disposed because DirtyObjectCatcher has a strong reference to Owner. Maybe I should change it, but for now the Shown and Activated events seem to be doing the trick. 02: This one was a real pain! DirtyObjectCatcher creates its own Undo

Oh boy, what a nightmare! After days of messing around I finally found where the memory leak is in my app, it was in DirtyObjectCatcher! The DirtyObjectCatcher used to subscribe to the DirtyListService, so that it was notified whenever an object was made dirty. I experienced this problem... 01: User creates a "Call" to a customer site. 02: User edits a purchase order. 03: Save purchase order (merges the undo block to the Call undo block and closes the form) 04: Edit the purchase order again from the Call form The PurchaseOrder is already dirty so it wont get triggered again, this used to result in no constraints being checked etc and the possibility of entering dodgy data. The solution at the time was to have a static list in DirtyObjectCatcher private List Instances; whenever a new instance was created it would be added, whenever Dispose was called it would be removed. I then hooked into the cache chain and whenever a value changed I would call a static method on DirtyObjec