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copied!<p>The standard pattern is for your base class to implement IDisposable and the non-virtual Dispose() method, and to implement a virtual Dispose(bool) method, which those classes which hold disposable resources must override. They should always call their base Dispose(bool) method, which will chain up to the top class in the hierarchy eventually. Only those classes which override it will be called, so the chain is usually quite short.</p> <p>Finalizers, spelled ~Class in C#: Don't. Very few classes will need one, and it's very easy to accidentally keep large object graphs around, because the finalizers require at least two collections before the memory is released. On the first collection after the object is no longer referenced, it's put on a queue of finalizers to be run. These are run <em>on a separate, dedicated thread</em> which only runs finalizers (if it gets blocked, no more finalizers run and your memory usage explodes). Once the finalizer has run, the next collection that collects the appropriate generation will free the object and anything else it was referencing that isn't otherwise referenced. Unfortunately, because it survives the first collection, it will be placed into the older generation which is collected less frequently. For this reason, you should Dispose early and often.</p> <p>Generally, you should implement a small resource wrapper class that <em>only</em> manages the resource lifetime and implement a finalizer on that class, plus IDisposable. The user of the class should then call Dispose on this when it is disposed. There shouldn't be a back-link to the user. That way, only the thing that actually needs finalization ends up on the finalization queue.</p> <p>If you are going to need them anywhere in the hierarchy, the base class that implements IDisposable should implement the finalizer and call Dispose(bool), passing false as the parameter.</p> <p>WARNING for Windows Mobile developers (VS2005 and 2008, .NET Compact Framework 2.0 and 3.5): many non-controls that you drop onto your designer surface, e.g. menu bars, timers, HardwareButtons, derive from System.ComponentModel.Component, which implements a finalizer. For desktop projects, Visual Studio adds the components to a System.ComponentModel.Container named <code>components</code>, which it generates code to Dispose when the form is Disposed - it in turn Disposes all the components that have been added. For the mobile projects, the code to Dispose <code>components</code> is generated, <em>but dropping a component onto the surface does not generate the code to add it to <code>components</code></em>. You have to do this yourself in your constructor after calling InitializeComponent.</p>

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