Constructors and Destructors

Question

As i know the Garbage Collector manages the allocation and deallocation of memory in C#. When i need to convert unmanaged code into C# what exactly should be done with constructor and destructor code?Should i convert it accordingly as in C# or leave it assuming GC will look after it? Please give the information at the earliest. Mail [email protected]

chrishornberger · Answer

Yes marking it up with IDisposable will ensure that it is called by certain objects within the framework. Mind you that's what the docs say. I've never found a list of those certain objects. Apparently alot of the objects in the framework have been coded to look for it and utilize it if it's there. But it's a good practice anyway. Handle all the stuff in your Dispose() that you would normally put in a destructor and whether it be from your code or from framework code it *should* be called. And jsut for giggles get used to using it within your own code. Wrapping the contents of your .Dispose() in try...catch will make it safe to call repeatedly. The objects will always get thrown away but not necessarily calling the ~ destructor... unless you're keeping a system level unmanaged resource open. Which means that although unlikely it's still possible to keep memory and resource leaks around.

avidgamefan · Answer

So as a general rule call .Dispose() where you would have called the delete in C++ etc.? Is there any particular reason to use IDisposable for your own objects? I mean you can always add a .Dispose() method. I suppose using the interface gives you the option of making use of it elsewhere should the need arise. The hardest thing for me to get past is the idea that the destructor may never be called. I think that's the key to understanding how to design the deallocation of resources. (I've done a lot in C/C++ so it's tough to un-learn this!) Gary

chrishornberger · Answer

You can generally do everything you want or need in constructors. As for GC it is recommended to simply make sure you clsoe any open resources (streams db connections etc) and let GC handle clean up for you. If you use any unmanaged resources at all (including unmanaged DB connections) you should implement the IDisposable interface and make sure to call its .Dispose() method on your objects where/when possible. Try to avoid formal use of destructors (~) and lean more towards the .Dispose() pattern. There are several books available that devote at least a chapter to GC and management. I'd say just wander by Borders or any other bookstore and try to take a read thru'.