64 bit application development

[rkharikrishnan]

Hello guys
i have a developed a C# desktop application in MS visual c# express edition 2008 and SQL express 2005. I have done development on a 32 bit system and published the work to a web server, from where the users can install application to the system.
I want to make this work in 64bit system also. Is there any additional work that I should do in the current software for working in 64 bit environment?

Thanks and regards
Hari

[vekipeki]

If you are not using COM and unsafe stuff, pure managed code should build for 64-bit without changes.

If you're using 32-bit COM interop, you will have to build a 32-bit target (which will run in WOW64 on 64-bit systems). If you're using unsafe pointers, then you will most certainly have to add a couple of #if/#endif blocks here and there. Also, if you are passing information to 32-bit managed apps using .Net binary serialization, it won't work unless you implement your own serialization format.

Check this link for some guidelines, here is what it says:

As mentioned earlier, if you have 100% type safe managed code then you really can just copy it to the 64-bit platform and run it successfully under the 64-bit CLR.

But more than likely the managed application will be involved with any or all of the following:

* Invoking platform APIs via p/invoke
* Invoking COM objects
* Making use of unsafe code
* Using marshaling as a mechanism for sharing information
* Using serialization as a way of persisting state