Framework versions question

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Feb 9th, 2013, 04:49 PM
geek648

Framework versions question

I assume that backwards compatibility is built in? i.e. a .DLL compiled for v3.5 should be ok to use with a v4 project?

I ask because I'm about to play with some Open Source widget and their downloads page provides versions for .net 3.5 and 4. By the sound of it, they're not using anything specific to v4 (otherwise how would they produce a 3.5 ver?) ... so why provide both?
There is no forum for their project, or I'd ask there, but I'm sure you guys will have an answer :)

Thanks....
Feb 9th, 2013, 05:05 PM
4x2y

Re: Framework versions question

Quote:

Originally Posted by geek648

I assume that backwards compatibility is built in? i.e. a .DLL compiled for v3.5 should be ok to use with a v4 project?

I was think so too until i faced a problem running program targeted v2.0 in Win7 with NET 3.5 installed, so i downloaded v2.0 to run that program!!!
Feb 9th, 2013, 05:18 PM
dunfiddlin

Re: Framework versions question

You can assume it but don't presume it! [Oh I'm in a devilishly cryptic mood tonight!] Generally though, if there's one to match your preferred framework, use it. There'll be a reason for producing it, even if it's not obvious to you.
Feb 10th, 2013, 05:53 AM
geek648

Re: Framework versions question

Thanks, anyone else care to chip in with more technical detail?
Cheers
Feb 10th, 2013, 10:19 AM
Niya

Re: Framework versions question

Quote:

Originally Posted by 4x2y

I was think so too until i faced a problem running program targeted v2.0 in Win7 with NET 3.5 installed, so i downloaded v2.0 to run that program!!!

Interesting....As far as I've observed all versions of the framework serve as prerequisites for the next version. I.e You cannot have 3.5 without 2.0 or 4 without 3.5 etc.
Feb 10th, 2013, 03:40 PM
4x2y

Re: Framework versions question

Quote:

Originally Posted by Niya

As far as I've observed all versions of the framework serve as prerequisites for the next version. I.e You cannot have 3.5 without 2.0 or 4 without 3.5 etc.

Windows 8 comes with .NET 4.5 pre-installed and you have to install .NET 3.5 to run applications that require the .NET 3.5, read more...
Feb 10th, 2013, 04:25 PM
Niya

Re: Framework versions question

Hmm that is contrary. Clearly there's something I missed.
Feb 11th, 2013, 03:36 AM
geek648

Re: Framework versions question

Thanks, it's all very intriguing and puzzling. I thought I had a grasp on it, but now I'm very confused!
I'm keen to see what anyone else could contribute...
Cheers
Feb 11th, 2013, 08:04 AM
techgnome

Re: Framework versions question

If I remember right, the progression was like this:
FW 1.1 built upon FW1.0...
FW 2.0 was a break from FW1.0/1.1
3.5 added to 3.0 which added to 2.0...
FW4.0 was another "clean" break...

Originally each release of the next version of the FW was supposed to build upon the previous version... but that meant you would have to start with 2.0, and then apply each version... so MS has added occasional breaks when there's significant enough changes. I expect the next break to be with FW6.0

Going back to the OP, that's probably why they supplied both a 3.5 and a 4.0 version of the DLL.

-tg