Specify framework version for an app

[vbmom]

I'm using Visual Studio 2005 and my simple application wants to use .NET Framework 2.0. I assume this because when I run it on another computer it tells me it needs it to run. I rather just force my app to use .NET 1.0 or 1.1.

I've searched this forum and come up empty. I did find a post elsewhere explaining how application configuration files can help you achieve this but no details on how to do it.

It seems there should be a way inside the sophisticated IDE environment to tell the compiler this. Any ideas?

[mpdeglau]

I believe I have read about some hacks that will do it, but you shouldn't do it. If you want your application to run on 1.1 get VS 2003 if you want your app to run on 1.0 get VS 2002. Each version of VS developes for a specifc framework.

[vbmom]

So pardon my ignorance, but there's no "backward compatibility" between frameworks? 2.0 won't run 1.0 apps? Yikes.

[mpdeglau]

Correct. The frameworks have no knowledge of each other. There really can't be backwards compatability.
So for example an app was developed on 1.0 and the computer 2.0. In the app it uses a function provided by the framework that has since been removed from the framework. This would cause the app to not work.

[mendhak]

The 2.0 framework has different classes, and many of the methods that you may inherently use are different. Backwards incompatibility is inevitable with evolution.

[jmcilhinney]

It makes compete sense that .NET 2.0 apps can't use earlier Framework versions. Would you put a car engine in a plane and then expect it to take off? Do VB6 apps run with just the VB5 run-time files installed?

[mpdeglau]

Would you put a car engine in a plane and then expect it to take off?

I wouldn't mind doing the reverse.

[yulyos]

Hi,

I have in my computer only Framework 2.0 and the application
was build with Visual Studio 2003 in another computer.

Can the application run in my computer?

[jmcilhinney]

.NET applications will usually run on a newer version of the Framework, but there is no guarantee. Run OK under most circumstances and then crash unexpectedly. They may appear to be working correctly but be corrupting your data behind the scenes. They will never run on an older version. You should definitely install the correct version of the Framework for the apps you're running. There is no issue whatsoever with running multiple Framework versions on the one system. It has been specifically designed to work that way.