I have a basic server control that I've written using .NET 3.5. If I give that dll to someone who is running a .NET 2.0 application, will it work?
Unless you are referencing any DLL's included in .NET 3.0 or 3.5 then yes it should work because the CLR versions are the same in .NET 2.0, 3.0, and 3.5. I believe there may have been minor changes to the 2.0 assemblies ("red bits") but I'll have to double check.
You can even just change the project properties in Visual Studio to target .NET 2.0 to be sure. If your app doesn't compile then it wouldn't have run on .NET 2.0 anyway.
Scott Hanselman has posted about .NET 2.0-3.5 differences.
The first thing you should do is try changing the Target Framework to 2.0 and see if your Server Control project still compiles (Right click on the project, choose Properties, then change the Target Framework to ".NET Framework 2.0" and choose "Yes" in the "Target Framework Change" dialog). If it still compiles you're off to a fairly good start. Now compile it, add it to a new web site and check to see if it works.
Most of the time you'll probably find that your control won't be using any 3.5 specific features, so once you've tried compiling it against 3.5 you'll be good to go!
Related
I have a project that targets both .Net 2.0 and .Net 4.5. I built+published it successfully in Visual Studio 2013. The .Net configuration in the .csproj file still says
<TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
Yet, when I open the project in VS 2015, it targets .Net 4.5.
I have 2.0 available in the Target Framework dropdown:
when I click ".Net Framework 2.0" it gives me a popup saying
Changing the target framework requires that the current project be closed and then reopened.
Any unsaved changes within the project will be automatically saved.
Changing Target Framework my require manual modification of project files in order to build.
Are you sure you want to change the Target Framework for this project?
When I click yes, the target framework goes back to 4.5 and nothing else happens.
I've tried reopening the project and VS, with no luck.
I've tried running the .Net 3.5 installer (which apparently includes 2.0), but it says I need to use "Turn Windows Features on/off"
I've ensured the .Net 3.5 Windows Feature is enabled.
And now I'm out of ideas. Has anyone else encountered this?
Running Windows 7.
In case, the .NET Framework 2.0 is corrupted, use the .NET Framework setup verification tool: https://blogs.msdn.microsoft.com/astebner/2013/11/06/net-framework-setup-verification-tool-and-cleanup-tool-now-support-net-framework-4-5-1/ to verify and once it found any corrupted, you can use the .NET Framework Repair Tool: https://www.microsoft.com/en-us/download/details.aspx?id=30135 to repair it.
Or under ‘Turn Windows Features on or off’, uncheck .NET Framework 3.5 (includes .NET 2.0 and 3.0), then check it.
As Hans Passant mentions in the comments, I apparently(?) edited the .csproj to use different frameworks for different configurations. I swear this didn't cause any issues in VS 2013.
But in any case, I verified using ILSpy that the .dll being generated is .Net 2.0, even though the dropdown says 4.5. So I guess all's well that ends well?
I have a project in .Net 4.5, however when I try to add a framework reference all that is available to me are 4.0 options. Why is this happening and what can I do to get the 4.5 references options?
Thank you in advance.
That's another direct result of .NET 4.5 in place upgrading .NET 4.0. Th assembly version you saw in VS should not change, while the actual file version if you check in Windows Explorer updated.
This kind of design gives maximum compatibility to applications as they can load the new assemblies just as usual. Assume Microsoft changed the number to 4.5 as you desired, such applications would throw FileNotFoundException which can be quite harmful.
I'm writing a C# class library, which will be used in a project that runs on .NET Framework 1.1. However, I'm using Visual Studio Ultimate 2010, which doesn't provide tooling for version 1.1.
Is there a static check that I can perform inside VS2010 to see that the code is 1.1 compatible?
The csc has the ability to check for syntax compatibility. Use the langversion flag in some post build step to check for program compatibility with ISO-1. I would recommend keeping a separate project for the .NET 1.1 library since the conventions after .NET 2.0 greatly diverge.
There is a problem in backward compatibility in .NET Framework if you build your application in .NET 4.0 than you can not except that this version will work in .NET 1.1 Framework.
A lot of functions are new or obsoleted.
I think a good idea is to build the project in differents target vesions.
Check this information:
http://msdn.microsoft.com/en-us/library/ff602939.aspx
I have a .NET application that I built in 4.5, which has references to a bunch of libraries that were built in 4.5, which themselves have references to 4.5, etc. A user group that I'm trying to distribute the application to is having problems running the executable because they have 4.0 installed; in particular, they're getting a MissingMethodException:
Method not found: 'System.Type System.Runtime.InteropServices.Marshal.GetTypeFromCLSID(System.Guid)'.
Because we may have trouble getting each user upgraded to 4.5 (as none of them have admin permissions on their machines and this would require a separate upgrade request for each user), I'm looking at finding an easy way to rebuild the project as 4.0. This seems to require that I rebuild every library and its referenced libraries in 4.0; is there an easier way to do this than going through each library one by one and building a 4.0 version? I'm thinking maybe like a one-click option for "Rebuild all referenced libraries in target framework" or something like that.
If you have dependencies on .Net 4.5 DLLs then you will need to also get .Net 4.0 versions of those if you want to successfully downgrade your project. A .Net project can only reference .Net DLLs up to the same version of .Net as the referencing assembly.
The easiest way to do this is to use something like NuGet to manage your dependencies. Note that when you change the target framework version of your project in VS you will need to uninstall and re-install dependencies with NuGet as NuGet does not automatically do this for you when you change the target framework version.
Of course if all the dependencies are to your own code and you aren't publishing this through a dependency management system like NuGet you will need to downgrade all your other code to .Net 4.0 as well
When I use Visual Studio, I right click on the project, change the framework, fix the References and recompile. Usually straight forward.
Please, have a look at this MSDN page to correctly switch your project to a lower target framework without problems! It is a little bit outdated for what concerns versions, but the process is the same described!
This is based on my experience. I had an application initially created in .net framework 4.5 but I wanted to convert it in .net framework 4.0. I created new project initially created 4.0 and then I did copy and paste of all the forms and controls of my previous application and it works. Framework 4.5 is using Aero2 and 4.0 is Aero... Good Luck :)
This would be a real pain to try to duplicate, so I'm hoping someone has a quick answer...
Suppose I have a .NET 4.0 application, with a reference to a .NET 2.0 library (SharpZipLib in this case). This of course works fine on a normal machine with .NET 2.0 and 4.0 installed.
If the server running this application has only .NET 4.0 and not 2.0 (or 3.0/3.5 etc.), what do I need to do to allow the .NET 2.0 library to run properly?
From what I've read, it looks like I may be able to put in a config setting for supportedRuntime, but I'm not quite understanding what exactly that does.
Will a config setting work, or would only .NET 4.0 libraries function in this environment?
(This is a hypothetical environment - I don't plan on ever having my own servers with 4.0 and not 2.0, but if someone is crazy enough to do it, I want to be able to support them).
Thanks
The CLR can load older assemblies in the .net 4.0 framework.
Here's a good read:
http://msdn.microsoft.com/en-us/magazine/ee819091.aspx
EDIT: updated quote from article. Particularly notice the bold
The .NET Framework 4 runtime—and all future runtimes—will be able to
run in-process with one another. While we did not back-port this
functionality to older runtimes (1.0 through 3.5), we did make sure
that 4 and beyond will be able to run in-process with any single older
runtime. In other words, you will be able to load 4, 5 and 2.0 in
the same process, but you will not be able to load 1.1 and 2.0 in the
same process. .NET Frameworks 2.0 through 3.5 all run on the 2.0
runtime and so have no conflicts with one another, as shown in Figure
2.
From http://neilblackburn.blogspot.com/2009/10/net-framework-40-backward-compatibility.html (and, transitively, http://mtaulty.com/CommunityServer/blogs/mike_taultys_blog/archive/2009/08/03/installing-net-framework-v4-0-and-running-net-2-0-3-0-3-5-3-5sp1-applications.aspx):
Now, I knew that you can’t just take a 3.5 Service Pack 1 application
and run it on the V4.0 CLR. It needs a V2.0 CLR or reconfiguring with
a <supportedRuntimes/> tag in order to bend the application to run on
the V4.0 CLR and that bending might be something that you don’t want
to do.
From the link in bryanmac's answer (In-Process Side-by-Side):
This means that if an application is recompiled to run against the .NET Framework 4 runtime and still has dependent assemblies built against .NET 2.0, those dependents will load on the .NET 4 runtime as well.
That can mean, however, that there may be bugs due to being run on a different runtime.
If you have the source to SharpZipLib you could just rebuild it as .NET 4.0