I am working on a project that is currently using an early pre-release .net 4.0 version on HttpClient in System.Web.Http namespace. We know that this version causes conflicts with .net 4.5 version.
We are thinking of upgrading to Visual Studio 2012 and we know that this is going to install .net 4.5 (which we dont currently use). My question(s) is, how drastically different are the two version of the HttpClient class? Or, would the use of the latest .net 4.0 version of HttpClient be enough to get us to a stage where we could install .net 4.5 and not have any conflicts?
Cheers
NCBL
The two versions are identical from an API perspective and 4.5 is backwards compatible with 4.0 from a functionality perspective. The 4.5 version does support a couple new features on WebRequestHandler (ContinueTimeout & ServerCertificateValidationCallback) so avoid those.
You shouldn't run into any conflicts when using this library and running on 4.5. The 4.5 version has the same name as the 4.0 version and the framework will unify to the inbox version.
Related
In my school they use VS 2019. I installed the same because that was what was available at the time (community version for me, I think the same for my school).
I had a couple of issues with VS2019 so I uninstalled everything and installed 2022 version instead. I then began to use this for the last 2 weeks but when I tried to open my old files, I couldn't.
I did install framework 3.1 again and the code will enter runtime successfully, but I still can't see the code that I wrote. I don't want to re-install VS2019 because it kept on giving me issues with intellisense which I just couldn't fix.
Is there any way I will be able to open my old 2019 files in 2022? Also, will 2019 be able to open 2022 files?
The generic answer to this is mostly yes but maybe no depending on your specifics. That's not a helpful sentence, so let me explain.
For the most part, Visual Studio solutions and projects are cross-compatible1. This means that if you have a project from one version, you can usually open it in another version without issue. The major caveat to this is the range of frameworks supported by each VS version may be different. VS will often be able to open the project, but might not be able to build and run it.
(Because you tagged this with vb.net, I'm limiting this to .NET versions. The same concepts may apply for other platforms.)
For example, VS2019 supports:
.NET version 5 (Visual Studio 16.8 or later)
.NET Framework versions 4.8, 4.7.2, 4.7.1, 4.7, 4.6.2, 4.6.1, 4.6, 4.5.2, 4.5.1, 4.5, and 4.0
.NET Core 3.1, 3.0, 2.2, 2.1, and 1.1.
And VS2022 supports:
.NET Framework versions 4.8, 4.7.2, 4.7.1, 4.7, and 4.6.2
.NET Core 6.0 Preview, 5.0, 3.1, 3.0, 2.2, and 2.1.
Note how VS2022:
DOES NOT support .NET Framework versions 4.0-4.6.1, or .NET Core 1.1
DOES support .NET (Core) 6.0 - which VS2019 does not
It is reasonable to expect that the next version of VS will stop supporting some versions while it adds support for new ones again, so this compatibility range will change with each VS release.
1: Each different type of project requires a Project System to support it. Occasionally, these may be dropped out of support like with the frameworks described above, but with the more severe consequence that VS will not be able to open the project at all. Some examples over time: Silverlight and Windows Phone projects, Setup projects, DNX (early .NET Core) projects, etc.
I'm not cleared in the specification of .NET Framework 4.0. As per my knowledge .net framework 3.0 required .net framework 2.0 and .net framework 3.5 required .net framework 3.0, so I'm not cleared that whether .net framework 4.0 required .net framework 3.5? Whether .net framework 4.0 is standalone or not? I had searched most of the Microsoft helpful sites, but not got anything on that topic. Guys, If you know anything please share.
No, every version of .NET has been standalone. You can install .NET 3.0 with no other version installed, ditto .NET 3.5, ditto 4.0, ditto 4.5 etc.
Now there have been fewer versions of the CLR than there have of the .NET framework overall, but that's a different matter - and doesn't change whether or not you can install .NET without installing anything else.
Likewise some versions of .NET effectively install over the top of others (installing .NET 4.5 when you've got .NET 4.0 installed replaces the .NET 4.0 libraries) but you can still install each version without installing anything else first.
Recently I'm heard about FluentMigrator and its features and really amazed about it and I want to use this in my new project in .NET Framework 4.5 and when I checked in github I saw that the newest release supports 3.5 and 4.0 and they didnt mention about 4.5 and I googled for any news about 4.5 with fluent migrator and I didnt get any satisfying result so I want to know is it possible to use Fluent Migrator with .NET Framework 4.5
Yes, .NET 4.0 assemblies will work in a .NET 4.5 project. The 4.5 CLR is a new version of the CLR but is backwards compatible with 4.0. See this StackOverflow question and this blog post from Scott Hanselman.
So if you have a class project which is set to target .NET 4.5 and add the .NET 4.0 version of FluentMigrator as a reference (or install the Nuget package) then it will just work.
For FluentMigrator there is no major benefit of having a .NET 4.5 package, due to having to support .NET 3.5, none of the new .NET 4.5 features can be used yet.
This is a two part question. I need both parts addressed for a complete answer.
Part I
I have a .NET 4.5 desktop app and I'm wondering if I can deploy it to Windows XP if, within "Requirements" in the app's Installshield project, I tick the ".NET 4.0 Full Package is Installed" checkbox instead of the ".NET 4.5 Full Package is Installed" one.
I read here that:
You can compile an application for .NET 4.5 and run it on the 4.0 runtime – that is until you hit a new feature that doesn’t exist on 4.0. At which point the app bombs at runtime. Say you write some code that is mostly .NET 4.0, but only has a few of the new features of .NET 4.5 like aync/await buried deep in the bowels of the application where it only fires occasionally. .NET will happily start your application and run everything 4.0 fine, until it hits that 4.5 code – and then crash unceremoniously at runtime.
So I know what the ability of my app to run on Windows XP with .NET 4.0 depends on. Let's assume for this question that my app won't crash as described in the above quote.
Part II
I also need to know what effect choosing ".NET 4.0 Full Package is Installed" instead of ".NET 4.5 Full Package is Installed" will have when installing the app onto a machine with .NET 4.5, but not .NET 4.0, installed. Will the Installshield installer see the installed .NET 4.5 package as .NET 4.0 and thus not complain? Or will it be picky and block the app's installation since specifically .NET 4.0 is not installed?
First thing you need to do is change the Target Framework version of your projects from 4.5 to 4.0 and rebuild. If you used any 4.5 specific feature then you'll now find out. You'll need to fix errors.
Part 2 is a non-issue, .NET 4.5 is a replacement for .NET 4.0. The installer is not going to uninstall 4.5 first so it can install 4.0, that would break all existing .NET apps on that machine.
I have an app that I've upgraded from 3.5 to 4.0. But not all my 3rd party assemblies are built on .net 4.0. How is it that I'm still able to reference those assemblies without any problems? For instance, if another assembly references system.dll 2.0, and my upgraded project references system.dll 4.0 how does .net handle this?
Obviosly this wasn't a problem upgrading between 2.0 and 3.5 because they use the same BCL and CLR versions, but 4.0 uses a completely different BCL and CLR right?
Here's an example. I have an app built using WF (Windows Workflow) in v3.5. I've upgraded the app to v4.0, but I wasn't required to implement all the breaking changes in the new version of workflow. It still using the old 3.5 version of WF.
.NET 4.0 can reference .NET 2.0 assemblies, but the reverse is not true.
.NET 4.0 assemblies support everything that 2.0 had, but adds in things like optional parameters, dynamic types, and etc...
So, since 2.0 doesn't have anything that 4.0 doesn't, 4.0 can easily support 2.0.
BCL and CLR are different but not completely different. Basically they worked hard to not break backwards compatibility.
You could also force your 3rd party assemblies to run under 3.5, as described in this post.