I have written an application that uses await async
works very nice
i have been asked to install it on a windows 7 machine and
i am afraid it won't work due to .net issues
if the .net is 3.5 what are the recommended ways of action?
There is no way to use async/await in .NET 3.5. You have a few options:
Convince them to let you install at least .NET 4.6. It really won't interfere with anything using .NET <= 3.5 right now.
Change your code to .NET 3.5 and just make it work (some features have Begin and End methods to achieve some sort of asynchronous operations, but not all)
Change your code to use .NET Core (and target .NET Core) so you can use all the newest stuff, without having to update the .NET Framework (you copy over only the .NET Core DLLs that you use into the application's folder). Read about self-contained deployments here.
Related
I have .Net framework apps, that are intended to run only on Windows, now and forever.
I am thinking about upgrading them to .Net 5 or .Net 6, and target them to net5.0-windows (or net6.0-windows). From MS website it says that
net5.0-windows will be used to expose Windows-specific functionality,
including Windows Forms, WPF and WinRT APIs.
Does that mean that my .Net framework apps can be recompiled in .Net 6, as long as I specify the net-windows target and the csproject upgrade and compilation is successful, the program will just work? I just intend them to run on Windows, now and always.
My apps also consume a lot of .Net framework 2.0/3.5/4.6 dlls ( mostly they are involved with OpenGL and other graphic things), which I can only assume to have no general port to .Net 5 or .Net 6, and which the source code is no longer available even to me ( they are from close-source third party providers).
Does that mean that my .Net framework apps can be recompiled in .Net 6,
Yes
the program will just work?
Most likely it will, but one should do a full regression test to verify.
My apps also consume a lot of .Net framework 2.0/3.5/4.6 dlls
If you can't migrate to .Net 4.8, then chances are slim that one can be able to migrate into .Net core.
( mostly they are involved with OpenGL and other graphic things), which I can only assume to have no general port to .Net 5 or .Net 6
Each one has to be taken on as a case by case basis; you may have just actually answered your own question. Say Goodnight Gracey...
What may better serve you is to create a docker container which will serve up the older versions of these app(s) which has the target version of the frameworks which currently work.
Unfortunately there is no definitive answer to your question, as it will depend (no pun intended) entirely on what your dependencies are.
.NET 5 was intended to be the unification of classic .NET Framework and .NET Core and in many cases it will just work.
Speaking from experience, in many cases it is easier to create a clean project in the new framework, copy all the existing files from the old project then re-add NuGet and project references. I have done this successfully for Console Apps, Test Projects and even a WinForms app 15-20 project dependencies to .NET 4.8 projects and it has worked out of the box - albeit with a compiler warning about the .NET 4.8 dependencies.
However I have also come across at least one missing / changed API between 4.8 and 5.0 - BeginInvoke. A blog post here describes it in more detail. Sometimes there are also issues with NuGet versions.
The closest thing to a definitive list online is the MS Doc "Changes that affect compatibility" and in particular the Breaking changes for migration from .NET Framework to .NET Core section. I'm not sure the is a better "answer from a reputable source" out there.
As for your .NET 2.0 / 3.5 / 4.6 dlls I don't think there is anyway of knowing without trying. There are simply too many unknowns, especially as they are 3rd party dlls. If I had to guess it would be that at least one won't work, whether you can find an updated version or how much work an alternative library will be to incorporate will be impossible to tell
As for net5.0-windows, it's basically a fudge. While the goal of everything .NET 5.0 onwards was unification and cross-platform everything, they couldn't get all the work done in time. I read a blob post about it, which I can't find right now, but basically WinForms in particular is very closely tied to some underlying Windows only APIs. Maybe .NET 7.0?
I'm working on an old project. It was built by others long time ago, and it was built on .Net 2.0. Now, I need to add a new feature to it. However, coding wise, the new feature is supported by API/Class based on .Net 4.0. Obviously, it has to reference some new dll based on .Net 4. So, I made 2 versions of the program. One is for .Net 2.0 which does not have the new feature, and the other is .Net 4.0.
Now, the project manager asked: is it possible to make these 2 versions into ONE version? so in the code, it detects the .Net version, and then decides whether enable/disable the new feature.
If the user had .Net 4.0 installed, this should not be a problem. HOWEVER, there are some users, they are still using old windows servers which only have .Net 2.0 installed, and because of their work, install .Net 4.0 and reboot the system will be a problem. So, basically, this means the program has to be able to run on .Net 2.0.
Is this possible? How to do it? Any suggestions?
Thanks
****** add more info
I can detect .Net version. but I want to know how to do this:
If on the user's system, it is .net 2.0, run the code supported by .net 2.0 only; if the user's system is .net 4.0, run the code supported by .net 4.0.
Thanks
You need to target a .NET framework when doing a build. You're going to need to create 2 separate builds.
Pretty self-explanatory question, but here's a bit of context:
My app (C++, unmanaged) has a feature written as a C# app. This feature is only available when we know .NET is installed. So, must I maintain separate versions of this C# application for each framework version we want to support, or will a lowest-common-denominator of .NET 2.0 work (thus, if we detect any framework installed >= 2.0, we know we will be OK)?
Note that I prefer to just maintain a single .NET 2.0 version of our C# app.
You can assume that .net 2.0 apps will run on the 4.0 runtime.
See: http://msdn.microsoft.com/en-us/library/ff602939.aspx
The .NET framework dependencies page for .NET 4 on MSDN says that yes, you can count on it:
You do not have to install previous versions of the .NET Framework or
the CLR before you install the latest version; each version provides
the necessary components.
Yes, if you write and build your application against .Net 2.0, it will work with all versions going forward.
Yes... (.net 2 will work on .net 4)
I met a problem with mixed-mode assemblies like SharpSvn, which needed CLR v.2 to run, while my app was compiled for .NET 4, so we had to install both versions of the framework.
Still I believe it's not your case.
yes it has back compatibility assured , i have done this with .net 3 & 3.5sp1 and they are currently running on .net 4 without any problem.
Greetings all,
This has confused me ever since I first started coding in C#. My goal is to create an assembly that will run on the most recent .NET framework the user has, whatever that may be. I don't want to require .NET 4 to be installed, but I want to use it if the user has it, and more importantly, I want it to still work if the user has only .NET 4 and nothing below. I'm beginning to suspect this is not even possible.
I don't really understand what I'm selecting when I change the "Target Framework" in Visual Studio. Does that mean "will be compatible with this version and up"? Or "will be compatible with only this version"? It seems like it's the latter so far; my tests in virtual machines show .NET 4 targeted assemblies failing without .NET 4, and .NET 3.5 targeted assemblies failing without .NET 3.5. Is there no way to set this so I can achieve maximum compatibility?
UPDATE: To clarify, I have a program that targets .NET 2. The posters here seem to indicate that it should load with .NET 4. But in an environment with only .NET 4 and nothing before it, it fails to load.
UPDATE2: Okay, figured it out, but it's far more complex than the posters here seem to think. I'm opening a different question to discuss the intricacies, but the short version is, you need an app.config with <supportedRuntime version="v4.0" /> in it if you want to run non-.NET 4 assemblies on .NET 4. They won't load without it.
The frameworks are designed to be backwards-compatible; if you have a program written in .NET 2.0, you can run it in the 4.0 runtime, because none of the frameworks ever remove functionality that a prior version had (which is why we still have the non-generic collections like ArrayList, even though they're deprecated in favor of generic collections). However, the reverse is not necessarily true; a 4.0 app is not guaranteed to run in 2.0, because it MAY take advantage of new features of the new runtime that are not available in prior versions. In any case, if you want your app to attempt to run on runtime versions it does not specifically target, you must specify that in the app.config using SupportedRuntime elements.
To answer your specific question, you can do what you want with the following basic procedure:
Develop your app to target the EARLIEST framework version that you want to support. This will disable access to newer features of newer runtimes (like Linq in 3.5, and dynamic typing in 4.0) ensuring your app will not require any feature that cannot be provided by any of the supported runtimes.
Specify the frameworks that are acceptable to your application by using the SupportedRuntime element in your app.config file. This will tell the native code that initializes the runtime in which your app will run that if it can't find the targeted version, any of the others are acceptable. I believe the behavior is to look for the targeted framework first, and if not available it should use the newest supported runtime.
.NET is backward-compatible, this means if you select .NET Framework 2.0 as target framework, it will run on installed version 2.0, 3.0, 3.5 and 4.0.
But if you select e.g version 4.0 as target framework, it will only run if you have version 4.0 installed.
I believe this is supposed to be whatever version you select and upwards. So if you target 2.0 framework, it should work if client has 2.0, 3.0, 3.5, or 4.0 frameworks installed.
You are also selecting language features when you pick this, so I know of no way that you would be able to use 4.0 framework features using an application targeting 2.0 framework. Even dynamically loading assemblies doesn't work, try loading a dll compiled to 4.0 from a 2.0 application, it won't let you.
Here is how targeting works: If you target .NET 3.5, it will not run if user does not have .NET 3.5. It will run if user has any higher version.
For maximum compatibility, choose .NET 2.0, it will run even on .NET 3.5, 4.0 and so on.
However, you might loose out on new features of .NET such as LINQ etc.
http://msdn.microsoft.com/en-us/library/bb398197(VS.100).aspx
Can I still target .NET Framework 2.0 in VisualStudio 2010?
Our clients use a vb6 version of our software.
We are upgrading them to a .NET application written in C#...
Is there less bulk using .net 2.0 than .net 3.5?
My definition of less bulk would be: Smaller size, smaller installation time, etc.
Most of them probably already have 2.0 anyway.
I only ask because I would like to take advantage of LINQ in 3.5.
For taking advantage of LINQ, you need 3.5 (unless you want to use LINQBridge with 2.0).
For a smaller installer, .Net 3.5 Sp1 has a new feature called "Client Profile".
The .NET Framework Client Profile setup contains just those assemblies and files in the .NET Framework that are typically used for client application scenarios. For example: it includes Windows Forms, WPF, and WCF. It does not include ASP.NET and those libraries and components used primarily for server scenarios. We expect this setup package to be about 26MB in size, and it can be downloaded and installed much quicker than the full .NET Framework setup package.
Is not installing .NET 3.5 just to save a few Mb really that much more important that gaining a huge increase in productivity with LINQ and other .NET 3.5 features?
Why start off behind in technology?
The .Net 3.5 runtime is ~50Mb. The 2.0 runtime is ~23Mb.
But if you control the deployment or installation, that really shouldn't be an issue. This is especially true for 'clients' vs 'customers', and the word client involves and on-going, personal relationship. If it comes to it, send them a CD. Then anything under 700Mb is all the same.
Check out LINQBridge:
http://www.albahari.com/nutshell/linqbridge.aspx
Adding LINQ support to .net 2 (.net 3.5 still uses CLR 2.0).
.NET 3.5 is .NET 2.0 + more libraries and extensions, so yes, the install is bigger. In my opinion however, it is very much worth the extra bulk because of the extra stuff it gives you.
If it's a VB6 app, you should check which Windows versions the app is currently used on, and select the .Net version accordingly. AFAIK 3.5 does not run on W2K.
If you would like to take advantage of LINQ, then go for 3.5! I find there's not more 'bulk' when using it myself, but unless you want to use LINQ, then either is fine.
Keep in mind that certain OSes (Windows 2000 Server) won't let you install .NET 3.0 or 3.5, so you may have to stick with 2.0 for that reason.
I would suggest that you go straight with visual studio 2008 and .net 3.5 sp1,
2.0 is the basis of 3.5 and you can easily start using 2.0 and then start to use 3.5 functionalities.
Furthermore 3.5 SP1 also brings tweaks to the 2.0 framework which are nice to have.
I suggest you to go directly to 3.5 because you will be less far away (in the future ... in 3-5 years) to change to other version of framework. If in 5 year .Net is at version 5, the jump will be smaller to do. So, VB6 to 3.5 is what I suggest you.
The size of the framework is not very high, less than 60 megs... not a big deal now I think.
Also note, depending were you install the .NET framework it might be irrelevant how much extra bulk there is. The .NET Framework installs are relatively small in modern terms.
As for LINQ, it will save you a lot of time and effort, and offers a quick way to get at data. However it also depends on the clients the application will be distributed out to.
I'd say at that, go with 3.5 unless there is another major roadblock on the clients for whatever reason.
As others have pointed out, the .NET 3.5 install is longer and larger than .NET 2.0. Keep in mind that .NET 3.0 and .NET 3.5 are both extensions on top of the .NET 2.0 CLR.
I would still say upgrade from VB6 directly to .NET 3.5 (actually .NET 3.5 SP1) and VS2008, as long as your client operating systems support that version of the Framework (otherwise you will need to choose the lowest common Framework version, which very well may be .NET 2.0). You will save yourself a lot of time/effort in the long run.