We are writing an application that has to run on Windows 7... and we can't install a new version of the .NET framework on those client machines. As the developer, I want to use all the fancy new C# 6.0 language features, and if I understand correctly, the language and the framework have been decoupled.
I just need clarification: If I target C# 6.0 in my application, will the code still run correctly on a Win7 client with .NET 4.0 as the highest framework version?
Yes, you can use a C# 6 compiler while targeting an older version of .NET. The way this usually works is that you have a newer version of Visual Studio and target it at a specific .NET version. For C# 6, this means VS2015. You will be able to use any new C# features, as long as they don't rely on .NET libraries. In particular cases, such as if you want to use async stuff, there are backward compatibility libraries available.
You could also use csc.exe (C# compiler) directly, and bypass Visual Studio.
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My project leader insists on using Visual Studio 2005 which only targets the .NET 2.0 framework and only supports C# 2.0 syntax.
He insists that the 2.0 framework has higher compatiblity and performance for older computers. By old, I mean 5-8 year old Windows XP machines.
Assuming we only support a minimum of Windows XP / Server 2003, is there any advantage at all to using .NET 2.0?
I am pretty sure that even targeting .NET 2.0 we can take advantage of C# 3.0 syntax in our code (lambdas, auto-implemented properties, etc.) if we upgrade past VS2005.
.Net 2.0 is considered to be more widely deployed, but 3.5 isn't far behind any more. However, that's no reason to limit yourself to Visual Studio 2005 or C# 2.0. Visual Studio 2010 can target .Net 2.0, and use C# 3.0 features when it does so to boot.
.NET 2 is no longer supported by Microsoft. Well, Microsoft makes the terms tougher to explain. For Windows XP and Windows Server 2003, you have to at least use .NET Framework 3.5 SP1,
http://blogs.technet.com/b/lifecycle/archive/2010/04/30/net-framework-3-5-sp1-and-later-now-supported-as-part-of-microsoft-windows.aspx
so that you can receive assistance from Microsoft support team.
Therefore, I see no reason to stay on .NET 2.
"the 2.0 framework has higher compatiblity and performance for older computers" is a joke for me. When you lose support-ability from Microsoft, you lose everything.
Normally, people who would like to use the older version is mainly because they think the old one is more stable and better to production.
But .NET 2.0 is quite out of date already, and .NET 3.5 and .NET 4.0 have been proven to be very stable and make things easier. (such as LINQ, you can try functional style programming via it, very fluent and productive)
For the IDE part, Microsoft rebuild the visual studio 2010, it is more stable and productive, and it is also can target .NET2.0 if you want.
So, why not use Visual Studio 2010 instead of 2005, even if your project is purely .NET2.0, the former also has downward compatibility.
I am interested in C# windows application development. But now that I have shifted to Ubuntu I am no longer able to do it. Is there a way other than virtual box to develop a C# windows application in ubuntu??
Well there's the Mono Project but if you want the Microsoft .NET implementation you need Windows.
You might be interested in Mono Project.
It is an open source, cross-platform, implementation of C# and the CLR that is binary compatible with Microsoft.NET. However Mono is not totally up-to-date with lates releases of .NET Framework. It is a mix of .NET 2.0 - .NET 4.0 features.
The Mono project focuses on compilers and runtime libraries and does not directly provide an IDE like Visual Studio. Check here to check available solutions.
I had a request to write a dll library using C#, it should be build under .NET 3.5.
I've build the library (it's a simple TCP client) using Visual Studio 2005 with .NET 2.0.50727.
I'm assuming that I can not deliver this library since it's built against wrong .net
I have more .NET versions installed on my development machine but it looks like I can't switch the .net in properties like JDK versions in eclipse for a particular project.
Is the only proper way of doing this is installing Visual Studio 2008 Express with 3.5 .NET?
Or some C# sdk with appropriate compiler (the thing is that I don't know the syntax for the c# compiler and NANT would be pain in the ass at this stage)?
cheers
P.
As jgauffin already mentioned your .Net 2.0 assembly will work fine in .Net 3.5.
And switching to another .Net Framework is just downwards possible.
So with VS2010 you can built against .Net 4, 3.5, 2.0 and 1.1
With VS2008 you can built against .Net 3.5, 2.0 and 1.1
With VS2005 you can built only against .Net 2.0
With VS2003 you can built only against .Net 1.1
So if you really need it just go and download it from here.
3.5 is just 2.0 with additional libraries. Your DLL will work fine from a .Net 3.5 application.
I might be wrong, but I think that 3.5 was introduced with Visual Studio 2008 and cannot be built against with 2005. That's why you can't switch version.
Development Environment :
- VS2010
- .Net Framework 4.0, 3.5, 2.0
Staging and Production Environments:
- .Net Framework 3.5, 2.0
The project I'm working on is targeting .Net Framework 3.5. And today I used optional parameters feature, which is new to C#4, in this project and it worked fine. I think VS2010 is using C#4 compiler and is compiling the method with optional parameters to corresponding overloaded methods in IL.
I want to know if I can use all new C#4 features as well.
You cannot use is the dynamic feature. This relies on the C# runtime and DLR DLL's which are only available on the 4.0 version of the .Net framework. Versions of the DLR are available for 3.5 but I do not believe they are compatible with the one required by the C# compiler.
Additionally you cannot use NoPIA / Embedded Interop Types in a down targetted scenario. This feature requires CLR support that was added in 4.0.
What's great about down targeting in Visual Studio 2010 though is you don't have to be aware of every limitation. If your projects are set to down target 3.5 and you use an incompatible feature, Visual Studio will produce an error.
I bumped into this a couple of weeks ago actually. I used optional parameters even though the project targeted .net 3.5. You need to be very careful of this because if you install the application on a computer that only has .net 3.5 runtime installed then your program may not run. In my case, I used the optional params and the nightly build server only had 3.5 installed so the build failed.
Hey guys - I just wrote an app using c# and ready to deploy it. Never deployed a c# app before.
I deployed it and VC# outputted a .application file, application folder, and an installer. One of my users ran the installer (Windows 7) and was prompted to download/install the .net framework - which took upwards of 10 minutes. This is not acceptable for how simple my app is.
Moreover, I will need this app to be able to run on mac osx and linux if possible. Should I have wrote this in Java instead (poor planning on my part). What are my options?
C# is compiled to bytecode that runs on the CLR, the virtual machine that's at the core of the .NET framework. So yes, you need the .NET framework to run that.
Most current versions of Windows (XP, Vista, 7, etc.) come with some version of the .NET framework pre-installed, so your users don't have to download and install it. However, you might have used a version that's not already installed on the computers of (some of) your users.
For Linux and Mac OS X there is Mono, which is an open source implementation of .NET, but it does not contain everything that Microsoft's .NET contains, so your program might not work fully on Mono.
Using Java is not a real solution in the sense that your users would need to download and install the JRE (Java Runtime Environment) to run Java programs, very similar to the .NET framework. An advantage if you'd have used Java, is that Java is much more cross-platform compatible than .NET (Microsoft has no real interest in making .NET run on anything else than Windows).
.NET apps require the .NET framework. Java apps require the JRE. Your app is simple because .NET has done a lot of the work for you. A lot of companies write desktop apps in C++, but you will have to be mindful of cross-platform issues.
Yes, with any language that compiles to run on a managed runtime (.NET or Mono CLR, Java JVM) you will need to have that runtime installed. A C# application can compile to run on Windows on the .NET CLR, or on all the platforms you mention to run on the Mono runtime instead. Alternatively, a Java application would compile to run on the Java JRE, which is also compatible with all the platforms you mention.
So with either language there is potentially this extra installation overhead, and with either language you can achieve what you want.
You'll need to have .NET installed on your client's system in order to use your application.
As for running cross-platform - depending on how your Application is written, this can be simple or difficult.
You may want to look at Silverlight. This is directly supported on OS X and works on Linux via Moonlight.
Another alternative is to use Mono to run your .NET application on other platforms.
A C# app will need an implementation of the CLR (.NET) running on the local machine in order to run. A Java app will need an implementation of the JVM so it is really no different. On Windows, I would expect most people to have a .NET install.
Take a look at the Mono project as far as running it on Linux and Mac:
http://mono-project.com/Main_Page
One thing you can consider is using an older version of the .NET framework to ensure that the greatest number of people have it installed. I would use .NET 3.5 or even 2.0 if you do not need fancy new features. That would have been installed already on Windows 7 for example.
Since the Windows 7 user had to download the framework I assume you are currently targeting .NET 4 which means you must be using Visual Studio 2010 (or an express version). Here is a link that tells you how to target a different version of the framework:
http://msdn.microsoft.com/en-us/library/bb398202.aspx
One quick note about Mono, it is an excellent cross-platform option but it does not support the Windows Presentation Foundation (WPF) GUI framework at this point. You will either have to use Windows Forms or create different front-ends for different platforms.
If you want to create a Linux GUI (also available on Windows and Mac) you can try GTK#:
http://www.mono-project.com/GtkSharp
For a Mac native GUI you can check out MonoMac:
http://mjhutchinson.com/journal/2010/06/09/monomac_in_monodevelop
An excellent IDE for cross-platform .NET development is MonoDevelop (it will read your VC# project files):
http://monodevelop.com/
Like Java, .Net languages need a runtime installed. The full .Net framework is sometimes too big for small applications, so there is a smaller version of it call the compact framework with a smaller footprint that will install and download faster. You can read about it at http://msdn.microsoft.com/en-us/netframework/aa497273.aspx. As noted by other answers most current versions of Windows come with various versions of .Net framework, so this installation may not be needed for every user.
As far as your cross platform needs go Mono allows for running .Net applications on Linux, I am not sure about running them on OSX. My assumption is you can not. Unfortunately your cross platform requirements made .Net a bad choice, and you should have gone with Java.
Other people gave you complicated answers. Well here's my simple answer. .NET framework is needed to run .NET applications and so do Java need JVM (as MCain said). Starting with Windows Vista, Microsoft includes .NET Framework built inside Windows. And in addition, .NET have versions, from 1.0 to 4.0. With Vista and Windows 7, .NET 3.5 is installed by default. I think your app is targeted for .NET 4.0 which is why a Windows 7 user needed to install .NET framework. For me, if I have to write a simple program, I'll use .NET 2.0 (later version = larger libraries, etc) so that my users (if they are Vista or Windows 7) don't have to install .NET again to run my software. You can choose which version of .NET you will target from New Project Window in Visual Studio.
You can change the target framework in the properties tab. If you start a project in VS2008 the default is .net 3.5 and for VS2010 it is .net 4.0. If you don't need the advanced features you can change your target back to 2.0 which should be available on most computers by now (I would guess far over 90%). Be sure to remove dependencies which are not available in 2.0 (like System.Linq, System.DataSet.Extensions) and the accociated imports (But the compiler will tell you what to do).