We are developing a cross platform mobile application using Xamarin. I have noticed there are different ways of structuring your code using Shared code or PCL/.net standard.
I attempted to use .net standard and what i have found is that it doesn't include all the libraries such as using ado stuff , datatable/datasets using system.data. Or using system.net for example. Other functions have less overloads and seems that its a stripped version of .net to work across platforms. Is there any way to add this functionality or use a broader range of .net?
You are correct - .Net Standard and .Net Core are stripped down versions of the full .Net framework. They contain only features that can be used on all platforms (Mac, Android, iOS, Linux, Windows, etc.)
The full .Net framework only needs to work on Windows, so there are additional things that you can do based on the fact that there is less complexity in implementing and that the code base is more mature (cross platform is still pretty new by C# standards). To the best of my memory, System.Net should work if you have your references correct, but System.Data will not (or at least direct database access is not possible)
You can regain some functionality through NuGet packages, but it won't be the same as using WinForms or something like that...
My best advice would be to program against an API. You can use a web server that runs on the normal (full) .Net framework, and does all the heavy lifting using all the .Net features that you are accustomed to. Your Xamarin app would send and receive data from the API and basically provide a mobile front end for whatever you are doing. This approach makes sense for most apps anyway, and is generally what you would be doing anyway if you used Swift and Java to create separate iOS and Android apps.
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Currently, we are developing a .NET Standard class library that will be used by different Xamarin.* platforms.
I was wondering if there is a way to use the shared code in a native Android project (maybe produce an AAR/JAR file).
The reason I need this functionality is because our company provides an AAR to one of our customers (that is used by a native Android project), and we would like to keep a single source base instead of two.
Thanks in advance!
Update:
The name changed to ".NET Embedding" and it is at v0.4 at the time of this update.
https://developer.xamarin.com/releases/dotnetembedding/dotnetembedding_0/dotnetembedding_0.4/
New instructions:
Installing .NET Embedding
Original post:
You can use Mono's Embeddinator-4000
It supports various language consumers, so it surfaces .NET code as idiomatic code in the target language. This is the list of supported languages at present:
Objective-C: mapping .NET to idiomatic Objective-C APIs.
Java: mapping .NET to idiomatic Java APIs.
C: mapping .NET to an object-oriented like C APIs.
Embeddinator-4000 is a tool that allows your existing .NET Code (C#, F# and others) to be consumed from other programming languages and in various different environments.
Java is currently in a preview state for macOS, Windows, and Android.
The platform is selected by passing the --platform= command-line argument to the embeddinator. Currently macOS, Windows, and Android are supported.
re: https://mono.github.io/Embeddinator-4000/
As a part of the requires For Android you will need Xamarin.Android 7.4.99+ and Android Studio 3+ (Java 1.8) but if you are building Android apps with Xamarin and Java you would have those already.
Note: This tool is in Preview, so review the open issues and post new if needed.
re: https://github.com/mono/Embeddinator-4000/issues
Note: This is not trans-compiling, but embedding Mono's runtime in a native package that allow CIL code, AOT'd (i.e. iOS) or not to run within a different language/runtime.
i was just wondering what the benefits are in using PCL with Xamarin.Forms.
I mean you share the Code between each Platform anyway.
In Xamarins native approach it is quite clear.
So maybe anybody can tell me why to use PCL in Xamarin.Forms?
PCL allows the maximum in code sharing across platforms. PCL will by it's very nature limit you to using only those API's that can be shared from platform to platform.
While you can use Shared Projects, you will find yourself using compiler directives and making coding sacrifices that can lead to bad coding practices across anything but the smallest of projects.
Using the Xamarin Forms 2.3.3 or later you can of course embed Platform Specific Controls in your Xamarin Forms pages in your PCL and they will only render when run on the platform.
In addition of maximum code sharing, it allows you to follow best practices like SOLID.
Also, please remember that there are 3 choices (not only 2):
Portable Class Library
Shared Library
.NET Standard Library
.NET Standard Library is still an ongoing work in process, so it's not there yet. But, it will be the way to go!. So, PCLs today can give you an excelent migration path to the .NET Standard Library way tomorrow.
Hope this helps.
I'm trying to understand if moonlight is a framework which is similar yet independent to the mono framework in exactly the same way as silverlight is similar yet independent for dot net framework.
I'm trying to write a library that works for both moonlight and mono and I was wondering if I would need to target specific frameworks (as is the case with silverlight and dot net).
Moonlight uses the Mono runtime but, like Silverlight, uses a subset of the available .NET framework. So yes, you'll need to target different frameworks for desktop vs Moonlight (Moonlight uses the 2.1 profile, same as Silverlight).
I have a few years of experience writing Unix command line tools (no GUI experience) in python, C and C++, and only recently crossed into the GUI world (Cocoa and IOS only). I've learned quite a bit of objective-C and am getting to understand how cocoa MVC works. However, one of the apps I am developing needs a Windows version and I was wondering what a good place to start would be given that I have absolutely no Windows development experience.
I was thinking about using Visual C++ 2010 Express as my development platform (because it's free and because I don't need to learn C++). My application is relatively simple, it will have only two windows and spend most of the time running in the background. It will however need to communicate with the OS (load dll's etc) and an online server (HTTP methods) and I'm not sure whether Visual C++ Express edition gives me access to the required API's. Would a Windows Forms application suffice? Am I going about this the wrong way? Do I need to learn C#? Any advice will be appreciated.
If you are already happy with proper c++, visual Studio C++ express should suit you fine. Given that you are not making a complicated GUI, you don't even need to dip into the managed code - C++ express allows you to create proper c++ console and GUI apps. You also don't need to install the platform SDK - it is part of VS C++ express.
Not being managed C++, you will be able to share source files between your various projects. managed c++, despite the c++ in the name, really is a different enough language that it will be annoying to work with if you simultaneously have to deal with iso C++.
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Note: The native windows API is a C api, not a C++ framework. So it does not provide a rich set of classes in a coherent framework to deal with. On the other hand, while, large, it is actually quite simple to work with.
Also: Given that you are already familiar with Mac development, there is a LGPL (iirc) package called CFLite that builds on windows and that implements the C api that underlays the Objective-C Cocoa API.
If you use its abstratcions you can share a greater part of code between windows and Mac (and other platforms).
Other C++ IDE's you might want to consider:
Code::Blocks
QT Creator
both of which can be configured to use the MINGW port of GCC to windows.
you'll be better off with c++ than c# if you need more "low-level" stuff. Loading dlls (that is, libs) is simple (pragma comment lib...), as is pure HTTP transfer and communication.
So, VC++ with windows form will suffice, and it is "very c++".
You have access to all global APIs, and loading specific apis like http requires only two lines: one to include wininet header, and other lib (libs are actually "references" to dlls).
If you go the C++ Express way then you need to install Windows SDK separately, and set it up for Visual Studio to use it. And you can't use MFC.
I would however, suggest C#, because it feels like putting little toy bricks together. Easier to debug and maintain. Problem with C# is that it has so many library functions that you can not possibly know if what you want is already made to a function. But that's why we are here :-) If you feel that something you want to do should already exist then ask a question about it. One notable feature that C# lacks is zip archives (it has something similar, but not quite). For zips you can use public libraries, like SharpZipLib or DotNetZip.
If I were you, I wouldn't jump into a whole new API so quickly. Have you considered using Python on Windows? Most of the Python packages I've seen are also available for Windows, so you'll feel at home. And if you need some GUI, you can opt for wxPython, pyGTK or something similar.
For Windows specific things, you can always use ctypes. Especially if they're as simple as loading a DLL.
have you considered approaching Adobe AIR? it allows you to deploy on Mac, Linux, Windows, iOS, etc. communicating with and launching native processes has been possible since 2.0 and the the latest 2.5 SDK can target Android OS and TVs. with your experience you should be able to pick up ActionScript3 / MXML in no time.
additionally, there are a handful of free IDEs you can use with the Flex and AIR SDKs. or, if you're a student or low-income developer, you can get a free copy of Flash Builder 4 from Adobe: http://www.adobe.com/devnet-archive/flex/free/
edit: i believe deploying AIR applications on iPhone requires Flash Professional CS5, which includes the packager for iPhone options. at the same time, i've read that AIR and other cross-compilers for iOS are painfully slow, so it's perhaps best to develop natively in Objective-C for iOS.
I'm tasked with "porting" a few apps from a Windows environment to various mobile platforms and Mac as well.
I plan on writing MVC patterned apps in which I write as many controllers as I can in some sort of universal library, probably in C or C++. Then writing the views in various choice languages (Objective C, Java, .NET, whatever) for the target OSes.
I've never attempted anything like this before, so my questions are: Is it possible to write and compile one library that can be used on iPhone, Android, Blackberry, Windows and Mac? Is it even wise to try this?
I understand that certain native methods simply won't be available on each platform.
You can create a library whose source code is portable, assuming that you properly abstract away any platform-dependent calls. You can't, however, create such a library, compile it, then use it anywhere; you'll have to compile it for each platform.
Your should take a look at the Mono Project. http://www.mono-project.com
...more specifically at :
MonoTouch: To develop iPhone applications in .NET
MonoDroid (BETA): To develop Android applications in .NET
Mono plugin for MeeGo: To develop MeeGo applications in .NET
And you know that you can develop on Windows Mobile in .NET already.
I've haven't found anything related to BlackBerry yet.
There are services like Rhomobile and Appcelerator which will allow you to do this sort of cross compiling.
I've never used either however.