Curious to know if I can use System.Xml.Linq from a C++/CX metro app. A Metro C# app can simply reference the System.Xml.Linq.dll (which it seems to do by default), but a C++/CX app requires a WinMD file as I recall, and I cannot find such a beast for System.Xml.Linq.
Thanks in advance.
No, you cannot use System.Xml.Linq (or anything from the System namespace) in a C++/CX metro app. C++/CX is a wholly native projection of WinRT and so does not have access to anything in the managed world.
A group at Microsoft is working on LINQ/Reactive Extensions for native code, though: http://channel9.msdn.com/Shows/C9-GoingNative/GoingNative-9-LINQ-for-C-Native-Rx-RxC-Meet-Aaron-Lahman
Related
So I am currently using Xamarin for multi-platform mobile applications. I really like the way this works, and I want to improve my flow. My developers have said that they would be much faster when programming natively (i.e. Swift for iOS in XCode).
I have looked for a solution, where I can create a shared project and use it in native apps, but I have only found ways that involve programming in one language for all platforms.
Is there a way to create a shared project, which can be imported into a native application (or better, can be run together, like a shared project in Xamarin)?
The language for the shared code is not important, as long as it isn't slow.
My developers have said that they would be much faster when programming natively (i.e. Swift for iOS in XCode)
Swift can be used natively for iOS apps. RemObjects' Silver is supposed to make Swift ready for Android and .NET. I've never tested it. Try it out, it's free.
RoboVM can be used to write iOS apps in Java. I didn't try it out either.
Language mixing with Xamarin
In case you want to mix Swift code with C# code using Xamarin then you can bind Objective-C compatible Swift code and use it in iOS projects only. You are not able to execute Swift code on Android or Windows Phone! It's not possible to write platform independent business logic in Swift and and use it in a shared library or PCL with Xamarin.
You face the same restrictions for Java code on Android: You can bind JARs and use them in a Xamarin.Android project but you cannot use them on iOS or Windows Phone.
You are also unable to execute C# code in a Swift based app on iOS or in a Java based app on Android.
You can use native code in Xamarin apps via Binding Libraries. You cannot use Xamarin libraries in native apps.
If the goal is to use truly native tooling, in their standard languages (meaning not Xamarin) and still share code between iOS and Android, this can be achieved by writing your non-UI code in C++.
Here's a very interesting article about how Dropbox does exactly this.
C++ is natively supported on iOS and it is very easy to interface
between Objective-C and C++ using Objective-C++.
On Android, calling into C++ can be done through the NDK, which
reportedly is not a pleasure to use. Dropbox found Google’s meta-build
system gyp to work reasonably well. In addition, the Java Native
Interface is a pain you have to accept. But none of these issues is a
roadblock, and Steven expressed hope that Google or the community will
build better tooling support over time.
And here's a simple example of how to do this from another StackOverflow post
We have an line-of-business app that runs on Windows Mobile. It's a Winforms app with a local SQL CE database and gets its data from a WCF Web Service running on the server.
Now customers are always asking "why don't you make a version for iPhone/iPad/Android/Phone 7 etc". My boss asked how hard this would be. My initial answer is very hard especially since I would probably be the only person doing the work. I don't have any experience outside my Visual Studio happy place.
Now I've come across MonoTouch and MonoDroid. They appears to offer an easy solution but I'm sure there are lots of issues. I doubt that I will be able to just compile my app for Android.
I'm inclined to suggest that it would be far too much work and that the only realistic solution is a mobile web site with several versions of each page for different screen resolutions. Unfortunately the existing app has a local database and is "sometimes connected" so that won't cut it.
Any suggestions and tips before I waste a huge amount of time?
Cheers
Mark
I doubt that I will be able to just compile my app for Android
That is correct; you won't.
So, background: the design philosophy of MonoTouch and Mono for Android is to bring the "core" .NET and C# experience to iOS and Android while also exposing the underlying features of each specific platform. Whereas PhoneGap and Titanium abstract the underlying platform (for a "write-once, run-anywhere" vibe), MonoTouch and Mono for Android provide no platform abstractions and directly expose the underlying platform types and members.
The result is that MonoTouch programs use MonoTouch.UIKit.UIButton, which directly wraps the underlying CocoaTouch UIButton type.
Similarly, Mono for Android programs would use Android.App.Activity, which directly wraps the underlying Android android.app.Activity type.
Common across both platforms are the "core" framework namespaces and types which you find on .NET, .NET CF, Silverlight, Windows Phone 7, and Mono: System, System.Collections.Generic, System.Linq (yes, Linq-to-Objects), System.Xml.Linq (yes, Linq-to-XML), System.IO, etc., etc. For example, see the assemblies included in Mono for Android.
So, can you use your existing Windows Mobile app as-is on Android? No, because Mono for Android doesn't provide System.Windows.Forms.
However, it should be possible for you to refactor your existing code to follow a Model/View/Controller design pattern (or MVVM, or...), abstracting away the UI (View) so that you can replace it for various platforms, e.g. an iOS UI with MonoTouch, a WP7 UI with XAML, an Android UI with Mono for Android, an HTML UI with ASP.NET MVC, etc., etc. You won't get a "write once, run anywhere" experience, but you will be able to provide the user with native user interfaces which are consistent with their chosen platform.
For example, see the MIX11 Conference Apps, which utilize a common code base while providing platform-specific UIs for iOS, Android, and WP7.
look at titanium and phonegap.
My suggestion is to have a quick look at WP7. It's quite easy to jump in to, even more so if you have Visual Studio (which you do) and C# experience of any sorts. Then you should be able to more easily guesstimate how long it would take you to develop a C# application (and possibly port that to Android using MonoDroid).
And yes, Titanium & PhoneGap are options, but I personally think MonoDroid looks better.
What platform are you getting the most requests for? I am guessing Android, as that seems the most likely. I have seen a lot of people saying MonoDroid is really solid.
Is there a sane way to develop a cross platform Mobile app? We want these to be native apps on each platform, and not necessarily some kind of web page.
Currently we're thinking to split it into two languages:
C# backend (business logic)
--> Standard C# app for WP7
--> App built on MonoTouch for iPhone/iPad/etc.
Java backend (business logic)
--> Standard Android Java app (MonoDroid version of C# not ready
yet)
--> Standard Blackberry Java app
We could also develop initially in C# and use one of the conversion tools out there to get our C# converted into Java as a starting point.
Is there another approach? Our skillsets include mainly include a strong C# .Net background, and minor Java experience.
We don't really want to go low level and use something like C/C++ to get the job done. These are usually going to be simple LOB applications that communicate to some web service.
Side Question: how do game devs like the makers of Angry Birds do it?
UPDATE:
MonoDroid is now officially released. So it seems you would only need to use Java for the BlackBerry. We are considering not developing for BlackBerry at all, because developing for the other 3 platforms has been simplified. There is definitely some cost involved, as MonoTouch and MonoDroid are both $399 and you would also need a license for Visual Studio (this doesn't include cost for App store, etc.).
There's no good simple answer that I know of for all mobile platforms. You can use development environments like Appcelerator Titanium, which cross-compile to native code on various platforms (right now, for instance, I think Titanium supports iOS and Android, with plans for Blackberry). However, these usually have a limited API that you have access to, and you still end up needing to design different UIs for the different platforms (in my commercial work, I have never successfully used such a platform)
You could also design all the business logic in a web-services back end, and then just write "thin client" apps for each platform. This works, but of course requires network access when the end user wants to use your app. (Usually it'll be there, but sometimes may not)
Ultimately, I usually end up doing what you propose -- writing the basic business logic in a couple of different languages as generically as possible, and then bundling that in with custom UI/device code for each platform. Haven't found a better way myself....
(BTW, I believe games like Angry Birds are written largely in OpenGL and then loaded onto the OpenGL processor on each platform. But I could be mistaken...)
Those are some great answers. I agree, x-platform development is still very primitive. I'd like to add 2 points:
1) You do not need to write your backend in different languages. Choose one language (based on your comfort level, performance etc. criteria) and then connect from your platform-specific apps directly to the backend. If your backend is server-side code, one way of talking to it would be via XmlHttpClient. If it's a piece of native code common across various apps and is written in say C++, you can use JNI from Java and wrapper assembly from C#.
2) Another reason for avoiding x-platform tools is that you'd always need to wait for them to support the new APIs released by the platform vendor (Apple, Google, MSFT etc.). Once these companies release new APIs, the tools will need to be updated and only then will you be able to use the new APIs.
I don't think this is (easily) possible, if you're not using some HTML5 (jquerymobile etc.) in a WebView in your own app (looks like a real app, but still you will somehow see that it's not) instead of the normal browser. You can still use some native API from the device (accelerometer,...).
There are (commercial) platforms like Sybase Unwired Platform that help you in generating some client code. Afaik for Blackberry and Windows Mobile even some UI can be generated out of the business objects on the server. But to me it sounds that this might be too heavy-weight for your case.
Regards,
Martin
develop android apps that should support iphone,ipad,android.is there any way for developing this kind of generic app or we need to develop aps depending on mobile os
Though it is possible to create an universal application for iphone and ipad i don't think you can do the same for Android.
In my opinion it is always better to port your application to Android based on your requirements so that you can take advantages of the API's that the platform is offering you.
You can try using a framework named Titanium Appcelrator. This framework will help you target iPhone, iPad, Android with the same code base. This also lets you access most of the Native hardware features available with these platforms but not all. It seems that this also may support Blackberry soon.
We are struggling with the same question at the moment. Since we are working for Android, Maemo, Meego, iPhone and Blackberry (+Symbian 3 soon), HTML5 looked promising, and we dedicated quite some time investigating it. The end result was HTML5 is not yet ready for the development we were hoping for. It's fine if you need simple functionality, but as soon as something more advanced is needed, you need to create a different version. Even if it suits your needs, every platform requires different HTML5-to-native bridge, and every platform has a different engine. As you can see, only front end part could be partially used.
In your case, you need two different applications, one for Android, another one for iPhone/iPad. Try to see if you could take advantage of HTML5, if not, you are unfortunately stuck with separate development for some time to come. Unless you will create a web app and use it with device's browser.
You can create common functionality libraries with C or C++ and use these libraries in iPhone/iPad and use Android's NDK tool to integrate theses libraries with Android
On Android, you're using Java as the main language, and you can also use C and C++ . On iOS, you're using Objective-C as the main language, and also can use C and C++. So the common denominator would be C (at least on the iPhone there are no C++ GUI classes). I have no idea about developing on Android, but on iPhone it's no fun to purely work in C (and I'm not sure if it's even possible, maybe it is but should I when working with Objective-C/Cocoa is fun).
What you can do is write generic logic and share that between both systems, like a library. For example, I worked on a project where we used a C++ SIP/VoIP library that also compiles and runs on Symbian. It shouldn't be a big problem to write C code that can be shared between iOS and Android, as long as it is mostly about logic and not about calling system-specific stuff (you can of course include system specific stuff and guard that with #ifdef but you don't want your library to have more system-specific than system-agnostic code, I guess). For example, if you intend to write a networked game you could implement the network protocol in a way that could be shared between iOS and Android.
But as soon as you're hitting the GUI level I don't think you can share any code, and even if you could you probably don't want to because if you use the native languages/IDEs you are faster designing the GUIs each in their respective main languages/IDEs than trying to find a common way and then have to live with compromises and trying to make it work on both systems all day long. Better to implement the GUI native to each platform (e.g. Xcode has a very good graphical tool called Interface Builder that can save a lot of work/typing).
we can go for the XML VM to run the android apps in iphone.
Check this for more info.
xmlvm.org
I've got an iphone app and I'm looking to port some of the data-layer objective-c code to a scripting language which can also run on an android phone.
Any suggestions on what to use? I'd also like to be able to push new scripts to the app for bug fixes. Not sure if this is against the iphone SDK agreement or not.
JavaScript. Anything else is explicitly banned by the Apple Store Vetting process.
(You could actually serialize some Objective C objects and take advantage of some of the dynamism in the language, but that won't get you far with Android. So, JavaScript.)
As far as I know, iPhone SDK agreement forbids using any scripting languages in your apps.
On the other hand, JavaScript runs both on Android and iPhone (and a couple of other platforms) and is a very powerful language.
The only scripting language that Apple allows for use with downloaded scripts is Javascript.
You can execute the Javascript code inside a visible or invisible UIWebView.
If you write a domain specific language in XML and parse it that way, you could do what you want.
Both platforms can easily parse XML.