Develop Reference

Is it possible to compile a Xamarin project as a library for iOS and Android?

I need to create an API library for Android and iOS. I have experience working with Android projects, but zero experties in iOS. I was wondering if I could create a Project library in Xamarin that compiles as a JAR for Android and as an... I-don't-know-which-type for iOS.

No, that isn't possible. Depending on what you are trying to accomplish there may be alternatives. If you are trying to make a library that can be used by others you could make it a Xamarin component - there is a component store you could put it on if you want it to be generally available, otherwise you can use any normal means of source or object distribution.
If you need to interact with a native app/library then you could make the C# code the "owner" of it and have it call into the native code. This works for both IOs and Android (and is used to work with e.g the play services from google).

No, it is unfortunately not possible to do that.

It seems to me that what you need is a Portable Class Library also known as PCL. It allows you to create a project which can be referenced by all Xamarin supported platforms (such as iOs and Android). There are obviously limitations to the approach like not being able to reference platform specific libraries but in your case (of writing an API) it should suffice.
You can read more in this link
Good Luck!

AR.Drone development for Android

I knows that the AR.Drone is controllable for Android phone.
However I can't found any open java source code for me to develop!!
All I have found is the code with the type .h which I knows only for
C++ (iPhone user)!
Can any body give me some idea to develop AR.Drone with java code on eclipse?
thx
:)

there is javadrone ( http://code.google.com/p/javadrone/ )
Note: this lib has issues with the AR.Drone 2.0 - fixed ( for at least flying ) here: https://github.com/xperimental/moder.AR.drone/blob/master/library_projects/javadrone-api/src/com/codeminders/ardrone/ARDrone.java

The AR Drone application programing interface API can be found here:
https://projects.ardrone.org/
The API is in c++, if you intend to develop for iphone you will have to write an application from the ground up because the application that exists on the iphon currently is commercial. (Closed source).
As is the android one because they are developed by parrot.
I developed for the ar drone using the computer which was much easier, depending on what you are trying to do i would develop on the computer. If you need more help i would suggest asking here:
http://www.ardrone-flyers.com/
Good luck

We used yaDrone for an autonomous drone project - the library was very reliable.
Furthermore there is an eclipse tutorial for yaDrone.

If you need to build an IOS app you can use openFramework and ofxARDRone from Memo Akten to control and get the video. This framework is written in C++. You can use this framework in XCode and build for IOS, too.

Can I use Lazarus Pascal to build for iOS AND Android

I would like to know:
If it's possible to use Lazarus (Pascal) for both Android and iOS development.
If the answer seems positive, do I need a third-party SDK/API or package to do this?
Thanks!

Android: See answer from Nic Strong.
iOS (iPhone/iPad): Check google and find this result.

I am almost certain the answer is no.
EDIT: Looks like I was wrong. See http://wiki.lazarus.freepascal.org/Android_Programming

The answer is yes. For Ios Lazurs uses objectivepascal which a pascal extension that allows integration with objective-c much like objective-c++.
However it is necessary to do some work to set-up the environment and you need an Apple computer to build test and debug.
This is the best entry point for iOS development:
http://objectivepascal.com/

Start programming to Android

I know there is a dedicated area for Android issues, BUT I just want to know if there's an option to program to Android in C or in Java, and what will be the best language to write apps for Android.
This info you can't find in the Android area...
Thanks !!

Android practically is java.
Just read some how to start tutorials and you will see theres not much difference to conventional java applications.
It is Java with some platform dependent features.
SDK:
http://developer.android.com/sdk/index.html
DevGuides:
http://developer.android.com/guide/index.html

The Android API is in Java. You can find the developer guide here.
For performance-critical code, you can use the Android NDK.

Android's comprehensive java SDK makes it a lot easier to write apps in Java. You should check out the getting started page on their developer site.

The best? Java.
You can also write in C/C++ with the NDK.
And you can also write with Python or, say, Scala, but is not easy at all.
Java is the best because the API is Java, so all the documentation is in Java. Equally important, Google's ADT plugin to program Android in Eclipse is super easy, so you are going to work with an IDE, no need to advanced text editors and so.

Android applications are java based. (although I heard new NDK support development of full application in C).
It is possible to develop some libraries in c/c++ and load them to your application using JNI, which is also a Java feature. Start from here: http://developer.android.com/index.html I know it seems to general, but the official site is a great place to start from.

You use Java to program Android. It says it in the documentation for development for Android.
You can also use the NDK but don't start with that.

Traceroute on android

I am a beginner on android platform, and I want to build a tracerouting app. So these are my queries:
Is it possible to make such an application in Android? if possible then guide me the way that I follow.
Does Android support low-level programming to capture ICMP packets? or do I need to add some kind of JAR (in java) or some other libraries to support this application?
In Java, there are JPCAP and docjar etc kind of libraries that we can import in our IDE or Eclipse so that Java support for making such kind of API's?
I need valuable suggestions.

It's quite late - but someone might see it.
i found this one and it worked for me:
https://github.com/olivierg13/TraceroutePing

The simplest way I can think of is to just check for the traceroute Linux application, execute it, and parse its output.
Android has full networking support, however, Java doesn't expose an interface to alter the IP header. Hence, manually crafting ICMP packages is out of the question (JPCAP is no help here, since it relies on libpcap, which I suppose you won't find on any vanilla installation).
Another possible solution is to use the NDK and create a small library that handles the low-level number crunching. However, I'm not sure if the NDK would allow you to use setsockopt.

This is working pretty well for me, you may have to filter out the string results.
To add this library, you have to download or clone the git repository and implement the folder "library" just as he does in the other module "app" for it to work properly.