tendulkar-uvāca : Episode 2

In previous episode of tendulkar-uvāca, we’ve seen how we can setup our development environment using Visual Studio and Xamarin.
In this episode, we’re going to see how we can use emulators to test and debug our applications.

iOS simulators will get installed with XCode is installed.
For Android emulator, install Xamarin Android Player from here
Windows Phone emulators can be installed while installing Visual Studio 2013 Update 3.

Do let me know your feedback and suggestions.

Mayur Tendulkar

Plugin 05: Accelerometer

In our series on plugins, today we’re going to cover plugin which can help us to work with Accelerometer sensor. This sensor is responsible to detect X, Y, Z co-ordinates of the devices. Using data received from this sensor, you can build games like TempleRun, where users can collect the coins by tilting the device.

There are different APIs for different platform and their usage is different too. First, lets see how we can use this sensor in different platform and then we’ll use plugin in Xamarin.Forms application.

Being Windows Runtime API, the API and its usage is same in Windows and Windows Phone. Here, you create object of the sensor and register for ‘ReadingChanged’ event. Whenever device position is changed, it is reported through that event and UI can be updated using Dispatcher.

In case of Android, it is again similar to Windows platform. Create object of SensorManager and register for SensorChanged event.

iOS is not any different. You create object of CMMotionManager and then listen to sensor for changes.

As you can see, for three different platforms the APIs are totally different. But with Plugins for Xamarin.Forms it becomes easy. You can use DeviceMotion plugin which can work across all these platforms. And the code for same looks like:

In this series on plugin we’ve seen how particular concept can be implemented in all the three platforms and how we can use plugin to make life easier. This will be be last post in this series, but there are many plugins available which you can explore and use in your projects. Do let me know if you want to cover any specific plugin. We’ll start with a new series in couple of weeks. Till then… happy coding :)

Mayur Tendulkar

Plugin 04: FileIO

In continuation to blog posts in this series on plugins, today we’ll cover a plugin/library to perform FileIO.

There are different APIs on different platforms to perform FileIO. Having said that, Xamarin already makes life easier by implementing System.IO which is available in Android and iOS.

Following code can be used in Android to create a file and then read contents from it.FileIO - Android

Similarly, following code can be used in case of iOS application. FileIO - iOS

In case of Windows, using WinRT APIs, the case is little bit different as shown below:FileIO - Windows

Now to make life easier, there is a NuGet from Daniel Plaisted, which can help you to use same code on different platforms. You can find more information about the library from here: https://www.nuget.org/packages/PCLStorage/FileIO - Forms

This way, you can use one code (in C#) across all the three different platforms.

Hope you’re enjoying this series. Do let me know your feedback if you want to include any specific libraries/features.

Mayur Tendulkar

Plugin 03: Phone Calling

In continuation to blog posts in this series on plugins, today we’ll cover a plugin to make phone calls.

As we understood before, all platforms support phone calling (just like emailing, texting, etc…) and Xamarin makes it easier with one common language – C#. However, developers still need to learn

In case of Windows Phone, one can initiate a phone call by using following code. In this case, Windows Phone has special class which allow developers to perform this task.

Screenshot 2015-02-23 10.53.12

In case of Android, developers can use ‘Intent’ and ‘URI activation’ to start a new phone call.

Screenshot 2015-02-23 10.56.09

In case of iOS, same concept of URI activation can be applied. As shown below in the code, developers can create a URI with telephone number and it will launch default application to make a phone call.

Screenshot 2015-02-23 11.13.09

Now, in case of Xamarin.Forms developers can use same Messaging Plugin for Xamarin and Windows plugin to implement phone functionality across the platforms.

Screenshot 2015-02-23 12.31.23

This way, developers can utilize the power of plugins to write one code which can work across different platforms, without bothering about underlying APIs.

Mayur Tendulkar

Don’t Re-Invent the Wheel: Use Components or Plugins In Your Apps

Xamarin provides native, cross-platform mobile application development using language we all know and love – C#. However, it is still required to learn concepts of each platform. For example to send text message (SMS) in all these three platforms there are different set of APIs.

Below API is for Android, which uses SmsManager to send the text message. There is another way to do this using Intents.


In case of Windows Phone, ChatMessage allows us to declare and send text message. This API is available in WinRT platform. In case of SL based apps, we need to use Launchers/Choosers.


In case of iOS as shown below, there is no API as such. But we use URL to launch default messaging app. In this case, we cannot set the message body, which we want to send out.


Life will be much simpler if there will be just one API on all these platforms which will take care of sending text messages and as I developer we don’t need to bother about on which platform it is being called. Here comes components and plugins. My friend James has written a nice blog about ‘What Exactly is a Plugin for Xamarin?’. You can read it here

In our case, we’re going to use Messaging Plugin for Xamarin and Windows which allow us to use same API to send text messages. Below code is written once in a Xamarin.Forms project which depending on platform on which code is executing, send the message using that platform’s APIs.


Using this plugin, it becomes easier to send text messages on Android, iOS and Windows. And this is the magic of Plugins for Xamarin.

In future posts, we’ll cover some of the best plugins and components which can help you build cross-platform mobile applications with single code-base.

I hope you’ve enjoyed this.

Mayur Tendulkar

Revisiting Evolve – Insights

One of the factor for successful app is – continuous feedback from user. Even though, you anticipate all the possible bugs, once the app is on store, you’ll never know what can go wrong and when your app can crash on the user. You may want to know: how many users are using your app, when they are using, how they are using, what features they are using or if the app crashes, when, why and how it crashed. These analytics can help you to engage more with the audience and deliver great apps.
Thanks to Xamarin Insights, which was introduced in Evolve 2014. Using Insights, you can easily track down all these scenarios.
To get started visit https://insights.xamarin.com/ and create a new app.



Insights is supported on Android, iOS and Windows/Phone apps. Using NuGet package, add Xamarin.Insights NuGet Package.



Once you add this package, you need to initialise the Xamarin.Insights by using following code:


Just remember, you need to initialise Insights before any exception can occur. For example, in case of iOS in Main, in case of Android in OnCreate of startup activity and in case of Windows in Launch event.
After this, whenever there will be any unhandled exception, it will be reported on the dashboard. To simulate this behaviour, lets add a button on screen and catch the exception and report it explicitly.


As you can see, above code will raise IndexOutOfRangeException. Now, if you run the app in ‘release’ mode on ‘device’, it should show all these exceptions on Dashboard.


Now, if you click on individual exception, you can see more details (incl. stack-trace) for that exception. This will also tell you more details about device on which app is running, the version of the device OS and other details.



On this dashboard, you can go to Users tab and see individual user actions and how they received those exceptions.



Insights give you APIs to report more details related to Users (individual user details like name, email id, etc…), their actions or traits (clicked on some button, navigated to some tabs, etc…) and also to add more details to exceptions. It can also send you email for individual issues. So, if there is any issue with high-priority, you’ll receive a notification mail and get notified about it. Insights, also allows you to integrate with HipChat, Jira, Visual Studio Online to get notified about issues.
Using Insights, you can easily engage more with your audience. If user is facing any issues, you can get notified about those issues. And once you solve those issues, you can contact user about updates. This will help your users to use your app more frequently while making it a successful app.
You can find more details about Insights at: https://insights.xamarin.com/docs or http://xamarin.com/insights
Hope to see more apps with Insights and user engagement.

Mayur Tendulkar

Cross-Platform. Hybrid or Native?

Recently I had to build an app for our company (zevenseas) which can work across all the platforms i.e. Windows Phone, Windows 8, iOS (iPhone, iPad) and Android (Phone and Tablet). I started looking for various options like Titanium, Icenium, PhoneGap & Xamarin. Considering the options I had, I chose two best solutions Icenium and Xamarin. But like many, I was confused about which one to use & when, one being hybrid and other native. So, I used and tested both and here are my findings in this post.

Experimenting with Xamarin – A native solution

I started using Xamarin (build on top of Mono) since February 2013 and I’m loving it. Just think about writing apps for Android/iOS/Mac using the language that you’re using since years – C#. The best feature that I can see which Xamarin provides is one solution to build them all. Just think about having one solution, which has all the required projects & dependencies at one place. Everything in one IDE (Visual Studio), one solution and in one repository, built using one language. This is AWESOME. The other most important feature for me is Portable Class Libraries (PCL). Think about having your Data Access Layer, Business Logic Layer, Models, etc.… into PCL and then referring it into various different applications. Just create UI layers. 100% code re-use. Isn’t it? So, think about project structure like this:


Other awesome feature which I liked about Xamarin is, their releases aligned with release of .NET features, iOS and Android. You can use LINQ, Async/Await, PCL in your cross-platform project. One more thing to mention here, Xamarin provided support for iOS7 as soon as it got released. Pretty amazing.

The challenges with Xamarin

I can see some challenges with Xamarin & yes, those can be addressed. First one is third-party SDKs equivalents and controls. Recently Xamarin is coming up with their components-store and I’m waiting for few SDKs and components to appear in it. Perhaps, this can be a great opportunity for some folks to build and sell their components/controls. For example, I wanted to build mobile app to fetch data from SharePoint. For Windows Phone, there is SharePoint SDK for Windows Phone. Being lazy, I wanted that same SDK as Xamarin component. It is doable. No doubt. But if somebody can provide it to me, or provide solution to migrate these kind of SDKs to Xamarin I’ll be happy. (btw, Xamarin has something called scan my code which analyses the code and tells you how much of it can be reused across platforms).


In case of controls (like Telerik, Infragistics, ComponentOne, Mindscape and Syncfusion), it would be great if I can port/use existing controls (without reinventing the wheel) written in .NET; in my cross-platform solution. I know, it is going to take time, but still.

Second challenge that I found is if I want to build highly touch intensive app like which includes drawing/animations/etc…. manipulating that in C# can be difficult. Same can be achieved with existing JavaScript libraries in Icenium. Although there is MonoGame for game development, works just like Xamarin products and built on top of Mono.

Playing around Icenium – A hybrid solution

I have fair understanding of JavaScript/JQuery and have used JQuery Mobile to build mobile web-apps. So, getting used to Icenium was damn easy. The great thing I loved about Icenium is, I can use same code (UI, DAL, BAL, etc…) for all the platforms. Plus, I can run any simulator and test the app LIVE. When I say live means, just make a change in HTML/CSS/JS, save and the it affects the app in simulator. Too good. Plus these simulators are pretty fast. In case of Android emulator, if I start it, I can easily go for a walk, have a cup of tea and still emulator is booting-up on my machine. I’ve ‘one of the best machine’ – thanks to zevenseas.  (P.S. Xamarin has nothing to do with Android emulator. It uses Android’s native emulator i.e. AVD etc.…, which by default slow. You can try Intel HAXM & Intel Atom based Android images in this case)


Being hybrid app platform, I can use all existing JavaScript libraries including Jquery mobile, Kendo UI or what not. The list is endless. This is LEGEN—wait for it DARY… The challenge with Xamarin (third-party libraries) can be solved here. Other feature which I liked the most is, you can build the app and run or test it on Android or iOS device without developer account. It uses something called Icenium Ion. Because *i think* provisioning profiles is pathetic with Apple. Microsoft and Google are way better in this case. However, remember that at the end you need developer account to publish the app. You can delay this, but can’t skip.


The challenges with Icenium

I found some challenges when dealing with Icenium. First, if you already have your existing logic in C# (in case of Xamarin, PCL is the best solution), then porting it to hybrid app (JS) can be time consuming affair. You may need to re-write. But this re-write can help you to use that code across platforms. Second, the simulators are not active simulators and has some limitations. Which means, you can’t use hardware buttons like back/home/menu etc… on Android/iOS. Keyboard inputs work from real keyboard connected to development machine. You also can’t test most of the Cardova plug-ins.

Apart from these challenges, I found both Icenium and Xamarin good options to build cross-platform solutions. So, the question is when to use what?

  Icenium Xamarin
Use existing C# Knowledge and code
Incl. Async/Await, LINQ, PCL, etc…
Use existing JS knowledge and code
Inc. Jquery, JQMobile, KendoUI, etc…
(Windows Phone/8, Android/iOS/Mac/Desktop/XBOX)
Android & iOS

Edit: I just found that Icenium as IDE allows you to build apps for Android, iOS. However, the same code can be used to build for Blackberry and Windows Phone externally i.e. like using Visual Studio to build XAP (Windows Phone package). Using respective build process. Thanks to Lohith for pointing out my mistake.

When it comes to documentation and support, both of these solutions are good. Xamarin uses default .NET APIs which you already know. In case if you’re looking for platform specific API, while going through Xamarin docs, you can navigate to Apple or Android documentation. Basically, Xamarin has one-to-one API mappings/bindings (just for example, it may be different. I don’t know internals). So, it makes life easier. Icenium on the other hand, is all JavaScript. You may need to check with each JS library vendor for documentation. Support is good as both the solutions have active forums and twitter handles to ask questions.

I will not talk about performance. I haven’t built similar kind of application using these two solutions to check performance. Hence, I can’t comment on this point.

So far I’m loving both of these solutions to build cross-platform applications and I’ve my own reasons to choose right-one at right-time. Do you? Do let me know if you need any further information.


Mayur Tendulkar