Xamarin.Forms Projects – Second Edition

The second edition of Xamarin.Forms Projects is now published. You can buy it from Packt or Amazon. It will also be available in other book stores. More Information An example-driven guide to help you build native cross-platform mobile apps using Xamarin, .NET Core 3, and Visual Studio 2019. Set up Xamarin.Forms for building native apps […]

  6/20/2020 - 10:12 AM

App In The Cloud – Build an app powered by Custom Vision in Azure Cognitive Services

In this episode, Daniel Hindrikes shows how to use a model that is trained by Custom Vision in Azure Cognitive Services in an app built with Xamarin.

  4/6/2020 - 12:10 PM

Introducing TinySvgHelper

For a pretty long time I have had code that I have used for a couple of different apps that uses SkiaSharp to convert an svg image to a Xamarin.Forms ImageSource. I also blogged about it two years ago, https://danielhindrikes.se/index.php/2018/03/13/use-skiasharp-to-convert-svg-to-xamarin-forms-imagesource/. But I never released it as a library until now. Get started with TinySvgHelper The […]

  3/31/2020 - 9:42 AM

Android Image Classification with TensorFlow Lite & Azure Custom Vision Service

Read my blog post about Android Image Classification with TensorFlow Lite & Azure Custom Vision Service on the official Xamarin blog, https://devblogs.microsoft.com/xamarin/image-classification-xamarin-android/

  3/30/2020 - 9:28 AM

App In The Cloud: Native mobile, desktop and WebAssembly apps with C# and XAML using the Uno Platform with Jérôme Laban

With Uno, you can build native apps and Web Assembly apps with C# and XAML using WinRT (UWP) APIs. In this episode, Daniel is talking with Jérôme Laban, the CTO of Uno Platform about what Uno is, the history of Uno, the current state of Uno and much more. Jérôme Laban on LinkedIn: https://www.linkedin.com/in/jeromelaban/ Jérôme […]

  9/26/2019 - 10:43 AM

App In The Cloud – Live Code – Episode 2, Azure DevOps

In episode 2, Daniel show hot to set up Azure DevOps pipelines for a Xamarin app. Here is the recording from the stream:

  8/26/2019 - 11:51 AM

App In The Cloud – Live Code – Episode 1

Together with my friends and colleagues, Johan Karlsson and Mats Törnberg, we have started to live code on Twitch, https://www.twitch.tv/danielhindrikes. Right now we have started to build a Xamarin.Forms app from scratch, the plan is to continue to build that app, live on Twitch every Monday at 12:00 CET (Swedish time). If you missed it, […]

  8/20/2019 - 6:54 AM

App In The Cloud: Weird stories from 10 years as a mobile developer with Christopher MANUE

Christopher MANUE has worked as a mobile developer for over 10 years, he has for example worked with the MSN and Deezer apps. In this episode, he shares some of his experience and tells us some weird stories from developing high scale apps.

  6/25/2019 - 8:24 AM

The Code Behind: AR for dummies

In the book Xamarin.Forms Project by me and Johan Karlsson there is a chapter about how to build an AR app using ARKit, ARCore and UrhoSharp. In the podcast, The Code Behind, (in Swedish) that we are recording we speak about that topic. So if you don’t speak Swedish, this is a great chance to […]

  1/22/2019 - 6:38 PM

Xamarin.Android maps – adding high-resolution map images

Recently I started to build a map-based app where I wanted to show a map with map images as an overlay. For example, if I have an image for a specific area I want to show it on the map in the app. The way to do that is to use GroundOverlayOptions. and just use […]

  8/21/2018 - 1:20 PM

Using Machine Learning and Azure Custom Vision for image classification in your apps

Last fall, me, my family and a friends family took a trip to the forest for collection mushrooms. This blog post will not be about the trip to the forest, but that my friend not was good to recognize mushroom species I got an idea to write an app for that. So this post will be […]

  7/5/2018 - 12:12 PM

VSTS and Android NDK

If you want to use AOT-compiling (AOT = Ahead of Time) for your Xamarin.Android it requires that Android NDK (Native Development Kit) is installed on the machine that will build your app. I using VSTS to build my apps and I using the “Hosted VS2017” build agent. After I enabled AOT and LLVM (Low Level […]

  6/12/2018 - 10:44 PM

Store user data in an secure way

In many apps you want to store user data locally on the device, it could, for example, be passwords, credit card numbers etc. Even if the storage is sandboxed to your apps, you don’t want to store it in clear text, you want to store it encrypted. I have used Xamarin.Auth for many apps while […]

  12/8/2017 - 2:19 PM

Add custom tiles to map in Xamarin Forms

If we want to use other maps than the platforms default in our apps we need to provide tiles to the map view. To do that we need to create a custom renderer per platform. iOS In iOS we need to create an url template that contains {x}, {y} and {z}. Those be replaced with […]

  7/5/2016 - 12:40 PM

How to solve Xamarin.Forms android build error after updated to Forms 2.0+

Exception while loading assemblies: System.IO.FileNotFoundException: Could not load assembly ‘Microsoft.Windows.Design.Extensibility, Version=4.3.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’. Perhaps it doesn’t exist in the Mono for Android profile? If you updated the nuget packages for Xamarin Forms to 2.0+ and the android project stops to build there are a simple solution. Just delete the references which ends with .Design. In […]

  2/1/2016 - 10:41 AM

Xamarin.Forms and large images in android apps

Are you getting out of memory exception when your running your Android app? It’s common that the reason is that a large image is loaded. If it’s the case, take a look at this article at the Xamarin developer portal, http://developer.android.com/training/displaying-bitmaps/load-bitmap.html. But how to implement it when you’re building your apps with Xamarin.Forms? In this […]

  12/2/2015 - 8:28 AM

Automatiserade UI-tester på mobila enheter

Intresserad av effektiv testning av mobila enheter? Med Xamarin TestCloud kan man köra automatiserade UI-tester på mer än 1800 fysika iOS och Android enheter. Jag har skapat en kort introduktion på ca 10 minuter.

  11/9/2015 - 2:56 PM

MvvmLight Navigation Extension

When navigating in iOS we can choose to do a modal navigation. That means that we open a page that is on top of the other pages and not included in the navigation stack. When using MvvmLight we only have one method (NavigateTo) when we want to open a new page. While I want to […]

  11/9/2015 - 11:33 AM

MvvmLight and Xamarin.Android

Last week I wrote a blog post about Xamarin.iOS and MvvmLight. Now it’s time for the second post about MvvmLight, this time about how to use it with Xamarin.Android. Because I put the ViewModels in a separate project I can use the same ViewModels for both Android and iOS. First we install the NuGet package […]

  11/3/2015 - 10:19 AM

How to succeed with Xamarin.Forms

Xamarin.Forms makes it possible to write UI for all the major mobile platforms, iOS, Android and Windows Phone with one shared code base. Many developers think that Xamarin.Forms isn’t is good enough to create apps that will be published and they think Xamarin.Forms is more a tool for prototyping. If you think Xamarin.Forms is a […]

  10/16/2015 - 1:14 PM

TechDays 2015

Den 20 oktober börjar TechDays med förkonferens, jag och Johan Karlsson kommer att dela med oss av våra kunskapar gällande cross-platformutveckling. Att bygga cross-platformlösningar är alltid en stor utmaning då det i grunden är olika operativsystem, programmeringsspråk och utvecklingsmiljöer. Xamarin löser en stor del av cross platform problematiken genom att man kan utveckla appar för […]

  6/30/2015 - 8:13 PM

Xamarin.Forms Android CardView

When Google introduced Material Design for Android they introduced a new view called CardView. Xamarin.Forms doesn’t have support for CardView by default but you can easily create your own view that renderers a CardView on Android. First step is to create a Xamarin.Forms control in your shared project. public class CardContentView : ContentView { public […]

  4/7/2015 - 7:52 AM

Preserve data when deploying Xamarin.Android app

By default all your data from your previous runs is deleted when you’re deploying an Xamarin.Android app. In many cases you don’t want the data to be deleted. Visual Studio To preserve data go to Tools -> Options -> Xamarin -> Android Settings and check “Preserve application data/cache on device between deploys”. Xamarin Studio To […]

  3/11/2015 - 3:10 PM

Building a ScreenshotManager to capture the screen with code

This blog post will show you how to build a screenshot manager to use from shared code when building apps with Xamarin for Windows Phone, Android and iOS. First of all we need to create an interface in the shared code library. In this example there will be one method in the screenshot manager. This […]

  2/26/2015 - 11:32 AM

Using Context Actions in Xamarin.Forms ListView

One of the news in Xamarin.Forms 1.3 is what Xamarin call context actions. With context actions you can make a ListView much more richer. What you can do is to add a menu to every row in the ListView. On Windows Phone and Android is the menu showing when you’re long pressing on a item, […]

  2/20/2015 - 1:10 PM

Grouping a ListView – Xamarin.Forms

In many cases when you want a list of items you want to group them in the list. To use groups in a ListView with Xamarin.Forms is very easy. Below are screenshots from Android, iOS and Windows Phone where there is no HeaderTemplate used. First step is to create a group class that inherits from […]

  2/18/2015 - 2:17 PM

Monitor an app with Xamarin Insights

I Think it’s really important to monitor apps. Of course the most important part is to log errors in the app. But I also like to track how my users uses my apps. For the lastest app I have built I have used a monitoring tool from Xamarin called Insights, http://xamarin.com/insights. While I alwas have […]

  2/13/2015 - 11:55 AM

Crossplatform and storage strategies

Many applications need to store data related to the application. If you’re building applications for multiple platforms the APIs for storage is different. Following five storage types is the most common ones: Local storage Storage to store application data locally on the device. Remote storage Storage to store application data in the cloud, for example OneDrive or […]

  1/20/2015 - 2:44 PM

Extend Label in Xamarin.Forms with a font color property

The label control in Xamarin.Forms does not have a FontColor property. But the control is easy to extend. First create a new class that inherits from Label. Create a FontColor property of type string. The value of the FontColor will in this example be an RGBA string. public class CustomLabel : Label { public static readonly […]

  9/24/2014 - 3:31 PM

Xamarin, MvvmCross and ValueConverters

This post will show you how to use ValueConverters in an Android app built with Xamarin. For an introduction to Xamarin and MvvmCross read this blog post. If you want to convert values before you bind it to a property you can use value converters. For example if you want to view an element if […]

  8/4/2014 - 11:03 AM

Building a tabbed app using Xamarin.Forms

Xamarin.Forms is one of the biggest news with Xamarin 3. With Xamarin.Forms you can build UI for 3 platforms (Windows Phone, iOS and Android) with one shared codebase. What is unique for Xamarin.Forms is that the UI code you are writing with Xamarin.Forms will render native UI controls. That means that the UI will look […]

  7/28/2014 - 11:29 AM

Debug Android emulator remotly

When developing apps for Android I’m using Xamarin and Visual Studio. I’m running Windows under Parallels.Therefor I can’t use the x86 emulator with HAXM for hardware acceleration. But Android emulator is really slow without hardware acceleration, because of that i running the emulator on the host OS, in my case OS X. To set up remote […]

  6/18/2014 - 11:21 AM

TechDays 2014

Den 19-20 november (17-20 november med pre-conf inkluderat) anordnas utvecklarkonferensen TechDays av Microsoft. Jag och min Sogeti- och IO2GameLabs kollega Johan Karlsson har fått äran att vara med på den. Vi kommer att prata om det vi brinner mest för nämligen cross platform utveckling för mobila enheter. På pre-conf (den 17 november) kommer vi tillsammans […]

  6/17/2014 - 11:18 AM

Xamarin and MvvmCross

A way to reuse so much code as possible when working with Xamarin is to use the MVVM-pattern. A framework for MVVM that works great with Xamarin is MvvmCross (http://www.nuget.org/packages/MvvmCross/3.1.1). This blog post shows the basics about to use MvvmCross with Xamarin for an Android app. More posts about Xamarin and MvvmCross will come later. […]

  5/27/2014 - 6:52 AM

Xamarin, Invalid or Corrupt License

If you get this message when developing Android apps with Xamarin, “Invalid or Corrupt License” it does not necessary means that it is something wrong with the licens. In my case it was API level 19 that caused the problems. After I unistalled it from SDK Manager I have not seen the message.  This seems to be […]

  1/27/2014 - 9:09 AM

Windows Azure Mobile Services in Portable Class Library

In my current project, a multiplayer game for mobile devices I only using Windows Azure Mobile Services as backend. The game will be available for multiple platforms and I will use Xamarin for iOS and android. When using Xamarin I can reuse a lot of code if I using PCL (Portal Class Library) that i […]

  1/7/2014 - 12:14 PM

Size limit on app download when using 3G

iOS and Windows Phone has size limit on how big apps you can downloaded when you’re not connected to a Wi-Fi-network. Windows Phone has a limit on 20 Mb and iOS has 50 Mb.  Android has not that type of limit, but an APK on Google Play is limited to 50 Mb, but you can […]

  5/15/2013 - 10:16 AM

Authentication with Azure Mobile Services

When developed the multiplayer part of WordRoom we discussed to use different authentication providers. But it was a lot of code to integrate each provider. And we wanted more than one. Instead we developed our own solution. But just ask yourself, do you want to create an account everywhere with different username and passwords. I […]

  4/10/2013 - 8:03 PM

A first test version of WordRoom for android is soon ready!

Now we have a full playable version of WordRoom for android. Next week we will proparly start to share packages for test users. If you are interesting to help us with testing, please send us an email to [email protected] We want your name, email address, phone model and running android version.

  2/19/2013 - 2:53 PM

Developing apps with mono

WordRoom started as a Windows Phone project, the third client we started to develop and the first one we released was for Windows 8. We developed the windows 8 relative fast because we could reuse a lot of the code from the Windows Phone project in that we used portal library for the core logic. […]

  2/6/2013 - 11:09 AM