Using Azure Maps with a Xamarin Forms app Part 3 – Route Directions

This is the third in a three part series where I build a Xamarin Forms app that uses the Azure Maps service. You can check out the other parts here:

Part 1 – Basic text search
Part 2 – Search by Category
Part 3 – This post.  Routing

In this post I’ll show you how I was able to query the Azure Maps Route Directions Endpoint and render the route on a map.  The route directions API endpoint takes a number of parameters, of which I only use a few.  Mainly, the source location lat and long, and the destination location lat and long.  The URI I construct ends up looking like this

For this demo, I let the user choose from a few hard coded source and destination locations.  For each preconfigured source and destination, I looked up the latitude and longitude, and stored them with the option.  When the user selects from one of the source and destination pairs, I pass the associated latitude/longitude coordinates to the API.  This is just a demo, so a real solution could be more dynamic by allowing the user to query for directions based on points of interest also returned by the API.  For this post, I’m returning the route for Stanford University to Pizzeria Delfina in Palo Alto, California.  (Palo Alto is the default simulated location for the Android Emulator).  Here’s a screenshot of the view where a user selects from one of the locations.  Its just a few buttons.

Here’s the resulting route drawn as an overlay on the phone’s native map. I was able to draw the polyline overlay using this technique for Xamarin Forms Maps.

Here’s what the code looks like for when the user clicks a button and the view loads to query the API based on the hard coded choice selection and render the map. (pay no attention to the async void lol)

To start I’m using a switch statement based on the user’s selection and passing the hard coded lat long to the API. Notice I’m instantiating the map AFTER I get the results back from the query. This was because of the way the overlay is drawn on to the map for Xamarin Forms. It involves creating a custom renderer which listens to when the map is instantiated. At first, the overlay wasn’t drawing on the map because I was instantiating the map before making the API call, and the listener on the custom renderer was running and rendering the map before the results of the route query were returned. This is one of the rare cases where I personally declare UI in code, to control the declaration timing at run time. After I instantiate the map I place a pin on the starting point no matter which route is chosen. Then I place a pin on the selected destination.

So there you have it. I’ve always been a sucker for POI, mapping etc so I’m excited to be able to explore the mapping API more.

Using Azure Maps with a Xamarin Forms app Part 2 – Search by Category

This is the second in a three part series where I build a Xamarin Forms app that uses the Azure Maps service. You can check out the other parts here:

Part 1 – Basic text search

Part 2 – This post.  Search by category
Part 3 – Routing

In this post, I’ll cover searching by category using the Get Search by Category API endpoint which allows you to search points of interest (POI) by a list of categories.   Calling the search by category service is actually pretty easy.  The endpoint URL is much like the text search endpoint, except for a couple different parts.  Here are the text search and category search URIs compared:

Text search (fuzzy)

Category search

I’m passing the required additional parameters and optional lat long for category search, so ultimately my URI call looks like this:

You need to pass your api key, a strongly recommended country set limiting parameter, the api version, return format (json), and a lat long.

In my Xamarin app, I built a simple page with a button upon which clicked, takes you to a page with a listview of categories.  When you click a category, I pass the selected category back to the previous page, perform the search and render the results as map pins on the map.

To make it more visually appealing, I’m using a mix of Font Awesome and Material Design icons in the category select page.  I was able to get the icons to render using the Iconize Plugin for Xamarin Forms   nuget packages.  It was a little tricky getting the packages to work as .NET Standard 2.0 is not supported on the latest stable versions, so I had to install the pre-release versions.  Ultimately I’m using the base Xam.Plugin.Iconize package two additional separate packages that each load a set of fonts, Xam.Plugin.Iconize.FontAwesme and Xam.Plugin.Iconize.Material

Here’s what my select category page looks like complete with icons:

Here are the results after you select a category.

Now to dig into the code details a little.  To make the category select page, I bind a listview to a category viewmodel

I create a list of this viewmodel and bind it to the list declared in my Xaml. The listview contains an item template that renders the icon as well as the display text of each category

Here’s the code to populate my list of viewmodel. You can see its a mix of Material Design and Font Awesome icons. The ‘fa-‘ and ‘md-‘ text triggers the ‘Iconize’ element to render from the icon set of Font Awesome and Material Design accordingly, based on whatever icons are included in the project by installing the nuget packages for that icon set.

When a category is chosen, I pass the selected category back to the referring page, make the API call and deserialize the Json into a model I created by pasting the Json into QuickType IO

Here’s what the code behind on that page looks like

You can see I’m attempting to grab the user’s location and pass it to the API along with the category selected.  That’s about it.  The Azure Maps service is proving to be pretty awesome.  I’ve been waiting for something like this for years.  It makes it easy to add location intelligence to your apps!  Happy coding.

Building a Xamarin Android app in Visual Studio Team Services and deploying to App Center

In the old days, we use to build our Xamarin apps with Visual Studio and find a way to get the resulting .apk file to the end user for them to install.  Then came Hockey App.  It was and sort of still is (in transition) a distribution platform for Xamarin apps.  It was awesome.  Now of course, we have App Center, a completely modern and full fledged mobile app management and distribution service by Microsoft.  Since Microsoft purchased Xamarin, App Center was the next logical step and is among the many benefits of the acquisition.  Not surprisingly, using Microsoft’s Visual Studio Team Services (VSTS) you get integration with App Center.  Namely, you can configure build definitions in VSTS that allow you to deploy right to App Center.   Before we take that for granted let’s pause and let that sink in for a moment.  What this means is that when I check in my code, it triggers the build definition in VSTS which builds the code in the cloud on a hosted Xamarin agent, then deploys the resulting .apk file to App Center.   I can wash my hands of the mundane, boring task of building in Visual Studio, and manually updating App Center forever!  Dev Ops is all the rage right now, and I must admit, although building a single build and deploy definition is merely dabbing my feet in the water, this stuff can get pretty addictive.  Its like life hacking but with code.  The more I can automate my CI/CD (cringe) pipeline the better.

To get started, I’m going to assume you have a VSTS subscription and a project with a code repository set up.  I’ll assume you have an App Center account and an established Android application.  You can get help with those Here and Here.

To get started with your build definition, navigate to your project and select builds.  Then click the button to create a new definition.


Select the type and location of the source code you’re going to build.


Now we’re given the option to select a template.  Here we’ll search for Xamarin and select the Xamarin Android template.


Now the template is loaded and ready for us to configure as our build definition.  It contains steps that will execute in the order they are listed from the top down.  Templates are great for newbies like me in that they guide us on the right path.  Notice the first step that sets the cloud build environment to use Nuget 4.4.1.  This is a requirement and is already set up for you.  The next step is the Nuget restore step and will pull down the any nuget packages for your code.  I’ve actually set a custom nuget feed in addition to the regular official nuget to that pulls down some extra packages from a private source.   This is set up as a custom Service Endpoint and not covered here.

Next, configure the build step to your liking.  The defaults for this step pretty much work.  Make sure you use JDK version 8 and JDK architecture x64.


In the next step, upload the Keystore File that will be used to sign your app and enter the alias and password.


The default settings for the “publish artifact: drop” step should already be ok. After that, we’ll configure the deploy step that will send our app on over to App Center.  I’m skipping the optional ‘Test with Visual Studio App Center’ step that allows you to queue and run unit tests for the deployed code in App Center’s Test Cloud.

The App Center distribute step requires you to set up a service endpoint (pictured below) connection to App Center.  Follow the link above to set that up.


Go back to the App Center distribute step and configure the following:

– The App Center app slug. The app slug is how the build step locates your app in App Center. This is how you find out what your app slug is in App Center as described by Team Services:

“The app slug is in the format of {username}/{app_identifier}. To locate {username} and {app_identifier} for an app, click on its name from, and the resulting URL is in the format of{username}/apps/{app_identifier} . If you are using orgs, the app slug is of the format {orgname}/{app_identifier}.”

– Enter your desired release notes. You can direct the step to use a specially formatted release file here. I haven’t messed around with this specifically as I trigger the builds manually anyway, and I just fill in the release notes by hand.

– Select an App Center distribution group to publish to by filling in the group ID. If you select none, the default group will be used. To find the ID of a distribution group in App Center, go to the group and select the gear icon to change the group settings. The ID will be displayed there.

Save the definition and you’re ready to go! You just hacked life and saved time by letting VSTS do some work for you.

Say goodbye to debugging Xamarin iOS on a different machine with Remoted iOS Simulator (for Windows)

The Remoted iOS Simulator (for Windows) just came out for Visual Studio, and if you haven’t tried it, I definitely recommend doing so if you are tired of remoting into your MAC build server to debug your Xamarin iOS apps.

The Remoted iOS Simulator allows you to “Test and debug iOS apps entirely within Visual Studio on Windows”.  I must say having tried it out, I found it works as advertised!  It’s wonderful to be able to run a fully live, real iOS app in a simulator window locally.  It saves time as I don’t have to remote into my Mac build server or be physically near it to interact with a running app.

Simply download the installer, run it, and you’re good to go.  Set your iOS Xamarin project as the startup project.  When you hit ‘debug’ a local iOS simulator pops up and runs locally right on your machine.  You can interact with the app as it runs on the Mac.

The simulator has some basic but useful features like locking the home screen, setting the location, and the ability to rotate and shake the device.

Here is a screenshot of a map view in a real app.  Giddy!  Best of all, the simulator stays running and connected to your Mac after you stop debugging so can use a live Xaml previewer like Gorilla Player for design time visuals.  This is one breakthrough that deserves full applause from the masses.

An app running in the Remoted Simulator for Visual Studio on Windows