Xamarin Forms on DVLUP

Using Windows IoT, SignalR, Azure Custom Vision and Xamarin Forms to Flush a Toilet

Thu, 13 Feb 2020 00:00:00 +0000

My cat uses the human toilet. However, he doesn’t know how to flush when he’s done. So, I thought, “Why not train a custom trained machine learning model to know when to flush the toilet for him? That way, I can go on vacation without asking friends to stop by.”

That single thought began my trip through some great modern developer tools and tech to build a full solution for the problem. In this post, I’ll walk you through everything and you can explore the code and parts list here https://github.com/LanceMcCarthy/Flusher .

Custom TypingStarted and TypingEnded Events

Thu, 02 Jan 2020 00:00:00 +0000

You know that little indicator in a chat that shows if someone is currently typing? I am working on a new post (coming soon, link will be here) that uses SignalR to communicate who is currently typing in a chat room along with the messages themselves.

To determine who is typing, I use a timer and the TextChanged event. The timer logic itself is straightforward, in the TextChanged event starts a timer.

Draw Your Own Xamarin Pie Chart dynamically

Thu, 18 Apr 2019 00:00:00 +0000

In this tutorial, I’ll show you how to draw your own pie chart just using lines and a list of data items. The code itself is in C#, but the concept can be used on any platform that has a drawing library and ArcSegments.

You can view the entire solution in this GitHub Gist . Okay, let’s get started!

Setting Up

The first thing you’ll need to understand is how the platform’s drawing library makes arcs. In this code, I’ll be using RadPath from Telerik UI for Xamarin most libraries work the same way. RadPath lets you use a custom Geometry which has RadArcSegment object, which has helpful StartAngle and SweepAngle properties.

Error XF001: Xamarin.Forms targets have been imported multiple times

Mon, 01 Oct 2018 00:00:00 +0000

If you’re in the process of updating a Xamarin.Forms app to a more modern style project set up (NET Standard 2.0, PackageReference, etc), you may get the following error.

Error XF001: Xamarin.Forms targets have been imported multiple times. Please check your project file and remove the duplicate import(s).

This can be because of the move to using PackageReference for your NuGet packages and a simple fix awaits you.

Close Visual Studio and navigate to the Solution in File Explorer
Delete the hidden .vs folder
Go into each affected project sub folder and delete the following files; project_name.nuget.props and project_name.nuget.targets
Open the solution in Visual Studio, do a Clean and Rebuild,

Migrating from PCLStorage to .NET Standard 2.0

Thu, 19 Apr 2018 00:00:00 +0000

If you’re a Xamarin Forms developer, you’ve likely used PCLStorage (or other Dependency Service) to interact with the target platform’s file system in the portable class library’s code. However, since November 2017, Xamarin.Forms now uses a .NET Standard 2.0 class library and PCLStorage is no longer supported.

System.IO.File

This isn’t a problem because in .NET Core 2.0 you now have access to System.IO.File’s GetFolderPath and SpecialFolder methods (see System.IO.File in .NET Core 2.0 docs ).