Uncategorized

Uno – One Platform to Rule Them All

First, we should start off with what Uno is and why you should care.

As stated on their website, Uno is “The only platform for building native mobile, desktop and WebAssembly apps with C#, XAML from a single codebase. Open source and professionally supported.”

What does this mean?

Well if you have any experience (or not) building a mobile app and a subsequent web app, you have essentially had to build both separately, outside of potentially sharing data through an API.

Before Xamarin, you would even have had to build the iOS and Android apps separately using different languages (Swift/Objective-C and Java/Kotlin respectively). Uno introduces a way to build for iOS, Android, Web, and UWP using shared logic and UI.

This is huge.

Sharing logic between platforms has been the “easy” part for developers. Sharing UI, however, is not. There is a huge difference in UI between Android and iOS and even larger differences between web and mobile. Xamarin.Forms allows us to share UI for Android and iOS but we were still on our own for the web.

Uno enables you to write the UI once, then, using native controls, deploys native UI look and feel to each of your platforms. This means, you write the same code for a button regardless of the platform the button is for, and the user will see the native button for their platform.

How does it work?

The Uno Platform works differently depending on what you’re building.

The platform specific UI is created by taking the visual tree and rendering into what the platform supports:

iOS – UI Kit

Android – ViewGroups and Views

Web – Native controls

The logic is also deployed differently for each platform.

When building a UWP app, Uno runs on top of, well, UWP and WinUI. When building Android and iOS apps, Uno runs on top of the Xamarin Native Stack. Finally, when you’re building a Web App, Uno runs on top of WebAssembly. The mobile apps and web apps all run with Mono runtime. When it all comes together, it looks a little like this:

unodiagram

Well this looks nice, but what’s really happening under the hood?

Let’s break it down:

Android and iOS

  1. You write your C# and XAML code in Visual Studio
  2. Uno takes the code and lets you add any Xamarin specific libraries or tools
  3. Mono runtime executes the C# code

This process is essentially the same as regular Xamarin. The big difference between Xamarin and Uno comes with the ability to run the same UI on the Web.

Web Apps –

  1. You reuse both your logic and UI that you wrote for your mobile apps.
  2. Uno uses the Web Assembly Bootstrapper to take any .NET standard library and execute these files in the JavaScript console.
  3. Mono runtime then executes the code

The ability for Uno to utilize Web Assembly (which is what allows you to write your code in C# and not JavaScript) is what makes Uno so unique.

UWP –

  1. You reuse both your logic and UI that you wrote for your mobile apps and Web Assembly Apps.
  2. Your code is run through the Windows UI which does not need the Mono runtime to execute.

The big difference here is that UWP apps already have the Windows namespaces and do not need to reference the Uno.UI. The benefit Uno provides here is the ability to reuse the code you’ve already written for mobile and web.

Now that we have an idea of how this beauty works, let’s write some code!

To get started with Uno, follow their instructions here: https://platform.uno/docs/articles/get-started.html

When you create your Uno solution in Visual Studio, there is a similar feel to when you create a Xamarin.Forms solution because of the different projects created for you. Here is a look at the projects that are auto-created:

2019-10-01_1528

As you would see in a Xamarin.Forms project, there are separate projects for each platform and a single shared project. The Droid, iOS, UWP, and Wasm projects are all the same as if you had created a blank app for each, the only difference being references to the Uno UI. The magic happens in the Shared project.

Similar to the Shared project in Xamarin.Forms, this is where you will write all your shared logic and UI. Uno provides support for the MVVM, a design pattern many developers are familiar and comfortable with.

So, what does a finished product look like?

Here are examples of each platform using the “TODOS” Demo App from Uno.

iOS

iOS

Android

Android

Web

WASM

UWP

UWP

These projects all use logic and UI from the shared project. Code once, four apps.

Let’s talk debugging.

Debugging in Uno can be a bit different depending which platform you are trying to debug.

Android and iOS – For mobile, you will use the same Mono debugger you are used to using in Visual Studio, with access to all your favorite breakpoints, value changes, etc.

Web – Currently there is only support for chromium debugging, which means Chrome and Edge.

UWP – Here, the tooling comes from .NET studios which is not as efficient with the mono runtime.

Want to try out Uno but don’t want to go through the steps to get set up through Visual Studio?

Then checkout their playground!

2019-10-02_1518

The Uno Playground is a fun and easy way to look at how different items render on different platforms. They make it quick and easy to try out new styles and is great for beginners and tutorials.

What are future features we can look forward to?

  1. Support for MacOS or Linux.
  2. More features from UWP API
  3. Support for smart watches

The true beauty of Uno is that it encompasses what we as developers should all be striving to accomplish – building on top of each others’ accomplishments. We don’t need to re-create the wheel, real innovation happens when you stand on the shoulders of giants and we all move upwards.

Happy coding.

Authored by me, originally posted through freeCodeCamp

Uncategorized

Xamarin.Forms vs Xamarin Native

If you’re new to Xamarin (or not), one of the first decisions you’re faced with when starting a new project is whether to use Xamarin.Forms or Xamarin Native. In this article, we’ll go through descriptions of each and which situations are suited best for one or the other.

First, what is the difference?

xamarinforms

Image Source: Xamarin Docs

Xamarin.Forms is a way to write your app in C# once, and it will run on both Android and iOS through a shared code base for the logic AND the UI. Xamarin.Forms runs on top of native platforms.

Xamarin Native creates a wrapper around the native APIs for each platform which allows the same look and feel of an app that was built without Xamarin. But, Xamarin developers can build both Android and iOS in C# and have access to the tools offered in the C# community. Xamarin Native requires that you build each app separately, but also allows for more specific configuration for both Android and iOS.

But what about speed?

Altexsoft did an extensive test on speed of native apps, Xamarin Native apps, and Xamarin.Forms apps. You can see the full report here . For bootup speed, native apps are always faster, followed by Xamarin Native apps, and finally Xamarin.Forms.

bootspeed
Image Source: Altexsoft

You will also notice that Android and iOS have significantly different speeds. This is something to keep in mind for your project and whether your users are more likely to be using Android or iOS.

Secondly, if your app is retrieving its data from a REST API, you’ll be concerned about those speeds as well:

restspeed
Image Source: Altexsoft

Here, the speeds between Xamarin and native are more similar. In fact, Xamarin Android is even a bit faster than the native Android apps.

With all this information, here is a quick guide for when to use each product.

Situations best suited for Xamarin.Forms:

• Apps requiring little platform specific UI
• Apps that need to be built quickly
• Apps that require heavy code sharing

Situations best suited for Xamarin Native:

• High level of platform specific UI
• Apps that need to be as small and as fast as possible
• Apps that require platform specific UI

At the end of the day, there is no wrong choice, Xamarin is best way to build your cross-platform mobile apps.

If you want to dive deeper into Xamarin.Forms or Xamarin Native, read up on the docs here.

Uncategorized

Using lookup tables (join tables) in Entity Framework

Very rarely, if ever, do we come across a situation in programming where an entire application relies on isolated database tables that do not have share data between each other. So, then, how do you use Entity Framework to help these tables communicate?

Solution: Join Tables

There are several relationship types your Entity Framework Entities can have with each other.

  1. One-to-One
  2. One-to-Many
  3. Many-to-Many

One-to-One can be handled simply by using a foreign key. For simplicity sake, let’s say we have a Dog class and an Adopter class. A dog can only have one adopter and an adopter can only adopt one dog. Here is what the class setup looks like:

Dog Class:

public class Dog  
{ 
    public string Id { get; set; }
    public string Name { get; set; }
    
    public virtual Adopter Adopter {get; set}
}

Adopter Class:

public class Adopter 
{
    public string Id { get; set; }
    public string Name { get; set; }
    public string DogId {get; set;}
    
    public virtual Dog Dog {get; set}
}

When this is compiled by Entity Framework, the Id of the Dog with be placed in the virtual Dog column of the Adopter table and the Id of the Adopter will be placed in the virtual Adopter column of the Dog table. And that’s it. Simple.

For a One-to-Many relationship, let’s say an Adopter can adopt multiple dogs (as it should be), but a dog can still only have one Adopter.

This is what the class setup will look like:

Dog Class:

public class Dog  
{ 
    public string Id { get; set; }
    public string Name { get; set; }
    
    public virtual Adopter Adopter {get; set}
}

Adopter Class:

public class Adopter 
{
    public string Id { get; set; }
    public string Name { get; set; }
    public string DogId {get; set;}

    public virtual ICollection Dogs {get; set;}
}

Here, the Dog Class stays the same since it can still only have one Adopter. However, the Adopter class looks a little different. Instead of a single foreign key, we have a collection of Dogs. In the database this looks like a list of Dog Ids.

Finally, we have the Many-to-Many relationship. In this situation, a Dog can have many Adopters and and Adopter can have many Dogs. Now, following the pattern above, you may think that we would just set up a virtual collection in both the Dog and Adopter classes. This, however, is not the case. Instead, we need what is called a Binding or Join Table.

Join Tables allow Many-to-Many relationships in Entity Framework by matching the necessary data (normally an Id).

Here is what our classes will look like:

Dog Class:

public class Dog  
{ 
    public string Id { get; set; }
    public string Name { get; set; }
    
    public virtual ICollection AdoptionMember {get; set;}
}

Adopter Class:

public class Adopter 
{
    public string Id { get; set; }
    public string Name { get; set; }
    
    public virtual ICollection AdoptionMember {get; set;}
}
public class AdoptionMember 
{
    public string Id { get; set; }
    public string AdoptionDate { get; set; }
    public int AdoptionFee { get; set;}
    public string DogId {get; set;}
    public string AdopterId {get; set;}
    
    public virtual Dog Dog { get; set; }
    public virtual Adopter Adopter { get; set; }
}

Notice that there is a third class, the AdoptionMember. Both the Dog and Adopter classes will have a collection of the AdoptionMember class. The AdoptionMember class has single Foreign Keys for each the Dog and Adoption classes. The AdoptionMember class also has shared data such as the Adoption Date and the Adoption Fee for each individual adoption.

This is a very basic overview of the most common data relationship types you will run into using MVC and how to set up your data when using Entity Framework Code First method.

Uncategorized

Selectable Enum Dropdown List Using TagHelpers

This post is going to look into how populate a dropdown list with the contents of an enum using a TagHelper and an HTML Helper.

In case you aren’t familiar with TagHelpers, TLDR:

TagHelpers use server-side code to render HTML concisely and is readable for those not familiar with Razor markup.

If you want to learn more, checkout the docs here.

Alright, let’s dive in with our setup!

Enum:

public enum DogName
{
       Fido,
       Buddy,
       Bear
}

Model:

public class Dog
{
      public DogName DogName{ get; set; }
}

Make sure both the class and property are public.

View:

In the beginning of your view, be sure to bind the Model:

@model RescueShare.Models.Dog

Then, using our <select> TagHelper in our Razor View to create the actual dropdown:

<select asp-for="DogName"
asp-items="Html.GetEnumSelectList<DogName>()">
</select>

The asp-for attribute binds the values to the DogName property. Then, asp-items populuates the dropdown with values from our DogName enum using our GetEnumSelectList HTML Helper.

Here are the major benefits for using a TagHelper in this scenario:

  1. Ability to access server-side data
  2. Concise and easy to read
  3. Works with Intellisense

And that’s it! We have gone through how to successfully bind a <select> TagHelper to an enum in a Razor View using an HTML Helper for an ASP.NET Core MVC app!