In The Visual Studio Blank App Template, Where Dgould I Out My Code?

Overview

In a recent post to software decision makers, I discussed reasons businesses should consider cross-platform native evolution over website development. Y'all can read the previous Xamarin Tutorial post hither.

In the post, I gave a instance to use the Xamarin toolset, why it should be considered, and why information technology could exist a skilful business and development conclusion for your arrangement.

In this Xamarin Tutorial series, I will be building a solution that can be used equally a starting point for cross-platform applications using the Xamarin toolset. Today I will exist focusing on the following:

What is Xamarin?
How to Setup the Xamarin evolution environs using Microsoft Visual Studio
Briefly talk almost iOS support
Discuss Shared vs Portable Form Libraries (PCL) strategies and how to use both
Connecting to your Mac to debug an iOS version of your application
Using the Visual Studio iOS Simulator to debug your iOS awarding

Xamarin – What is it?

Before we outset diving into creating our solution, I will include a snippet from the post mentioned higher up that gives you an overview of Xamarin. After this explanation, my assumption will be that y'all at to the lowest degree know what information technology is and why nosotros are using it.

Xamarin is a Microsoft owned company that started with the engineers that created the popular Mono, Mono for Android and MonoTouch, which are cross platform implementations of the Common Linguistic communication Infrastructure (CLI) and the Common Language Specifications, too known as .NET.

Xamarin uses a shared C#/.NET codebase along with either Xamarin Studio or Visual Studio, to write native Android, iOS, and Windows Apps. Did yous empathize that? Yes, native applications. Wow, so, all your lawmaking is 100% shared. Again, not exactly. But, close.

For near simple UI patterns, Xamarin.Forms allows you build native user interfaces for iOS, Android and Windows using 100% shared C#. It also includes dozens of controls and layouts which are mapped to native controls in their respective platform.

Depending on your application needs, all the same, you may need to access a platform specific feature, such equally Alive Tiles for Windows, or maybe y'all need to create a custom control that isn't a native control for any of the platforms. In these scenarios, Xamarin provides a means to call into platform specific code. Nonetheless, cheque this out, … expect for information technology … wait for it … information technology is yet in C#.

Image of what you get when you use Xamarin and Xamarin.Forms

So, every bit you can come across, the App Logic and most of the user interface code is shared across all platforms. In fact, there is even a community of user-congenital components that y'all can leverage in your application using both NuGet and the Xamarin Component Store.

Development Environment – The Microsoft Way

At present that we have the basic definition and understanding of what Xamarin is, we can put that behind the states and make certain that we have the tools necessary to start developing. For this, my program is to stick with as many Microsoft technologies as possible.

Visual Studio

And so, first in this Xamarin Tutorial, I am going to assume that you are using Windows 10 and have a flavor of Visual Studio 2015 installed on your car. Even nether that assumption, we need to make sure that you have the Xamarin tools installed. Luckily, this is easy.

Showtime, make sure that you don't accept any instances of Visual Studio currently running.

Next, open your Windows Settings awarding and type add or remove in the search box. Select Add together or remove programs from the dropdown list.

Image showing to select Add or remove programs from the dropdown list in Windows Settings.

You will be taken to the Apps and Features section of settings. Curlicue down and select Microsoft Visual Studio 2015. At present select Modify.

Image of the Apps & features section of Windows Settings suggesting to click on Modify Microsoft Visual Studio Enterprise 2015 with Updates.

You volition be prompted to requite permission to the installer. Give it permission past selecting Yes. You should see the Installation programme initializing.

Image of installation program initializing.

If you didn't shutdown Visual Studio 2015 before you selected Modify, the installer will notify you and recommend that you close Visual Studio now. If you did forget to close Visual Studio or skipped that step entirely, close Visual Studio at present and select Retry.

Image saying to remember to close your Visual Studio windows.

If Visual Studio is closed, the installer should provide you lot an selection to modify the current installation. Select Modify.

Image telling you to modify the current installation

After selecting Modify, you will see a list of all the features currently installed. Since our goal in this Xamarin Tutorial series is to create a cross platform application, verify that all the Cross Platform Mobile Development features are enabled. We aren't going to use all of features, but if you know you are going to do cross platform development and you have the space, install it now and forget it, you will take all the tools necessary for the future.

Image of how you should verify that all the Cross Platform Mobile Development features are enabled

Since I already have the features installed, I tin can be bodacious that all the necessary tools are installed for me to start developing cross platform applications. If some of the features weren't enabled for you, brand sure they are and select Update. This will install all the tools for you.

iOS Support

If we plan on having iOS support for our application, Xamarin.Forms does support it. So, yep, you tin can create iOS applications on Windows using C#.Net. However, yous will need a networked Mac running Bone X Yosemite (x.10) & to a higher place with XCode seven installed. You volition also need to install the Xamarin.iOS tools onto the Mac. The best way to exercise this is to use the Xamarin Unified Installer, which will install everything y'all demand. Y'all can view these instructions here.

I will presume that y'all accept XCode and the Xamarin.iOS tools setup on your Mac. Even so, I will discuss how to adhere to your Mac, build and run/debug the awarding later on in the postal service.

One thing we can do right now is setup the permissions to allow united states to debug our awarding on the iOS simulator on the Mac.

Commencement, on your Mac, search for Remote Login in Spotlight.

Image telling you to search for "remote login" on your Mac.

Select Sharing. Select Remote Login and brand sure that your account is in the list of Allow Access for: Only these users. I am an Administrator on my Mac, so I volition just allow all Administrators.

Select "Remote Login" and allow access to necessary users.

Note: You could allow All Users to take remote access, simply, I am not sure that is a good idea.

Your Mac should now be discoverable in Visual Studio. Once more, nosotros will talk more most this later.

Create a New Project

Blank Application

Now we tin can create our new project. Open Visual Studio, select File, New, Project…

Create a new project in Visual Studio.

Next, select Installed, Templates, Visual C#, Cantankerous-Platform. Then, select Cantankerous Platform App (Xamarin.Forms or Native). Enter the name of your projection. Brand sure the directory is correct and then select OK.

More steps of creating your new project.

Another dialog prompting for the blazon of cross-platform project will be displayed. Select Blank App, Xamarin.Forms, Shared Project and then select OK.

Dialog box telling you to select Blank App, Xamarin.Forms, Shared Project and then select OK

Visual Studio volition start creating your Xamarin solution. However, since we are targeting Universal Windows Platform applications in our projection, you will be prompted for your Target and Minimum versions of Windows. I have chosen to target Windows 10 Anniversary Edition with a Minimum version of Windows 10 (Build 10586). Once you have made your selection, select OK.

Select your target version and minimum version for your new Universal Windows Project.

You will also probably run across the following dialog while it is creating the solution.

Dialog box that says Creating project 'XamarinBlog.Android'...

When information technology is finished, you should notice that there are several projects in your solution. One for each of the platforms we will target with our application.

Image showing the several projects in your solution.

Along with the iOS, Android and UWP projects, yous should too notice that at that place is a Shared project. I know, I kind of blew past that office when I had you select the Code Sharing Strategy shared project. I did this on purpose, I volition explicate this in more than detail at present.

Xamarin uses a couple of strategies for sharing lawmaking within our Xamarin solution: Shared and Portable Class Library (PCL).

Shared Strategy

The shared strategy basically takes each file in the shared projection and compiles it under each of the other projects. Think of it as making a copy of the files in the shared project into each specific platform project then doing a build. You can however practice platform specific code in the shared projection past using #if compiler directives, but exist cautious, your code can, and probably volition, become ugly fast.

Annotation: the shared project isn't really a traditional project that gets built into an assembly. You tin can't actually build it.

Portable Course Libraries (PCL)

With portable class libraries, the code is compiled separately and referenced in each project like whatsoever normal form library. The big difference here is that you have access to a subset of .Cyberspace that is compatible with all the target platforms. So, for example, yous could use System.Net.Http, but trying to access hardware, such as, the camera API is not available. You could, still, use a generalized interface that uses dependency injection.

Both Shared and Portable?

So, as yous can see, each strategy mentioned above, contains some pros and cons. So, it really depends on the type of application and how much external sharing you lot are going to demand to do with the code. Simply put, if yous are going to share code outside of the awarding itself, PCL's are a good option. All the same, if this is a old application with no externally shared lawmaking, the shared strategy would be a skilful choice.

That existence stated, what if we want to employ both? Can nosotros practise that? To reply your question, yes. What if you have a lot of shared code between applications, just you lot as well have a significant amount that is just shared beyond your specific awarding?

In fact, let'southward add together a PCL to our projection for any code that nosotros might want to share with other applications we write in the future. Nosotros won't do annihilation with it right at present other than wire it upward for use in my next weblog postal service.

First, right-click on the solution, select Add together and then select New Project…

Start a new project in your solution explorer.

From here, we desire to repeat the same steps we used to create the solution, but in this case, we want to select a class library. Select Installed, Cross-Platform, Course Library (Xamarin.Forms). Enter the proper name of your shared class and select OK.

Image showing to select the Class Library.

Okay, now, one thing you should know is, by default, the project volition add a Xamarin ContentPage, XamarinBlog.CommonServices.cs. You tin go ahead and delete it now.

Delete the Xamarin ContentPage that was created called XamarinBlog.CommonServices.cs

Okay, we at present have a portable grade library in our solution, however, it isn't being referenced. Then, get alee and reference information technology in each of the platform specific projects by right clicking on references and selecting Add Reference…

Select Add Reference under References.

Select Projects, then Solution, and so select your new PCL from the list. Finally, select OK.

Image of what to select in the Reference Manager.

Okay, now that we accept our PCL referenced in each projection, y'all should be able to build most of the projects. As far as the iOS project, we actually haven't talked almost how to connect to your Mac for building, and so let's do that quickly.

Connecting to the Mac

For us to build our iOS projection, nosotros will need to connect your Visual Studio iOS project to a Mac. To do this for the first time, all you practice is attempt to build the project. Right-click on the project and select Build. If you haven't connected earlier, Visual Studio will brandish instructions for setting up the remote login functionality on your Mac. Since we already did this before in the post, nosotros will skip them and select Next. If yous would like, you lot can plow off the instructions for next time, however, if you lot are similar me, I forget the "setup one time and forget" things, so I usually get out mine unchecked.

Image of the first step in connecting your Visual Studio iOS project to a Mac.

You will now be prompted to pick your Mac. For information technology to show upward in the list, you must take setup remote access properly and the Mac bust be on the same network equally Visual Studio. Select your Mac and then select Connect.

Select your Mac and connect to it.

Adjacent, you volition exist prompted for your username and password. Enter your credentials and select Login.

Enter your username and password to securely connect to your Mac.

Once you have selected Login, it volition attempt to connect to your Mac. If it is successful, you volition see a link under the Icon for the machine you selected. Once yous see this, select Shut.

A link will be displayed on your Mac icon if the connection is successful.

Now, go alee and try to build. I should build successfully if everything on your Mac is setup correctly.

Can I see Something?

I know, nosotros accept done a lot upwardly to this point and nosotros haven't seen a darn thing. Well, before we run the application, I exercise desire to mention a couple more things. Showtime, let's look at where this whole application starts in code. Where is the application object for this thing?

In the shared project, XamarinBlog, open up App.xaml.cs.

open App.xaml.cs

Find this is where our Application object for all our projects resides. How do we know what page to load starting time? Cheque out the constructor. Notice that we assign XamarinBlog.MainPage to the MainPage property of our application. Also, yous may accept noticed that at that place are a number of events that are created for the states: OnStart(), OnSleep() and OnResume(). These are awarding lifecycle events that get fired for each platform. We will probably talk more than about these in subsequently posts in this serial.

Application lifecycle events in the constructor.

Let's look at the XamarinBlog.MainPage object in Mainpage.xaml and see if nosotros tin figure out what this page is going to be presenting us. Select MainPage.xaml.

Select MainPage.xaml

Looking at the markup, we come across we are creating a ContentPage with a label, that has the text 'Welcome to Xamarin Forms!", and information technology is centered in the middle of the page.

Image of the markup saying "Welcome to Xamarin Forms!"

At present that we know what it is supposed to do, let's encounter it in action. Build and run the application for each platform and see what you become. Information technology should look something similar the post-obit:

Xamarin application run in iOS 10.2 Xamarin application run in Android Xamarin application run in Windows

Absurd, correct? Three platforms, mostly the same code. Well at least the UI, and then far.

Using Visual Studio iOS Simulator

It is nice to be able to debug on your Mac, merely I must admit, it is kind of a pain at times to be forced to sit down by the automobile to examination your application. Well, a cool new feature for Visual Studio is the Visual Studio iOS Simulator. This add-in for Visual Studio allows us to debug our iOS version of the app correct on our estimator. So, yous don't need to be nigh your Mac to practice the debugging. You can exercise it right on your PC.

To go the add-in, download the installer hither. You might accept to restart Visual Studio for changes to have result. Once you exercise, brand certain that you select iPhoneSimulator and run the application again.

Get the add-in to debug on your Mac and make sure you select iPhoneSimulator.

You lot should run into the Visual Studio iOS Simulator with your application.

Image of the Visual Studio iOS Simulator with your application.

If for some reason, yous would like to disable the Visual Studio add-in and go back to debugging your iOS application on the Mac you tin practise so. All you need to do is select Tools from the main menu and then select Options…

Image showing how to disable the Visual Studio add-in.

Scroll down to the Xamarin tab and select iOS Settings. Uncheck the Remote Simulator to Windows checkbox and select OK.

Image showing to uncheck the Remote Simulator to Windows checkbox and select OK

At present, you should be able to debug on your Mac again.

Summary

So, to summarize what nosotros learned in the outset part of our Xamarin Tutorial series:

We answered the question, "What is Xamarin?"
Nosotros Setup the development environment using Microsoft Visual Studio
Briefly talked about iOS support in Xamarin and Visual Studio
Pointed out the differences between the Shared and Portable Class Libraries (PCL) strategies and how to use both
Demonstrated how to connect to your Mac to debug the iOS version of your application
Installed Visual Studio iOS Simulator and ran our iOS application on our PC

In Role 2 of this Xamarin Tutorial series, we will talk well-nigh implementing the Model-View-ViewModel pattern using the MVVM Low-cal Toolkit to maintain a solid separation of concerns. So, stop back and continue your journey with me on developing cross-platform applications using Xamarin.

I hope you lot enjoyed this post. If and then, please feel free to share with others.

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