How to Create an Azure Back-End for a Xamarin.Forms Application - Part Two

Alain Natalini

6y23k24100Article

C#Azure SQL Xamarin Database Azure SQL DatabaseBack-EndXamarinFormsXamarinForms Back-End

24 Comments

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Waseef k5y ago
Hi Alain, Can't able to find the Zumoappnameservice sample in github in the Provided link, can you please guide me from where can i get the Proper sample?
- Alain Natalini5y ago
  Hi Waseef. Thank you for your interest. You are right: the GitHub repository provided in my article has been archived because some parts of the code is deprecated. I'll update the article with the correct link as soon as possible. Stay tuned and thanks again.
Paco Doso5y ago
I'm not able to "Publish" the ZUMOAPPNAMEService from Visual Studio for Mac: I don't have the option. However, I can build and deploy the app locally. Is this normal?
- Paco Doso5y ago
  It seems that you opened the solution with "Open folder", which is not possible on Visual Studio for Mac. For my side, I've opened the "ZUMOAPPNAME" solution from the "backend\dotnet\Quickstart" folder. Then I'm able to build/rebuild/clean solution, to run it locally, but I don't have the way to publish it.
- Alain Natalini5y ago
  Ok. Let me recreate the issue. Please, give me some time for understanding the problem. Thanks again.
- Alain Natalini5y ago
  Hi Paco. Thank you for your interest. The short answer is "no, it isn't". But, please, bear with me and let me understand better: the application runs in local, but you can't create a web session with it, do I understand well?
Jacobo Mena5y ago
Hi, my table was created, the items are saving when i click on +, but the items are not displaying. Please help me :(
- Jacobo Mena5y ago
  Hi, apologyze me, i updated the packages installed in the zumoappname.ios, then is reading thank you. THAT WAS THE SOLUTION.
- Alain Natalini5y ago
  I'm glad to hear that you solved. BTW, I'm here to help. Thank you again.
- Alain Natalini5y ago
  Hi Jacobo. Thank you for your interest about my article. I'm trying to reproduce your issue. I'll be back in a while. Thanks for your pacience.
Bernardo Flores5y ago
Hello, I followed the steps carefully and is a match with https://docs.microsoft.com/en-us/previous-versions/azure/app-service-mobile/app-service-mobile-xamarin-forms-get-started, I get all the screens ok, however, there is no table created on the DB hence App stores nothing. What could be wrong? I am using an Azure for Students suscription btw but all was created ok on Azure
- Bernardo Flores5y ago
  Never mind, I just had to restart the AppService after publishing it. I did the whole thing twice until it ocurred to me that maybe changes when publishing needed a restart to take effect. voila !!
- Alain Natalini5y ago
  Hi Bernardo. Glad to hear You solved. BTW, I'm here to help: don't esitate to ask me anything about. Thanks for your interest and stay tuned.
Elias Georgiou6y ago
Wanted to ask some stupid questions.
- Elias Georgiou6y ago
  1) If someone take this app in his hands, lets say a hacker or something, can he get in and find out the connection string and see the login and password to the SQL Database? 2) lets say thi is the finished app, can someone do SQL injection? i want to know if i need to take more steps to be more protected, thank you in advance
- Elias Georgiou6y ago
  Thank you. Much apreciated
- Alain Natalini6y ago
  Hi Elias.Thank you for your interest and don't worry: your questions aren't stupid. So, let's start: 1. The connection string is added at Azure level, hence the access to data is secure and it's tokened for the application. Of course, if someone has the access to your application (stealing your phone, for example), he'll be able to access to your database. 2. The Azure Database is secure and encrypted. All newly created databases in SQL Database are encrypted by default by using service-managed transparent data encryption. To learn more about, you can refer to the following official documents: https://docs.microsoft.com/en-us/azure/azure-sql/database/secure-database-tutorial. https://docs.microsoft.com/en-us/azure/azure-sql/database/security-overview. https://docs.microsoft.com/en-us/learn/modules/secure-your-azure-sql-database. https://docs.microsoft.com/en-us/azure/azure-sql/database/transparent-data-encryption-tde-overview?redirectedfrom=MSDN&view=sql-server-ver15&tabs=azure-portal. There is also a great article here, about SQL Injection attacks and Cross-site scripting attacks: https://microsoft.github.io/AzureTipsAndTricks/blog/tip254.html Hope I've answered clearly. Happy coding and thank you again.
Elias Georgiou6y ago
Hello, thank you for this guide, it worked.
Cary Baer6y ago
Thanks for posting this. Don't you have to create a table in the database? I followed Part 2, but since there is no ToDo table, it doesn't work.
- Alain Natalini6y ago
  Hi Cary. Thanks for your interest. It's not necessary to manually create the table. it's the code that creates it for us. See the files: TodoItem.cs, TodoItemManager.cs, zumoappnamecontext.cs. Indeed, if you use Microsoft SQL Server Management Studio, you'll see the table. Please, follow carefully the tutorial, paying attention to the dependencies update. Thanks again and feedback me.
Boni Ivane6y ago
Thank you Natalini your solution worked wonderfully. Currently, I am fighting with the client side I have an error: Assembly 'Xamarin.Android.Support.CustomTabs' is using '[assembly: Android.IncludeAndroidResourcesFromAttribute]', which is no longer supported. Use a newer version of this NuGet package or notify the library author.ZUMOAPPNAME.Droid. I tried to update the nuget packet but nothing
Boni Ivane6y ago
Thank you for the second part, I am a beginner in xamarin and your tutorial brings me a plus. I downloaded the sample application from the associated GitHub repository.https://github.com/Azure/azure-mobile-apps-quickstarts and open on Visual Studio 19, I am currently unable to build the code because Visual Studio is showing me errors. An example of the mistakes I am facing: Error CS1061 'TodoItem' does not contain a definition for 'Id' and no accessible extension method 'Id' accepting a first argument of type 'TodoItem' was not found (a using directive or an assembly reference is- missing?) ZUMOAPPNAMEService C: \ Users \ HP \ Downloads \ Compressed \ azure-mobile-apps-quickstarts-master \ azure-mobile-apps-quickstarts-master \ backend \ dotnet \ Quickstart \ ZUMOAPPNAMEService \ Controllers \ TodoItemController.cs 43 Active
- Alain Natalini6y ago
  Hi Ivane. Thanks for your interest. I'm going to reproduce your issue. Be patient with me for a while. Thank you again.
- Alain Natalini6y ago
  Hi Ivane, I reproduced your issue and I've solved with this Work Around: 1. Unzip the downloaded folder. 2. Extract the inner folder from the unzipped one. 3. Rename the extracted folder to azuremobileappsquickstarts 4. Open the folder in VS2019. 5. Expand the nodes to open the ZUMOAPPNAMEService.sln solution 6. Right-click on the project name. 7. Click on "Restore Nuget Packages". 8. Rebuild solution. Please feedback me about. Thank you so much again.

Introduction

Welcome to the second part of the article on "How to create an Azure Back-End for a Xamarin.Forms Application".

In the first part of the article, we've seen how to create:

Resource Group
Web App
Azure SQL Database
Azure Server

You can read the first part here.

In this second part, we'll see how to,

Deploy the SDK for .NET solutions to Azure.
Connect a basic ToDo application built with Xamarin.Forms to the Azure Back-End and the Azure SQL Database.

For simplicity, we'll use the code shared in the related GitHub repository by Microsoft.

Prerequisites

A Microsoft Azure Subscription (if you don't have one yet, see the Azure Portal for a free subscription).
Microsoft Visual Studio 2019 (all versions).

Step 1 - Add the connection string to the Web App.

First of all, we have to add the Azure SQL Database connection string to the Web App.

Login into the Azure Portal with your credentials.
Click on the name of the Web App (Type App Service)

How To Create An Azure Back-End For A Xamarin.Forms Application

Click on Configuration in the left-hand column.

Click on New connection string

Compile the fields with the correct data and then click on save.

Step 2 - Deploy the SDK for .NET to Azure.

First, download the SDK for .NET, and the sample application from the related GitHub Repository.

https://github.com/Azure/azure-mobile-apps-quickstarts

Now, we'll work on Visual Studio:

Launch the IDE and select the folder we downloaded in the previous step.

In Solution Explorer, expand the tree, as shown in the following picture.

Open the ZUMOAPPNAME.sln solution and build it.
Right-click on ZUMOAPPNAMEService and select Publish.

Click on Start, then select App Service - Select Existing - Advanced.

Insert the Connection String under MS_TableConnectionString, check Update database and save.

Now select the Web App created on Azure.

We'll see something like in the following picture.

Now, click on +Add in the Dependencies line, select Azure SQL Database and then click on next.

Compile the fields with the correct data and then click on finish.

We'll see something like the following.

Click on Publish to deploy the SDK for .NET to Azure.

Step 3 - Deploy the Xamarin.Forms Application.

Now we'll work on the Xamarin.Forms application.

In Solution Explorer, expand the tree as shown in the following picture.

Open the ZUMOAPPNAME.sln solution.
Open the Contents.cs file.
Replace the string after the @ with the WebApp URL we created on Azure.

Verify the build configuration for Android and iOS.

Finally, launch the application (Ctrl + F5).
Add a task to the Android or iOS application, then pull to refresh both the emulators and we'll see the added task in both the lists.

SUCCESS!!! We've created an Azure back-end for our own Xamarin.Forms application.

Conclusion

In this article, we've seen how to:

Deploy the SDK for .NET solutions on Azure.
Connect a basic ToDo application built with Xamarin.Forms to the Azure Back-End and the Azure SQL Database.

How you have seen, we used the ready-to-use solutions from the GitHub Repository by Microsoft without modifying it, just for simplicity.

Of course, this is the base for your own future projects where you want to create an Azure back-end for your Xamarin.Forms application, and

you can modify the code to do it (please, read the LICENSE.txt file).

Don't forget to delete the Resource Group from Azure when your test is completed to avoid unwanted costs (the procedure to do it is at the end of Part One of this article).

Sources

Microsoft Official Documentation,
https://docs.microsoft.com/it-it/azure/app-service-mobile/app-service-mobile-xamarin-forms-get-started
Related GitHub Repository
https://github.com/Azure/azure-mobile-apps-quickstarts

Thank you for your time and your attention.