SQlite Xamarin forms Visual Studio 2019 Local Database

Majid Sarrouh 1 Reputation point
2021-01-19T14:15:51.853+00:00

Hiiiiiiiiiii

I designed an app that I published in the google play store
The app uses aLocal database (SQlite) to enable the user to register once and use the app for a limited period of 1 year only.
But...
the problem is that when a user installs my app, he can easily go to the settings of his Android phone, click on Apps
then look for the installed app
and click on Storage

and
Clear All Data
stored in the local database

by doing so, he will be able to use it again as if it is the first time.

So the trial period is useless in this case

HOW to disable the "Clear All Data" in the storage?

NOTE: If we cannot disable the clear data option beecause it's a function of the device how can we save the data in a way that cannot be erased in a LOCAL SQLITE DATABASE.

Is there a way???????????

Please help

Xamarin
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A Microsoft open-source app platform for building Android and iOS apps with .NET and C#.
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SQL Server
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A family of Microsoft relational database management and analysis systems for e-commerce, line-of-business, and data warehousing solutions.
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C#
An object-oriented and type-safe programming language that has its roots in the C family of languages and includes support for component-oriented programming.
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  1. JarvanZhang 23,936 Reputation points
    2021-01-20T09:50:46.257+00:00

    Hello,​

    Welcome to our Microsoft Q&A platform!

    Where did you store the database? In Android, external storage has two different ways: public and private files. Private files are files that are specific to your application, these files will be removed when uninstalling the application or clearing the application data.

    Public files that are not considered to be specific to the application and are meant to be freely shared. These files will not be removed if you uninstall the app. To keep the database when clearing the application data, try to store the database as the public path.

    Check the doc:
    https://learn.microsoft.com/en-us/xamarin/android/platform/files/external-storage?tabs=windows#public-external-files

    Best Regards,

    Jarvan Zhang

    If the response is helpful, please click "Accept Answer" and upvote it.

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

  2. Majid Sarrouh 1 Reputation point
    2021-01-22T16:33:57.763+00:00

    Can you put these codes in a sample very simple project done with Visual Studio Community version (2019) Xamarin forms Please?

    The first Page that opens when the app icon is clicked is a called LoginPage.xaml
    It contains a sub page called LoginPage.xaml.cs containing the code that when run allows the user to enter the email address and his name just the first time the app is run after installation.
    At this first time run, the data and time are stored in the public file and will be used anytime later the app is opened again

    The second time the app is opened, the code in the LoginPage.xaml.cs contains a code that when run allows the user to;

    1- either go to a new page called HomePage.xaml and start using the app IF THE DIFFERENCE IN DATE IS LESS THAN 1 MONTH (difference between the stored date and the current date when the app is accessed the second time)
    2- stay in the same page and a message box will be displayed announcing the end of the trial period

    ALL THE CODES ARE WRITTEN AND RUNNING CORRECTLY WITHOUT ANY PROBLEM BUT JUST THE CODE WRITTEN IN THE LoginPage.xaml.cs STORES THE DATE IN SQLite database and this date can be deleted when the storage section of the app is accessed in the phone setting and Data is Cleared. This is what I do not want to happen.

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  3. Majid Sarrouh 1 Reputation point
    2021-01-25T12:29:29.537+00:00

    Can you put these codes in a sample very simple project done with Visual Studio Community version (2019) Xamarin forms Please?

    The first Page that opens when the app icon is clicked is a called LoginPage.xaml
    It contains a sub page called LoginPage.xaml.cs containing the code that when run allows the user to enter the email address and his name just the first time the app is run after installation.
    At this first time run, the data and time are stored in the public file and will be used anytime later the app is opened again

    The second time the app is opened, the code in the LoginPage.xaml.cs contains a code that when run allows the user to;

    1- either go to a new page called HomePage.xaml and start using the app IF THE DIFFERENCE IN DATE IS LESS THAN 1 MONTH (difference between the stored date and the current date when the app is accessed the second time)
    2- stay in the same page and a message box will be displayed announcing the end of the trial period

    ALL THE CODES ARE WRITTEN AND RUNNING CORRECTLY WITHOUT ANY PROBLEM BUT JUST THE CODE WRITTEN IN THE LoginPage.xaml.cs STORES THE DATE IN SQLite database and this date can be deleted when the storage section of the app is accessed in the phone setting and Data is Cleared. This is what I do not want to happen.

  4. Majid Sarrouh 1 Reputation point
    2021-01-25T19:02:27.237+00:00

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  5. Majid Sarrouh 1 Reputation point
    2021-01-26T19:15:28.52+00:00

    Dear JarvanZhang

    Yes I am facing some troubles with implementing the code you suggested to me. I have limited knowleedge in databases connected to apps and I just need to store ONE Date in an external file the first time my app is used by a user and each time the app is accessed the app will compare the current date to the stored date and if the difference is less that 1 month, the used is allowed to access and if not the access is denied.

    In the first time the date is to be stored in the external public file, when the user is asked to give permission to store or not the date, if he does not accept the user will not be granted access to the app.

    Kindly find attached some pictures of the errors faced60682-errors-to-fix.png