MauiSettings

A nuget to improve settings storage (locally and eventually in the cloud) on .NET MAUI projects.

The plugin idea is based on the Advexp.Settings.Local nuget by Alexey Ivakin
Repo: https://bitbucket.org/advexp/component-advexp.settings/src/master/
License: Apache-2.0 (https://licenses.nuget.org/Apache-2.0)

This project was created from scratch, however uses the basic idea to keep all Settings in the static object. All taken and changed files have been marked so.

Nuget

Get the latest version from nuget.org

Usage

Settings Object

In the .NET MAUI project, create a new Class (for instance SettingsApp.cs) holding your setting properties.

public partial class SettingsApp : MauiSettings<SettingsApp>
{
    
    #region Settings

    #region Version
    [MauiSetting(Name = nameof(App_SettingsVersion))]
    public static Version App_SettingsVersion { get; set; } = new("1.0.0");

    #endregion

    #region CloudSync
    [MauiSetting(Name = nameof(Cloud_ShowInitialPrompt), DefaultValue = true)]
    public static bool Cloud_ShowInitialPrompt { get; set; }

    [MauiSetting(Name = nameof(Cloud_ShowInitialPrompt), DefaultValue = SettingsStaticDefault.Cloud_EnableSync)]
    public static bool Cloud_EnableSync { get; set; }
    #endregion

    #region Theme 
    [MauiSetting(Name = nameof(Theme_UseDeviceDefaultSettings), DefaultValue = SettingsStaticDefault.General_UseDeviceSettings)]
    public static bool Theme_UseDeviceDefaultSettings { get; set; }

    [MauiSetting(Name = nameof(Theme_UseDarkTheme), DefaultValue = SettingsStaticDefault.General_UseDarkTheme)]
    public static bool Theme_UseDarkTheme { get; set; }

    [MauiSetting(Name = nameof(Theme_PrimaryThemeColor), DefaultValue = SettingsStaticDefault.Theme_PrimaryThemeColor)]
    public static string Theme_PrimaryThemeColor { get; set; }

    #endregion

    #region Localization

    [MauiSetting(Name = nameof(Localization_CultureCode), DefaultValue = SettingsStaticDefault.Localization_Default)]
    public static string Localization_CultureCode { get; set; }

    #endregion

    #region Secure

    // Encrypt: The value is encrypt before saving it on the device, and decrypt when loaded
    // Note: Only `Secure` properties can be encrypted
    [MauiSetting(Name = nameof(Localization_CultureCode), DefaultValue ="", Secure = true, Encrypt = true)]
    public static string User_Username { get; set; }

    // SkipForExport: Value is not added to the Dictionary when exporting the settings
    [MauiSetting(Name = nameof(Localization_CultureCode), DefaultValue ="", Secure = true, Encrypt = true, SkipForExport = true)]
    public static string User_Password { get; set; }

    #endregion

    #endregion
}

Load

To load the settings from the storage, call SettingsApp.LoadSettings() (mostly in the App constructor of your App.xmls file. The project uses the Maui.Storage.Preferences in order to store the settings on the corresponding device.

Save

Whenever you do make changes to a settings property of your class, call SettingsApp.SaveSettings(). This will write the settings to the storage.

Encryption

Starting from version 1.0.6, you can encrypt secure properties with a AESencryption. An example how it works is shown below. Sample: https://github.com/AndreasReitberger/MauiSettings/tree/main/src/MauiSettings.Example

App.xaml.cs

An example of how to load the settings from the App.xaml.

public partial class App : Application
{
    // Example key, it is recommended to generate the key on the device and save it as `Secure` property instead of
    // adding it in clear text to the source code.
    public static string Hash = "mYGUbR61NUNjIvdEv/veySPxQEWcCRUZ3SZ7TT72IuI=";
    public App()
    {
        InitializeComponent();

        // Example of how to generate a new key
        //string t = EncryptionManager.GenerateBase64Key();

        // Only Async methods do support encryption!
        _ = Task.Run(async () => await SettingsApp.LoadSettingsAsync(Hash));
        MainPage = new AppShell();
    }

    protected override void OnSleep()
    {
        base.OnSleep();
        if (SettingsApp.SettingsChanged)
        {
            try
            {
                SettingsApp.SaveSettings(Hash);
            }
            catch (Exception)
            {

            }
        }
    }
}

MainPageViewModel

An example of aViewModel loading and saving encrypted settings.

public partial class MainPageViewModel : ObservableObject
{
    #region Settings
    [ObservableProperty]
    bool isLoading = false;

    [ObservableProperty]
    string hashKey = App.Hash;

    [ObservableProperty]
    string licenseInfo = string.Empty;
    partial void OnLicenseInfoChanged(string value)
    {
        if (!IsLoading)
        {
            SettingsApp.LicenseInfo = value;
            SettingsApp.SettingsChanged = true;
        }
    }

    [ObservableProperty]
    ObservableCollection<SettingsItem> settings = [];
    #endregion

    #region Ctor
    public MainPageViewModel()
    {
        LoadSettings();
    }
    #endregion

    #region Methods
    void LoadSettings()
    {
        IsLoading = true;

        LicenseInfo = SettingsApp.LicenseInfo;

        IsLoading = false;
    }
    #endregion

    #region Commands
    [RelayCommand]
    async Task SaveSettings() => await SettingsApp.SaveSettingsAsync(key: App.Hash);

    [RelayCommand]
    async Task LoadSettingsFromDevice()
    {
        try
        {
            await SettingsApp.LoadSettingsAsync(key: App.Hash);
            LoadSettings();
        }
        catch(Exception)
        {
            // Throus if the key missmatches
        }
    }

    [RelayCommand]
    async Task ExchangeHashKey()
    {
        string newKey = EncryptionManager.GenerateBase64Key();
        await SettingsApp.ExhangeKeyAsync(oldKey: App.Hash, newKey: newKey);
        App.Hash = HashKey = newKey;
        LoadSettings();
    }

    [RelayCommand]
    async Task ToDictionary()
    {
        // All "SkipForExport" should be missing here.
        Dictionary<string, Tuple<object, Type>> dict = await SettingsApp.ToDictionaryAsync();
        Settings = [.. dict.Select(kp => new SettingsItem() { Key = kp.Key, Value = kp.Value.Item1.ToString() })];
    }
    #endregion
}

For more information, please see the example project.