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App Current Properties not being saved

KelveKelve Member ✭✭
in Xamarin.Forms

Hi,

I am using App.Current.Properties to know if user has already logged in and redirect him to main page instead of the login page.
However, it seems that the property i am saving for that is not getting saved and i dont know why.

Here is the code when i save the property after the user logged in

public WelcomePage ()
{   
    InitializeComponent();
    App.SetProperties("IsLoggedIn", true);
    ...
}

App class:

...
            bool isLoggedIn = Application.Current.Properties.ContainsKey("IsLoggedIn") ? Convert.ToBoolean(GetProperties("IsLoggedIn")) : false;
        //HERE ALWAYS GIVES ME FALSE NO MATTER WHAT
            if (!isLoggedIn)
            {
                ///colocar login page depois
                MainPage = new NavigationPageGradientHeader(new LoginPage())
                {
                    LeftColor = Color.FromHex("#4195D3"),
                    RightColor = Color.FromHex("#0058A8")
                };

            }
            else
            {
                MainPage = new NavigationPageGradientHeader(new MainPage())
                {
                    LeftColor = Color.FromHex("#4195D3"),
                    RightColor = Color.FromHex("#0058A8")
                };

and function to add property

        public async static void SetProperties(string property, object value)
        {
            var app = (App)Application.Current;
            app.Properties[property] = value;
            await app.SavePropertiesAsync();
        }
Tagged:

Answers

  • JohnHardmanJohnHardman GBUniversity admin

    @Kelve

    (1) Are you testing on Android by any chance?
    If so, in Visual Studio, go to Tools/Options/Xamarin/Android Settings
    and then ensure that "Preserve application data cache on device between deploys" is checked.

    (2) If you are using an emulator, see what happens on a physical device.

    Regarding your code:

    (3) Use async Task or async Task<T> rather than async void for the signature of async methods, other than event handlers.

    (4) Will you ever set the IsLoggedIn property to false? If not, you can simplify the line
    bool isLoggedIn = Application.Current.Properties.ContainsKey("IsLoggedIn") ? Convert.ToBoolean(GetProperties("IsLoggedIn")) : false;
    to
    bool isLoggedIn = Application.Current.Properties.ContainsKey("IsLoggedIn");

    (5) To avoid typing errors causing problems, do not keep repeating the hard-coded string "IsLoggedIn". Use a static string instead that uses static initialisation and that is accessed everywhere you currently use the hard-coded string.

  • ColeXColeX Member, Xamarin Team Xamurai
    1. Ensure that App.SetProperties("IsLoggedIn", true); has been called in WelcomePage , i see when you first login in , the page is LoginPage , does WelcomePage locates in navigation stack after Login Page ?
    2. What's the code in method GetProperties ?

    Modify the code to

    bool isLoggedIn = Application.Current.Properties.ContainsKey("IsLoggedIn") ? (Application.Current.Properties["IsLoggedIn"] as bool) : false;
  • KelveKelve Member ✭✭

    @JohnHardman said:
    @Kelve

    (1) Are you testing on Android by any chance?
    If so, in Visual Studio, go to Tools/Options/Xamarin/Android Settings
    and then ensure that "Preserve application data cache on device between deploys" is checked.

    (2) If you are using an emulator, see what happens on a physical device.

    Regarding your code:

    (3) Use async Task or async Task<T> rather than async void for the signature of async methods, other than event handlers.

    (4) Will you ever set the IsLoggedIn property to false? If not, you can simplify the line
    bool isLoggedIn = Application.Current.Properties.ContainsKey("IsLoggedIn") ? Convert.ToBoolean(GetProperties("IsLoggedIn")) : false;
    to
    bool isLoggedIn = Application.Current.Properties.ContainsKey("IsLoggedIn");

    (5) To avoid typing errors causing problems, do not keep repeating the hard-coded string "IsLoggedIn". Use a static string instead that uses static initialisation and that is accessed everywhere you currently use the hard-coded string.

    (1) Not just android.The option is checked. Im also debbuging to a real iOS device through wifi and it is also not working.
    (4) Yes, i will set when the user logs out.

  • KelveKelve Member ✭✭

    @ColeX said:
    1. Ensure that App.SetProperties("IsLoggedIn", true); has been called in WelcomePage , i see when you first login in , the page is LoginPage , does WelcomePage locates in navigation stack after Login Page ?
    2. What's the code in method GetProperties ?

    Modify the code to

    bool isLoggedIn = Application.Current.Properties.ContainsKey("IsLoggedIn") ? (Application.Current.Properties["IsLoggedIn"] as bool) : false;
    1. Yes, it has been called.
    2. I have removed it since it didnt work.
  • ColeXColeX Member, Xamarin Team Xamurai
    edited September 2019

    I test on my side everything is fine , could you provide a basic project for us to reproduce ?

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