CODEWITHSUNDEEP
c#xamarin.formsbindingsingleton
giani.sim
giani.sim

Reputation: 277

Xamarin Forms C#: Reflect instance property changes anywhere it is used

I am developing a Xamarin Forms app. I have a singleton class implemented in this way:

public class DataManager
{
    static readonly Lazy<DataManager> _instanceHolder =
    new Lazy<DataManager>(() => new DataManager());

    public static DataManager Instance => _instanceHolder.Value;
    //private constructor to prevent multiple instances of DataManager
    private DataManager(){} 

    private UserModel _loggedUser;
    public UserModel LoggedUser
    { 
        get
        {
            return _loggedUser;
        }

        set
        {
            _loggedUser = value;
        }
    }
}

Then, in several class I "linked" the LoggedUser property of the Instance of DataManager in this way:

public class Test
{
    public UserModel User
    {
        get 
        {
            return DataManager.Instance.LoggedUser;
        }
    }
}

However, anytime I change the LoggedUser property, both changing one of its property or reassigning a new object to it, changes are not reflected in the classes where LoggedUser is used (in this case in the Test class). How do I "retrigger" the get once the LoggedUser Property change inside the DataManager instance?

Upvotes: 0

Views: 61

Answers (1)

Bruno Caceiro
Bruno Caceiro

Reputation: 7189

You will have to implement the NotifyPropertyChanged.

public class DataManager : INotifyPropertyChanged
{
    // Singleton


   private UserModel _loggedUser;
   public UserModel LoggedUser
   { 
      get
      {
        return _loggedUser;
      }

    set
    {
        _loggedUser = value;
        OnPropertyChanged("LoggedUser");
    }
}

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged == null)
            return;

        PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
}

Upvotes: 1

Related Questions