My Sqlite inset, but whe I read it there is none

Question

public class Contact : ViewModelBase {

    [PrimaryKey, AutoIncrement]
    public int Id { get; set; }

    private string _Name;
    public string Name {
        get { return _Name; }
        set {
            if (_Name != value) {
                _Name = value;
                RaisePropertyChanged();
            }
        }
    }

    private string _PhoneNumber;
    public string PhoneNumber {
        get { return _PhoneNumber; }
        set {
            if (_PhoneNumber != value) {
                _PhoneNumber = value;
                RaisePropertyChanged();
            }
        }
    }

    private string _Address;
    public string Address {
        get { return _Address; }
        set {
            if (_Address != value) {
                _Address = value;
                RaisePropertyChanged();
            }
        }
    }
}

}

using System.ComponentModel;
using System.Runtime.CompilerServices;

namespace ContactXam.ViewModel {
public class ViewModelBase : INotifyPropertyChanged {

    #region Notify Property Changed Members
    public event PropertyChangedEventHandler PropertyChanged;
    protected void RaisePropertyChanged([CallerMemberName] string propertyName = "") {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
    #endregion
}

}

Answer 1

when I save a contact and come POP the page, I don't see my new contact, I have to restart the app to see

To update the UI at runtime, please make sure the model class inherits from the INotifyPropertyChanged interface or the BindableObject class to raise the PropertyChanged event such as:

   public class TestModel : INotifyPropertyChanged  
   {  
       private string content;  
       public string Content  
       {  
           get  
           {  
               return content;  
           }  
           set  
           {  
               if (content != value)  
               {  
                   content = value;  
                   NotifyPropertyChanged("Content");  
               }  
           }  
       }  
     
       protected virtual void NotifyPropertyChanged([CallerMemberName] string propertyName = "")  
       {  
           PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));  
       }  
       public event PropertyChangedEventHandler PropertyChanged;  
   }  

Check the doc: https://learn.microsoft.com/en-us/xamarin/xamarin-forms/xaml/xaml-basics/data-bindings-to-mvvm

Answer 2

Here is a simple example of my code to insert 1 or many of something