fix data binding issue

src/Banquale/Banquale/App.xaml.cs

@@ -15,11 +15,12 @@ public partial class App : Application
 
 		MyManager.DataLoad();
 		MyManager.Persistence = new DataContractPersistance.DataContractPers();
-		MyManager.DataSave();
 
 		InitializeComponent();
 
 		MainPage = new AppShell();
+        //MyManager.DataSave();
+
 
     }
 }

src/Banquale/Banquale/Model/Account.cs

@@ -3,11 +3,13 @@ using System.Collections.Generic;
 using System.ComponentModel;
 using System.Diagnostics;
 using System.Linq;
+using System.Runtime.Serialization;
 using System.Text;
 using System.Threading.Tasks;
 
 namespace Banquale.Model
 {
+    [DataContract]
     public class Account : INotifyPropertyChanged
     {
 	public event PropertyChangedEventHandler PropertyChanged;
@@ -17,9 +19,10 @@ namespace Banquale.Model
             PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
         }
 
+        [DataMember]
         public double Balance 
         {
-            get => Balance;
+            get => balance;
             set
             {
                 if (balance == value)
@@ -31,7 +34,7 @@ namespace Banquale.Model
         private double balance;
 
 
-
+        [DataMember]
         public string Name 
         {
             get => name;
@@ -45,6 +48,8 @@ namespace Banquale.Model
         }
         private string name;
 
+
+        [DataMember]
         public string IBAN 
         {
             get => iban;
@@ -66,7 +71,8 @@ namespace Banquale.Model
             IBAN = iban;
         }
 
-        public List<Transactions> TransactionsList { get; set; }
+        [DataMember]
+        public List<Transactions> TransactionsList { get; set; } = new List<Transactions>();
 
         //public bool DoTransactions(string name, string IBAN, float sum)
         //{
@@ -97,7 +103,7 @@ namespace Banquale.Model
 
         internal static void AskForHelp(Entry request, Entry subject, Editor message)
         {
-            Debug.WriteLine(request);
+            Debug.WriteLine(request.Text);
             Debug.WriteLine(subject);
             Debug.WriteLine(message);
             Debug.WriteLine("Help button pressed !");

src/Banquale/Banquale/Model/Customer.cs

@@ -12,7 +12,7 @@ namespace Banquale.Model
     public class Customer : Person
     {
         [DataMember]
-        public List<Account> AccountsList { get; private set; }
+        public List<Account> AccountsList { get; private set; } = new List<Account>();
 
         //private uint NbAccounts { get; set; } = AccountsList.Count;
 

src/Banquale/Banquale/Model/Transactions.cs

@@ -1,7 +1,9 @@
 using System.ComponentModel;
+using System.Runtime.Serialization;
 
 namespace Banquale.Model
 {
+    [DataContract]
     public class Transactions : INotifyPropertyChanged
     {
 
@@ -9,6 +11,8 @@ namespace Banquale.Model
         {
             PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
         }
+
+        [DataMember]
         public int Type
         { 
             get => type;
@@ -20,9 +24,11 @@ namespace Banquale.Model
                 OnPropertyChanged(nameof(Type));
             }
         }
+        [DataMember]
 
         private int type;
 
+        [DataMember]
         public Double Sum 
         {
             get => sum;
@@ -34,8 +40,10 @@ namespace Banquale.Model
                 OnPropertyChanged(nameof(Sum));
             }
         }
+        [DataMember]
         private Double sum;
 
+        [DataMember]
         public Account InvolvedAccounts
         {
             get => involvedAccounts;
@@ -47,8 +55,10 @@ namespace Banquale.Model
                 OnPropertyChanged(nameof(InvolvedAccounts));
             }
         }
+        [DataMember]
         private Account involvedAccounts;
 
+        [DataMember]
         public string Category
         {
             get => category;
@@ -60,8 +70,10 @@ namespace Banquale.Model
                 OnPropertyChanged(nameof(Category));
             }
         }
+        [DataMember]
         private string category;
 
+        [DataMember]
         public DateTime Date 
         {
             get => date;
@@ -73,6 +85,7 @@ namespace Banquale.Model
                 OnPropertyChanged(nameof(Date));
             }
         }
+        [DataMember]
         private DateTime date;
 
         public Transactions(int type, Double sum, Account involvedAccounts, string category, DateTime date)

src/Banquale/Banquale/Stub/Stub.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using Banquale.Model;
 
 namespace Banquale.Stub
@@ -21,13 +22,24 @@ namespace Banquale.Stub
             Transactions Transactions2 = new Transactions(1, 54.99, Account2, "Test", new DateTime(2022, 8, 15));
             Transactions Transactions3 = new Transactions(0, 1000, Account3, "Test", new DateTime(2020, 9, 1));
 
-            Console.WriteLine(Customer1);
+            Debug.WriteLine(Customer1.Name, Customer1.Password);
             List<Customer> CustomersList = new List<Customer>();
             List<Transactions> TransactionsList= new List<Transactions>();
-            List<Account> AcountsList = new List<Account>();
+            List<Account> AccountsList = new List<Account>();
-            AcountsList.Add(Account1);
+            
-            AcountsList.Add(Account2);
+
-            AcountsList.Add(Account3);
+
+            Account1.TransactionsList.Add(Transactions1);
+            Account2.TransactionsList.Add(Transactions2);
+
+            //AccountsList.Add(Account1);
+            //AccountsList.Add(Account2);
+            //AccountsList.Add(Account3);
+
+            Customer1.AccountsList.Add(Account1);
+            Customer1.AccountsList.Add(Account2);
+
+
 
             CustomersList.Add(Customer1);
             CustomersList.Add(Customer2);

src/Banquale/Banquale/Views/BalancePage.xaml

@@ -42,7 +42,7 @@
                     TextColor="Black"
                     HorizontalOptions="Center"/>
                 <Label
-                    Text="{Binding AccountList[0].Balance}"
+                    Text="{Binding CustomersList[0].AccountList[0].Balance}"
                     Grid.Column="1"
                     MinimumWidthRequest="70"
                     TextColor="Black"