pagination with command

Sources/ClientMAUI/VMApp/ChampionListPageVM.cs

@@ -14,17 +14,9 @@ namespace ClientMAUI.VMApp
 
         public DataManagerVM DataManagerVM { get; private set; }
 
-        public ICommand NextPageCommand { get; private set; }
-        public ICommand PreviousPageCommand { get; private set; }
-
         public ChampionListPageVM(DataManagerVM dataManager)
         {
             DataManagerVM = dataManager;
-
-            NextPageCommand = new Command(
-                execute: () => DataManagerVM.PageId++
-                );
-            PreviousPageCommand = new Command( execute: () => DataManagerVM.PageId-- );
         }
     }
 }

Sources/ClientMAUI/Views/Pages/ChampionListPage.xaml

@@ -37,9 +37,9 @@
         </ListView>
 
         <HorizontalStackLayout HorizontalOptions="Center">
-            <Button Text="&lt;" Command="{Binding PreviousPageCommand}"/>
+            <Button Text="&lt;" Command="{Binding DataManagerVM.PreviousPageCommand}"/>
             <Label Text="{Binding DataManagerVM.PageId}" Padding="5"/>
-            <Button Text="&gt;" Command="{Binding NextPageCommand}"/>
+            <Button Text="&gt;" Command="{Binding DataManagerVM.NextPageCommand}"/>
         </HorizontalStackLayout>
     </VerticalStackLayout>
 

Sources/VM/DataManagerVM.cs

@@ -1,6 +1,8 @@
 using LolToolkit;
+using Microsoft.Maui.Controls;
 using Model;
 using System.Collections.ObjectModel;
+using System.Windows.Input;
 
 namespace VM
 {
@@ -17,6 +19,8 @@ namespace VM
                 {
                     _pageId = value;
                     OnPropertyChanged();
+                    (PreviousPageCommand as Command).ChangeCanExecute();
+                    (NextPageCommand as Command).ChangeCanExecute();
                     LoadData();
                 }
             }
@@ -24,6 +28,19 @@ namespace VM
         }
         public int _pageId = 1;
         public int PageSize { get; set; } = 5;
+        public int NbItem
+        {
+            get => _nbItem;
+            set
+            {
+                if( _nbItem != value)
+                {
+                    _nbItem = value;
+                    OnPropertyChanged();
+                }
+            }
+        }
+        public int _nbItem;
 
         public IDataManager DataManager
         {
@@ -38,16 +55,29 @@ namespace VM
         }
         private IDataManager _dataManager;
 
+        public ICommand NextPageCommand { get; private set; }
+        public ICommand PreviousPageCommand { get; private set; }
+
         public DataManagerVM(IDataManager dataManager)
         {
             DataManager = dataManager;
             ChampionVMs = new ReadOnlyObservableCollection<ChampionVM>(ChampionsObs);
+
+            NextPageCommand = new Command(
+                execute: () => { PageId++; },
+                canExecute: () => { return NbItem - (PageSize * (PageId-1)) > PageSize ; }
+                );
+            PreviousPageCommand = new Command(
+                execute: () => { PageId--; },
+                canExecute: () => { return PageId > 1; }
+                );
         }
 
         public async void LoadData()
         {
             ChampionsObs.Clear();
-            IEnumerable<Champion?> champions = await DataManager.ChampionsMgr.GetItems(PageId - 1, PageSize);
+            NbItem = await DataManager.ChampionsMgr.GetNbItems();
+            IEnumerable<Champion> champions = await DataManager.ChampionsMgr.GetItems(PageId - 1, PageSize);
             foreach (var item in champions)
             {
                 ChampionsObs.Add(new ChampionVM(item));