diff --git a/Blazor/Blazor/Pages/Admins/AddAdministrator.razor.cs b/Blazor/Blazor/Pages/Admins/AddAdministrator.razor.cs
index 23b3d6a..ab898b7 100644
--- a/Blazor/Blazor/Pages/Admins/AddAdministrator.razor.cs
+++ b/Blazor/Blazor/Pages/Admins/AddAdministrator.razor.cs
@@ -9,13 +9,13 @@ namespace Blazor.Pages.Admins
         private AdministratorModel administratorModel = new();
 
         [Inject]
-        public IDataService DataService { get; set; }
+        public required IDataService DataService { get; set; }
 
         [Inject]
-        public NavigationManager NavigationManager { get; set; }
+        public required NavigationManager NavigationManager { get; set; }
 
         [Inject]
-        public ILogger<AddAdministrator> Logger { get; set; }
+        public required ILogger<AddAdministrator> Logger { get; set; }
 
 
         private async Task HandleValidSubmit()
diff --git a/Blazor/Blazor/Pages/Admins/Administrators.razor.cs b/Blazor/Blazor/Pages/Admins/Administrators.razor.cs
index d99d06e..718a4f1 100644
--- a/Blazor/Blazor/Pages/Admins/Administrators.razor.cs
+++ b/Blazor/Blazor/Pages/Admins/Administrators.razor.cs
@@ -11,26 +11,26 @@ namespace Blazor.Pages.Admins;
 
 public partial class Administrators
 {
-    public List<Administrator> administrators;
+    public List<Administrator> administrators = new();
 
     private int totalItem;
     [CascadingParameter]
-    public IModalService Modal { get; set; }
+    public required IModalService Modal { get; set; }
 
     [Inject]
-    public IDataService DataService { get; set; }
+    public required IDataService DataService { get; set; }
 
     [Inject]
-    public IWebHostEnvironment WebHostEnvironment { get; set; }
+    public required IWebHostEnvironment WebHostEnvironment { get; set; }
 
     [Inject]
-    public ILocalStorageService LocalStorage { get; set; }
+    public required ILocalStorageService LocalStorage { get; set; }
 
     [Inject]
-    public HttpClient Http { get; set; }
+    public required HttpClient Http { get; set; }
 
     [Inject]
-    public NavigationManager NavigationManager { get; set; }
+    public required NavigationManager NavigationManager { get; set; }
 
     private async Task OnReadData(DataGridReadDataEventArgs<Administrator> e)
     {
diff --git a/Blazor/Blazor/Pages/Admins/EditAdministrator.razor.cs b/Blazor/Blazor/Pages/Admins/EditAdministrator.razor.cs
index 3d91c64..9384c34 100644
--- a/Blazor/Blazor/Pages/Admins/EditAdministrator.razor.cs
+++ b/Blazor/Blazor/Pages/Admins/EditAdministrator.razor.cs
@@ -13,18 +13,18 @@ namespace Blazor.Pages.Admins
         private AdministratorModel administratorModel = new();
 
         [Inject]
-        public IDataService DataService { get; set; }
+        public required IDataService DataService { get; set; }
 
         [Inject]
-        public NavigationManager NavigationManager { get; set; }
+        public required NavigationManager NavigationManager { get; set; }
 
         [Inject]
-        public IWebHostEnvironment WebHostEnvironment { get; set; }
+        public required IWebHostEnvironment WebHostEnvironment { get; set; }
 
         [Inject]
-        public ILogger<EditAdministrator> Logger { get; set; }
+        public required ILogger<EditAdministrator> Logger { get; set; }
 
-        private string OldAdminName { get; set; }
+        private string OldAdminName { get; set; } = "";
 
         protected override async Task OnInitializedAsync()
         {
diff --git a/Blazor/Blazor/Pages/Chapters/AddChapter.razor.cs b/Blazor/Blazor/Pages/Chapters/AddChapter.razor.cs
index 098045b..731ea73 100644
--- a/Blazor/Blazor/Pages/Chapters/AddChapter.razor.cs
+++ b/Blazor/Blazor/Pages/Chapters/AddChapter.razor.cs
@@ -9,13 +9,13 @@ public partial class AddChapter
     private ChapterModel chapterModel = new();
 
     [Inject]
-    public IDataService DataService { get; set; }
+    public required IDataService DataService { get; set; }
 
     [Inject]
-    public NavigationManager NavigationManager { get; set; }
+    public required NavigationManager NavigationManager { get; set; }
 
     [Inject]
-    public ILogger<AddChapter> Logger { get; set; }
+    public required ILogger<AddChapter> Logger { get; set; }
 
 
 
diff --git a/Blazor/Blazor/Pages/Players/AddPlayer.razor.cs b/Blazor/Blazor/Pages/Players/AddPlayer.razor.cs
index e46e775..02aa732 100644
--- a/Blazor/Blazor/Pages/Players/AddPlayer.razor.cs
+++ b/Blazor/Blazor/Pages/Players/AddPlayer.razor.cs
@@ -9,10 +9,10 @@ namespace Blazor.Pages.Players
         private PlayerModel playerModel = new();
 
         [Inject]
-        public IDataService DataService { get; set; }
+        public required IDataService DataService { get; set; }
 
         [Inject]
-        public NavigationManager NavigationManager { get; set; }
+        public required NavigationManager NavigationManager { get; set; }
 
 
         private async Task HandleValidSubmit()
diff --git a/Blazor/Blazor/Pages/Players/EditPlayer.razor.cs b/Blazor/Blazor/Pages/Players/EditPlayer.razor.cs
index 1dd4d4a..9602858 100644
--- a/Blazor/Blazor/Pages/Players/EditPlayer.razor.cs
+++ b/Blazor/Blazor/Pages/Players/EditPlayer.razor.cs
@@ -13,13 +13,13 @@ namespace Blazor.Pages.Players
         private PlayerModel playerModel = new();
 
         [Inject]
-        public IDataService DataService { get; set; }
+        public required IDataService DataService { get; set; }
 
         [Inject]
-        public NavigationManager NavigationManager { get; set; }
+        public required NavigationManager NavigationManager { get; set; }
 
         [Inject]
-        public IWebHostEnvironment WebHostEnvironment { get; set; }
+        public required IWebHostEnvironment WebHostEnvironment { get; set; }
 
         protected override async Task OnInitializedAsync()
         {
diff --git a/Blazor/Blazor/Pages/Players/Players.razor.cs b/Blazor/Blazor/Pages/Players/Players.razor.cs
index 5035e2e..36a5214 100644
--- a/Blazor/Blazor/Pages/Players/Players.razor.cs
+++ b/Blazor/Blazor/Pages/Players/Players.razor.cs
@@ -17,23 +17,24 @@ public partial class Players
     private int totalPlayer;
 
     [Inject]
-    public NavigationManager NavigationManager { get; set; }
+    public required NavigationManager NavigationManager { get; set; }
 
     [CascadingParameter]
-    public IModalService Modal { get; set; }
+    public required IModalService Modal { get; set; }
 
     [Inject]
-    public IDataService DataService { get; set; }
-    public IWebHostEnvironment WebHostEnvironment { get; set; }
+    public required IDataService DataService { get; set; }
+    [Inject]
+    public required IWebHostEnvironment WebHostEnvironment { get; set; }
 
     [Inject]
-    public HttpClient Http { get; set; }
+    public required HttpClient Http { get; set; }
 
     [Inject]
-    public ILocalStorageService LocalStorage { get; set; }
+    public required ILocalStorageService LocalStorage { get; set; }
 
     [Inject]
-    public IJSRuntime IJSRuntime { get; set; }
+    public required IJSRuntime IJSRuntime { get; set; }
 
     private async void OnDelete(int id)
     {
diff --git a/Blazor/Blazor/Pages/Questions/AddQuestion.razor.cs b/Blazor/Blazor/Pages/Questions/AddQuestion.razor.cs
index 93906bd..25ec7f7 100644
--- a/Blazor/Blazor/Pages/Questions/AddQuestion.razor.cs
+++ b/Blazor/Blazor/Pages/Questions/AddQuestion.razor.cs
@@ -11,11 +11,11 @@ namespace Blazor.Pages.Questions
     {
         private QuestionModel questionModel = new();
 
-        public List<Chapter> chapters;
+        public List<Chapter> chapters = new();
 
-        private List<AnswerModel> answerModels;
+        private List<AnswerModel> answerModels = new();
         
-        public List<Checkbox> checkboxs;
+        public List<Checkbox> checkboxs = new();
 
         [Inject]
         public required IDataService DataService { get; set; }
@@ -24,10 +24,10 @@ namespace Blazor.Pages.Questions
         public required NavigationManager NavigationManager { get; set; }
 
         [Inject]
-        public HttpClient Http { get; set; }
+        public required HttpClient Http { get; set; }
 
         [Inject]
-        public ILogger<AddAdministrator> Logger { get; set; }
+        public required ILogger<AddAdministrator> Logger { get; set; }
         public class Checkbox
         {
             public int Id { get; set; }