diff --git a/.drone.yml b/.drone.yml
index 05bc48e..53d61fd 100755
--- a/.drone.yml
+++ b/.drone.yml
@@ -19,14 +19,15 @@ steps:
     commands:
       - cd Blazor/
       - dotnet restore Blazor.sln
-      - dotnet test Blazor.sln --no-restore
+      - dotnet sonarscanner begin /k:MuscuMaths /d:sonar.host.url=$${PLUGIN_SONAR_HOST} /d:sonar.login=$${PLUGIN_SONAR_TOKEN} 
+      - dotnet test Blazor.sln --logger trx --no-restore /p:CollectCoverage=true /p:CoverletOutputFormat=cobertura --collect "XPlat Code Coverage"
+      - reportgenerator -reports:"/coverage.cobertura.xml" -reporttypes:SonarQube -targetdir:"coveragereport" -verbosity:Verbose
+
     depends_on: [build]
 
   - name: code-analysis
     image: hub.codefirst.iut.uca.fr/marc.chevaldonne/codefirst-dronesonarplugin-dotnet7
     commands:
-      - echo $$PLUGIN_SONAR_TOKEN
-      - echo $$PLUGIN_SONAR_HOST
       - cd Blazor/
       - dotnet restore Blazor.sln
       - dotnet sonarscanner begin /k:MuscuMaths /d:sonar.host.url=$${PLUGIN_SONAR_HOST} /d:sonar.login=$${PLUGIN_SONAR_TOKEN} 
diff --git a/Blazor/Blazor/Components/DisplayQuestions.razor.cs b/Blazor/Blazor/Components/DisplayQuestions.razor.cs
index 91383e1..af7486b 100644
--- a/Blazor/Blazor/Components/DisplayQuestions.razor.cs
+++ b/Blazor/Blazor/Components/DisplayQuestions.razor.cs
@@ -15,10 +15,10 @@ namespace Blazor.Components
         public Question question = new();
 
         private List<Answer> answers = new();
-        public List<Question> questions;
+        public List<Question> questions = new();
 
         [Inject]
-        public HttpClient Http { get; set; }
+        public required HttpClient Http { get; set; }
 
         protected override async Task OnInitializedAsync()
         {
diff --git a/Blazor/Blazor/Modals/DeleteConfirmation.razor.cs b/Blazor/Blazor/Modals/DeleteConfirmation.razor.cs
index b6f8431..4ff91c2 100644
--- a/Blazor/Blazor/Modals/DeleteConfirmation.razor.cs
+++ b/Blazor/Blazor/Modals/DeleteConfirmation.razor.cs
@@ -9,22 +9,14 @@ namespace Blazor.Modals
     public partial class DeleteConfirmation
     {
         [CascadingParameter]
-        public BlazoredModalInstance ModalInstance { get; set; }
+        public required BlazoredModalInstance ModalInstance { get; set; }
 
         [Inject]
-        public IDataService DataService { get; set; }
+        public required IDataService DataService { get; set; }
 
         [Parameter]
         public int Id { get; set; }
 
-        //private Chapter chapter = new Chapter();
-
-        //protected override async Task OnInitializedAsync()
-     
-        //    // Get the chapter
-        //    chapter = await DataService.GetById(Id);
-        //}
-
         void ConfirmDelete()
         {
             ModalInstance.CloseAsync(ModalResult.Ok(true));
diff --git a/Blazor/Blazor/Models/AdministratorModel.cs b/Blazor/Blazor/Models/AdministratorModel.cs
index 89e5042..7331a39 100644
--- a/Blazor/Blazor/Models/AdministratorModel.cs
+++ b/Blazor/Blazor/Models/AdministratorModel.cs
@@ -8,8 +8,8 @@ namespace Blazor.Models;
 public class AdministratorModel 
 {
     public int Id { get; set; }
-    public string Username { get; set; }
-    public string HashedPassword { get; set; }
+    public required string Username { get; set; }
+    public required string HashedPassword { get; set; }
 
     public void HashPassword(string password)
     {
diff --git a/Blazor/Blazor/Models/AnswerModel.cs b/Blazor/Blazor/Models/AnswerModel.cs
index 2afbb19..6b59e83 100644
--- a/Blazor/Blazor/Models/AnswerModel.cs
+++ b/Blazor/Blazor/Models/AnswerModel.cs
@@ -4,8 +4,8 @@ public class AnswerModel
 
 {
     public int Id { get; set; }
-    public string Content { get; set; }
-    public int IdQuestion { get; set; }
+    public string? Content { get; set; }
+    public int? IdQuestion { get; set; }
     public AnswerModel(int id)
     {
         Id = id;
diff --git a/Blazor/Blazor/Models/ChapterModel.cs b/Blazor/Blazor/Models/ChapterModel.cs
index 44915a5..7a6d9bc 100644
--- a/Blazor/Blazor/Models/ChapterModel.cs
+++ b/Blazor/Blazor/Models/ChapterModel.cs
@@ -8,6 +8,6 @@ namespace Blazor.Models
 
         [Required(ErrorMessage = "Name is required")]
         [StringLength(50, ErrorMessage = "Name is too long.")]
-        public string Name { get; set; }
+        public required string Name { get; set; }
     }
 }
diff --git a/Blazor/Blazor/Models/PlayerModel.cs b/Blazor/Blazor/Models/PlayerModel.cs
index 43c37a0..84572aa 100644
--- a/Blazor/Blazor/Models/PlayerModel.cs
+++ b/Blazor/Blazor/Models/PlayerModel.cs
@@ -7,8 +7,8 @@ namespace Blazor.Models;
 public class PlayerModel
 {
     public int Id { get; set; }
-    public string Nickname { get; set; }
-    public string HashedPassword { get; set; }
+    public required string Nickname { get; set; }
+    public required string HashedPassword { get; set; }
 
     public void HashPassword(string password)
     {
diff --git a/Blazor/Blazor/Models/QuestionModel.cs b/Blazor/Blazor/Models/QuestionModel.cs
index ecdc5df..586a456 100644
--- a/Blazor/Blazor/Models/QuestionModel.cs
+++ b/Blazor/Blazor/Models/QuestionModel.cs
@@ -3,13 +3,12 @@
 public class QuestionModel
 {
     public int Id { get; set; }
-    public string Content { get; set; }
+    public required string Content { get; set; }
     public int IdChapter { get; set; }
-    public int? IdAnswerGood { get; set; }
+    public int IdAnswerGood { get; set; }
     public int Difficulty { get; set; }
     public int NbFails { get; set; }
 
-
     public void addFails(int nb) { NbFails += nb; }
     public void removeFails(int nb) { NbFails -= nb; }
 }
diff --git a/Blazor/Blazor/Pages/Admins/AddAdministrator.razor b/Blazor/Blazor/Pages/Admins/AddAdministrator.razor
index b198619..7742c74 100644
--- a/Blazor/Blazor/Pages/Admins/AddAdministrator.razor
+++ b/Blazor/Blazor/Pages/Admins/AddAdministrator.razor
@@ -2,7 +2,6 @@
 @using Blazor.Models
 
 <h3>AddAdministrator</h3>
-
 <EditForm Model="@administratorModel" OnValidSubmit="@HandleValidSubmit">
     <DataAnnotationsValidator />
     <ValidationSummary />
diff --git a/Blazor/Blazor/Pages/Admins/AddAdministrator.razor.cs b/Blazor/Blazor/Pages/Admins/AddAdministrator.razor.cs
index 23b3d6a..e73d03a 100644
--- a/Blazor/Blazor/Pages/Admins/AddAdministrator.razor.cs
+++ b/Blazor/Blazor/Pages/Admins/AddAdministrator.razor.cs
@@ -6,47 +6,50 @@ namespace Blazor.Pages.Admins
 {
     public partial class AddAdministrator
     {
-        private AdministratorModel administratorModel = new();
+        private AdministratorModel? administratorModel;
 
         [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()
         {
-            administratorModel.HashPassword(administratorModel.HashedPassword);
-
-            var formData = new List<KeyValuePair<string, string>>();
-            formData.Add(new KeyValuePair<string, string>("username", administratorModel.Username));
-            formData.Add(new KeyValuePair<string, string>("password", administratorModel.HashedPassword));
-
-            var formContent = new FormUrlEncodedContent(formData);
-
-            string apiUri = API.API_URL+"add/administrator/"+API.TOKEN;
-
-            using (var httpClient = new HttpClient())
-            {
-                var response = await httpClient.PostAsync(apiUri, formContent);
-
-                if (response.IsSuccessStatusCode)
-                {
-                    var responseBody = await response.Content.ReadAsStringAsync();
-                }
-                else
-                {
-                    var errorResponse = await response.Content.ReadAsStringAsync();
-                }
+            if (administratorModel != null)
+            {
+                administratorModel.HashPassword(administratorModel.HashedPassword);
+
+                var formData = new List<KeyValuePair<string, string>>();
+                formData.Add(new KeyValuePair<string, string>("username", administratorModel.Username));
+                formData.Add(new KeyValuePair<string, string>("password", administratorModel.HashedPassword));
+
+                var formContent = new FormUrlEncodedContent(formData);
+
+                string apiUri = API.API_URL + "add/administrator/" + API.TOKEN;
+
+                using (var httpClient = new HttpClient())
+                {
+                    var response = await httpClient.PostAsync(apiUri, formContent);
+
+                    if (response.IsSuccessStatusCode)
+                    {
+                        var responseBody = await response.Content.ReadAsStringAsync();
+                    }
+                    else
+                    {
+                        var errorResponse = await response.Content.ReadAsStringAsync();
+                    }
+                }
+
+                Logger.LogInformation("Admin '{administratorsModelName}' added", administratorModel.Username);
+
+                NavigationManager.NavigateTo("administrators");
             }
-
-            Logger.LogInformation("Admin '{administratorsModelName}' added", administratorModel.Username);
-
-            NavigationManager.NavigateTo("administrators");
         }
     }
 }
diff --git a/Blazor/Blazor/Pages/Admins/Administrators.razor.cs b/Blazor/Blazor/Pages/Admins/Administrators.razor.cs
index d99d06e..891f1f8 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)
     {
@@ -41,7 +41,7 @@ public partial class Administrators
 
         var response = Http.GetFromJsonAsync<Administrator[]>(API.API_URL+"administrators/"+API.TOKEN).Result;
 
-        if (!e.CancellationToken.IsCancellationRequested)
+        if (!e.CancellationToken.IsCancellationRequested && response != null)
         {
             administrators = new List<Administrator>(response); // an actual data for the current page
             totalItem = administrators.Count;
diff --git a/Blazor/Blazor/Pages/Admins/EditAdministrator.razor.cs b/Blazor/Blazor/Pages/Admins/EditAdministrator.razor.cs
index 3d91c64..c5fd294 100644
--- a/Blazor/Blazor/Pages/Admins/EditAdministrator.razor.cs
+++ b/Blazor/Blazor/Pages/Admins/EditAdministrator.razor.cs
@@ -10,21 +10,21 @@ namespace Blazor.Pages.Admins
         [Parameter]
         public int Id { get; set; }
 
-        private AdministratorModel administratorModel = new();
+        private AdministratorModel? administratorModel;
 
         [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()
         {
@@ -41,33 +41,36 @@ namespace Blazor.Pages.Admins
 
         private async Task HandleValidSubmit()
         {
-            administratorModel.HashPassword(administratorModel.HashedPassword);
-
-            var formData = new List<KeyValuePair<string, string>>();
-            formData.Add(new KeyValuePair<string, string>("username", administratorModel.Username));
-            formData.Add(new KeyValuePair<string, string>("password", administratorModel.HashedPassword));
-
-            var formContent = new FormUrlEncodedContent(formData);
-
-            string apiUri = API.API_URL+"update/administrator/" + administratorModel.Id + "/" + API.TOKEN;
-
-            using (var httpClient = new HttpClient())
-            {
-                var response = await httpClient.PostAsync(apiUri, formContent);
-
-                if (response.IsSuccessStatusCode)
-                {
-                    var responseBody = await response.Content.ReadAsStringAsync();
-                }
-                else
-                {
-                    var errorResponse = await response.Content.ReadAsStringAsync();
-                }
+            if (administratorModel != null)
+            {
+                administratorModel.HashPassword(administratorModel.HashedPassword);
+
+                var formData = new List<KeyValuePair<string, string>>();
+                formData.Add(new KeyValuePair<string, string>("username", administratorModel.Username));
+                formData.Add(new KeyValuePair<string, string>("password", administratorModel.HashedPassword));
+
+                var formContent = new FormUrlEncodedContent(formData);
+
+                string apiUri = API.API_URL + "update/administrator/" + administratorModel.Id + "/" + API.TOKEN;
+
+                using (var httpClient = new HttpClient())
+                {
+                    var response = await httpClient.PostAsync(apiUri, formContent);
+
+                    if (response.IsSuccessStatusCode)
+                    {
+                        var responseBody = await response.Content.ReadAsStringAsync();
+                    }
+                    else
+                    {
+                        var errorResponse = await response.Content.ReadAsStringAsync();
+                    }
+                }
+
+                Logger.LogInformation("Admin '{OldAdminModelName}' edited in '{NewAdminModelName}'", OldAdminName, administratorModel.Username);
+
+                NavigationManager.NavigateTo("administrators");
             }
-
-            Logger.LogInformation("Admin '{OldAdminModelName}' edited in '{NewAdminModelName}'",OldAdminName,administratorModel.Username);
-
-            NavigationManager.NavigateTo("administrators");
         }
     }
 }
diff --git a/Blazor/Blazor/Pages/Chapters/AddChapter.razor.cs b/Blazor/Blazor/Pages/Chapters/AddChapter.razor.cs
index 098045b..150dd2a 100644
--- a/Blazor/Blazor/Pages/Chapters/AddChapter.razor.cs
+++ b/Blazor/Blazor/Pages/Chapters/AddChapter.razor.cs
@@ -6,47 +6,49 @@ namespace Blazor.Pages.Chapters;
 
 public partial class AddChapter
 {
-    private ChapterModel chapterModel = new();
+    private ChapterModel? chapterModel;
 
     [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; }
 
 
 
     private async Task HandleValidSubmit()
     {
-        var formData = new List<KeyValuePair<string, string>>();
-        formData.Add(new KeyValuePair<string, string>("name", chapterModel.Name));
-
-
-        var formContent = new FormUrlEncodedContent(formData);
-
-        string apiUri = API.API_URL+"add/chapter/"+API.TOKEN;
-
-        using (var httpClient = new HttpClient())
-        {
-            var response = await httpClient.PostAsync(apiUri, formContent);
-
-            if (response.IsSuccessStatusCode)
-            {
-                var responseBody = await response.Content.ReadAsStringAsync();
-            }
-            else
-            {
-                var errorResponse = await response.Content.ReadAsStringAsync();
-            }
+        if (chapterModel != null)
+        {
+            var formData = new List<KeyValuePair<string, string>>();
+            formData.Add(new KeyValuePair<string, string>("name", chapterModel.Name));
+
+
+            var formContent = new FormUrlEncodedContent(formData);
+
+            string apiUri = API.API_URL + "add/chapter/" + API.TOKEN;
+
+            using (var httpClient = new HttpClient())
+            {
+                var response = await httpClient.PostAsync(apiUri, formContent);
+
+                if (response.IsSuccessStatusCode)
+                {
+                    var responseBody = await response.Content.ReadAsStringAsync();
+                }
+                else
+                {
+                    var errorResponse = await response.Content.ReadAsStringAsync();
+                }
+            }
+
+            Logger.LogInformation("Chapter '{chapterModelName}' added", chapterModel.Name);
+
+            NavigationManager.NavigateTo("chapters");
         }
-
-        Logger.LogInformation("Chapter '{chapterModelName}' added",chapterModel.Name);
-
-        NavigationManager.NavigateTo("chapters");
-
     }
 
 }
diff --git a/Blazor/Blazor/Pages/Chapters/EditChapter.razor.cs b/Blazor/Blazor/Pages/Chapters/EditChapter.razor.cs
index 17b71cd..c2dc0d2 100644
--- a/Blazor/Blazor/Pages/Chapters/EditChapter.razor.cs
+++ b/Blazor/Blazor/Pages/Chapters/EditChapter.razor.cs
@@ -9,7 +9,7 @@ public partial class EditChapter
     [Parameter]
     public int Id { get; set; }
 
-    private ChapterModel chapterModel = new();
+    private ChapterModel? chapterModel;
 
     [Inject]
     public IDataService DataService { get; set; }
diff --git a/Blazor/Blazor/Pages/Players/AddPlayer.razor.cs b/Blazor/Blazor/Pages/Players/AddPlayer.razor.cs
index e46e775..ffce2cc 100644
--- a/Blazor/Blazor/Pages/Players/AddPlayer.razor.cs
+++ b/Blazor/Blazor/Pages/Players/AddPlayer.razor.cs
@@ -6,41 +6,44 @@ namespace Blazor.Pages.Players
 {
     public partial class AddPlayer
     {
-        private PlayerModel playerModel = new();
+        private PlayerModel? playerModel;
 
         [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()
         {
-            playerModel.HashPassword(playerModel.HashedPassword);
-
-            var formData = new List<KeyValuePair<string, string>>();
-            formData.Add(new KeyValuePair<string, string>("nickname", playerModel.Nickname));
-            formData.Add(new KeyValuePair<string, string>("password", playerModel.HashedPassword));
+            if (playerModel != null)
+            {
+                playerModel.HashPassword(playerModel.HashedPassword);
 
-            var formContent = new FormUrlEncodedContent(formData);
+                var formData = new List<KeyValuePair<string, string>>();
+                formData.Add(new KeyValuePair<string, string>("nickname", playerModel.Nickname));
+                formData.Add(new KeyValuePair<string, string>("password", playerModel.HashedPassword));
 
-            string apiUri =API.API_URL+"add/player/"+API.TOKEN;
+                var formContent = new FormUrlEncodedContent(formData);
 
-            using (var httpClient = new HttpClient())
-            {
-                var response = await httpClient.PostAsync(apiUri, formContent);
+                string apiUri = API.API_URL + "add/player/" + API.TOKEN;
 
-                if (response.IsSuccessStatusCode)
-                {
-                    var responseBody = await response.Content.ReadAsStringAsync();
-                }
-                else
+                using (var httpClient = new HttpClient())
                 {
-                    var errorResponse = await response.Content.ReadAsStringAsync();
+                    var response = await httpClient.PostAsync(apiUri, formContent);
+
+                    if (response.IsSuccessStatusCode)
+                    {
+                        var responseBody = await response.Content.ReadAsStringAsync();
+                    }
+                    else
+                    {
+                        var errorResponse = await response.Content.ReadAsStringAsync();
+                    }
                 }
+                NavigationManager.NavigateTo("players");
             }
-            NavigationManager.NavigateTo("players");
         }
     }
 }
diff --git a/Blazor/Blazor/Pages/Players/EditPlayer.razor.cs b/Blazor/Blazor/Pages/Players/EditPlayer.razor.cs
index 1dd4d4a..515e8a6 100644
--- a/Blazor/Blazor/Pages/Players/EditPlayer.razor.cs
+++ b/Blazor/Blazor/Pages/Players/EditPlayer.razor.cs
@@ -10,16 +10,16 @@ namespace Blazor.Pages.Players
         [Parameter]
         public int Id { get; set; }
 
-        private PlayerModel playerModel = new();
+        private PlayerModel? playerModel;
 
         [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 7c5f149..b67ed9d 100644
--- a/Blazor/Blazor/Pages/Questions/AddQuestion.razor.cs
+++ b/Blazor/Blazor/Pages/Questions/AddQuestion.razor.cs
@@ -9,13 +9,13 @@ namespace Blazor.Pages.Questions
 {
     public partial class AddQuestion
     {
-        private QuestionModel questionModel = new();
+        private QuestionModel? questionModel;
 
-        public List<Chapter> chapters;
+        public List<Chapter> chapters = new();
 
-        private List<AnswerModel> answerModels;
+        private List<AnswerModel> answerModels = new();
         
-        private 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; }
@@ -50,10 +50,18 @@ namespace Blazor.Pages.Questions
                 checkboxs.Add(new Checkbox(i));
             }
         }
-        private async void HandleValidSubmit()
-        {
 
-            await DataService.Add(questionModel);
+        protected override async Task OnInitializedAsync()
+        {
+            var response = Http.GetFromJsonAsync<Chapter[]>(API.API_URL + "chapters/" + API.TOKEN).Result;
+            if (response == null) chapters = new List<Chapter>();
+            else chapters = new List<Chapter>(response);
+        }
+        private async Task HandleValidSubmit()
+        {
+            if (questionModel != null)
+            {
+                await DataService.Add(questionModel);
 
             var formData = new List<KeyValuePair<string, string>>();
             formData.Add(new KeyValuePair<string, string>("content", questionModel.Content));
@@ -75,23 +83,24 @@ namespace Blazor.Pages.Questions
              
             var formContent = new FormUrlEncodedContent(formData);
 
-            string apiUri = API.API_URL+"add/question/"+API.TOKEN;
+                string apiUri = API.API_URL + "add/question/" + API.TOKEN;
 
-            using (var httpClient = new HttpClient())
-            {
-                var response = await httpClient.PostAsync(apiUri, formContent);
-
-                if (response.IsSuccessStatusCode)
-                {
-                    var responseBody = await response.Content.ReadAsStringAsync();
-                }
-                else
+                using (var httpClient = new HttpClient())
                 {
-                    var errorResponse = await response.Content.ReadAsStringAsync();
+                    var response = await httpClient.PostAsync(apiUri, formContent);
+
+                    if (response.IsSuccessStatusCode)
+                    {
+                        var responseBody = await response.Content.ReadAsStringAsync();
+                    }
+                    else
+                    {
+                        var errorResponse = await response.Content.ReadAsStringAsync();
+                    }
                 }
-            }
 
-            NavigationManager.NavigateTo("questions");
+                NavigationManager.NavigateTo("questions");
+            }
         }
     }
 }
diff --git a/Blazor/Blazor/Pages/Questions/EditQuestion.razor.cs b/Blazor/Blazor/Pages/Questions/EditQuestion.razor.cs
index 50a0e94..948ce85 100644
--- a/Blazor/Blazor/Pages/Questions/EditQuestion.razor.cs
+++ b/Blazor/Blazor/Pages/Questions/EditQuestion.razor.cs
@@ -11,7 +11,7 @@ namespace Blazor.Pages.Questions
         [Parameter]
         public int Id { get; set; }
 
-        private QuestionModel questionModel = new();
+        private QuestionModel? questionModel;
 
         [Inject]
         public required IDataService DataService { get; set; }