Resolving warnings and treating warnings as errors in WinUI project. (#824)

Wino.Mail.WinUI/Dialogs/AccountCreationDialog.xaml.cs

@@ -10,7 +10,7 @@ namespace Wino.Dialogs;
 public sealed partial class AccountCreationDialog : ContentDialog, IAccountCreationDialog
 {
     private TaskCompletionSource<bool> dialogOpened = new TaskCompletionSource<bool>();
-    public CancellationTokenSource CancellationTokenSource { get; private set; }
+    public CancellationTokenSource? CancellationTokenSource { get; private set; }
 
     public AccountCreationDialogState State
     {
@@ -41,7 +41,7 @@ public sealed partial class AccountCreationDialog : ContentDialog, IAccountCreat
         // Unregister from closing event.
         Closing -= DialogClosing;
 
-        if (cancel && !CancellationTokenSource.IsCancellationRequested)
+        if (cancel && CancellationTokenSource != null && !CancellationTokenSource.IsCancellationRequested)
         {
             CancellationTokenSource.Cancel();
         }

Wino.Mail.WinUI/Dialogs/AccountPickerDialog.xaml.cs

@@ -6,9 +6,9 @@ namespace Wino.Dialogs;
 
 public sealed partial class AccountPickerDialog : ContentDialog
 {
-    public MailAccount PickedAccount { get; set; }
+    public MailAccount? PickedAccount { get; set; }
 
-    public List<MailAccount> AvailableAccounts { get; set; }
+    public List<MailAccount> AvailableAccounts { get; set; } = [];
 
     public AccountPickerDialog(List<MailAccount> availableAccounts)
     {

Wino.Mail.WinUI/Dialogs/CustomThemeBuilderDialog.xaml.cs

@@ -10,21 +10,21 @@ namespace Wino.Dialogs;
 
 public sealed partial class CustomThemeBuilderDialog : ContentDialog
 {
-    public byte[] WallpaperData { get; private set; }
-    public string AccentColor { get; private set; }
+    public byte[] WallpaperData { get; private set; } = Array.Empty<byte>();
+    public string AccentColor { get; private set; } = string.Empty;
 
-    private INewThemeService _themeService;
+    private readonly INewThemeService _themeService;
 
     public CustomThemeBuilderDialog()
     {
         InitializeComponent();
 
-        _themeService = WinoApplication.Current.Services.GetService<INewThemeService>();
+        _themeService = WinoApplication.Current.Services.GetRequiredService<INewThemeService>();
     }
 
     private async void ApplyClicked(ContentDialog sender, ContentDialogButtonClickEventArgs args)
     {
-        if (Array.Empty<byte>() == WallpaperData)
+        if (WallpaperData.Length == 0)
             return;
 
         var deferal = args.GetDeferral();
@@ -45,11 +45,11 @@ public sealed partial class CustomThemeBuilderDialog : ContentDialog
 
     private async void BrowseWallpaperClicked(object sender, Microsoft.UI.Xaml.RoutedEventArgs e)
     {
-        var dialogService = WinoApplication.Current.Services.GetService<IMailDialogService>();
+        var dialogService = WinoApplication.Current.Services.GetRequiredService<IMailDialogService>();
 
         var pickedFileData = await dialogService.PickWindowsFileContentAsync(".jpg", ".png");
 
-        if (pickedFileData == Array.Empty<byte>()) return;
+        if (pickedFileData.Length == 0) return;
 
         IsPrimaryButtonEnabled = true;
 

Wino.Mail.WinUI/Dialogs/NewAccountDialog.xaml.cs

@@ -15,7 +15,7 @@ namespace Wino.Mail.WinUI.Dialogs;
 
 public sealed partial class NewAccountDialog : ContentDialog
 {
-    private Dictionary<SpecialImapProvider, string> helpingLinks = new Dictionary<SpecialImapProvider, string>()
+    private readonly Dictionary<SpecialImapProvider, string> helpingLinks = new Dictionary<SpecialImapProvider, string>()
     {
         { SpecialImapProvider.iCloud, "https://support.apple.com/en-us/102654" },
         { SpecialImapProvider.Yahoo, "http://help.yahoo.com/kb/SLN15241.html" },
@@ -28,9 +28,9 @@ public sealed partial class NewAccountDialog : ContentDialog
     public static readonly DependencyProperty SelectedCalendarModeIndexProperty = DependencyProperty.Register(nameof(SelectedCalendarModeIndex), typeof(int), typeof(NewAccountDialog), new PropertyMetadata(0));
 
 
-    public AppColorViewModel SelectedColor
+    public AppColorViewModel? SelectedColor
     {
-        get { return (AppColorViewModel)GetValue(SelectedColorProperty); }
+        get { return (AppColorViewModel?)GetValue(SelectedColorProperty); }
         set { SetValue(SelectedColorProperty, value); }
     }
 
@@ -43,9 +43,9 @@ public sealed partial class NewAccountDialog : ContentDialog
     /// <summary>
     /// Gets or sets current selected mail provider in the dialog.
     /// </summary>
-    public ProviderDetail SelectedMailProvider
+    public ProviderDetail? SelectedMailProvider
     {
-        get { return (ProviderDetail)GetValue(SelectedMailProviderProperty); }
+        get { return (ProviderDetail?)GetValue(SelectedMailProviderProperty); }
         set { SetValue(SelectedMailProviderProperty, value); }
     }
 
@@ -64,9 +64,9 @@ public sealed partial class NewAccountDialog : ContentDialog
 
     // List of available mail providers for now.
 
-    public List<IProviderDetail> Providers { get; set; }
+    public List<IProviderDetail> Providers { get; set; } = [];
 
-    public List<AppColorViewModel> AvailableColors { get; set; }
+    public List<AppColorViewModel> AvailableColors { get; set; } = [];
     public List<string> CalendarModeOptions { get; } =
     [
         Translator.ImapCalDavSettingsPage_CalendarModeCalDav,
@@ -75,7 +75,7 @@ public sealed partial class NewAccountDialog : ContentDialog
     ];
 
 
-    public AccountCreationDialogResult Result = null;
+    public AccountCreationDialogResult? Result = null;
 
     public NewAccountDialog()
     {
@@ -113,6 +113,9 @@ public sealed partial class NewAccountDialog : ContentDialog
 
     private void CreateClicked(ContentDialog sender, ContentDialogButtonClickEventArgs args)
     {
+        if (SelectedMailProvider == null)
+            return;
+
         if (IsSpecialImapServerPartVisible)
         {
             // Special imap detail input.
@@ -198,7 +201,11 @@ public sealed partial class NewAccountDialog : ContentDialog
 
     private async void AppSpecificHelpButtonClicked(object sender, RoutedEventArgs e)
     {
-        var helpUrl = helpingLinks[SelectedMailProvider.SpecialImapProvider];
+        if (SelectedMailProvider == null ||
+            !helpingLinks.TryGetValue(SelectedMailProvider.SpecialImapProvider, out var helpUrl))
+        {
+            return;
+        }
 
         await Launcher.LaunchUriAsync(new Uri(helpUrl));
     }

Wino.Mail.WinUI/Dialogs/PrintDialog.xaml.cs

@@ -25,7 +25,7 @@ public sealed partial class PrintDialog : ContentDialog
     /// Initializes the dialog with existing print settings.
     /// </summary>
     /// <param name="printSettings">The initial print settings to load.</param>
-    public PrintDialog(WebView2PrintSettingsModel printSettings = null)
+    public PrintDialog(WebView2PrintSettingsModel printSettings = default!)
     {
         if (printSettings != null) PrintSettings = printSettings;