Persist last-used dialog folders in user preferences

Dialogs now remember last-used folders for source, destination, logo, and settings files by storing these paths in a user preferences file under LocalApplicationData. Preferences are saved on form close, reducing unnecessary writes. SettingsService now uses a temporary ParametriSetup for settings files to avoid polluting user preferences. Error handling ensures preference save failures do not disrupt the user. This separation improves user experience and keeps user preferences distinct from project settings.

imagecatalog/MainForm.cs

@@ -48,6 +48,9 @@ public partial class MainForm
         
         BindControls();
 
+        // Save user preferences on form close instead of immediately when dialogs are used
+        this.FormClosing += MainForm_FormClosing;
+
         // Wire up 'Open folder in Explorer' buttons
         btnOpenSourceFolder.Click += BtnOpenSourceFolder_Click;
         btnOpenDestFolder.Click += BtnOpenDestFolder_Click;
@@ -194,10 +197,17 @@ public partial class MainForm
 
     private void OnSelectSourceFolderRequested(object sender, EventArgs e)
     {
-        var dialogResult = SelectFolder(Model.SourcePath);
+        // Prefer model value; if empty fall back to last-used value stored in user prefs
+        var starting = !string.IsNullOrWhiteSpace(Model.SourcePath)
+            ? Model.SourcePath
+            : _parametriSetup.LeggiParametroString("LastSourceFolder");
+
+        var dialogResult = SelectFolder(starting);
         if (!string.IsNullOrWhiteSpace(dialogResult))
         {
             Model.SourcePath = dialogResult;
+            _parametriSetup.AggiornaParametro("LastSourceFolder", dialogResult);
+            _parametriSetup.SalvaParametriSetup();
         }
     }
 
@@ -254,10 +264,16 @@ public partial class MainForm
 
     private void OnSelectDestinationFolderRequested(object sender, EventArgs e)
     {
-        var dialogResult = SelectFolder(Model.DestinationPath);
+        var starting = !string.IsNullOrWhiteSpace(Model.DestinationPath)
+            ? Model.DestinationPath
+            : _parametriSetup.LeggiParametroString("LastDestinationFolder");
+
+        var dialogResult = SelectFolder(starting);
         if (!string.IsNullOrWhiteSpace(dialogResult))
         {
             Model.DestinationPath = dialogResult;
+            _parametriSetup.AggiornaParametro("LastDestinationFolder", dialogResult);
+            _parametriSetup.SalvaParametriSetup();
         }
     }
 
@@ -265,15 +281,36 @@ public partial class MainForm
     {
         var dialog = new OpenFileDialog();
         dialog.Filter = "Image Files|*.jpg;*.jpeg;*.png;*.bmp;*.gif";
-        if (Model.LogoFile.Length > 0)
+        if (!string.IsNullOrWhiteSpace(Model.LogoFile))
         {
             dialog.FileName = Model.LogoFile;
         }
+        else
+        {
+            var lastLogoFolder = _parametriSetup.LeggiParametroString("LastLogoFolder");
+            if (!string.IsNullOrWhiteSpace(lastLogoFolder) && Directory.Exists(lastLogoFolder))
+            {
+                dialog.InitialDirectory = lastLogoFolder;
+            }
+        }
         
         if (dialog.ShowDialog() == DialogResult.OK)
         {
             Model.LogoFile = dialog.FileName;
             UpdateLogoPictureBox(Model.LogoFile);
+            try
+            {
+                var folder = Path.GetDirectoryName(dialog.FileName) ?? string.Empty;
+                if (!string.IsNullOrWhiteSpace(folder))
+                {
+                    _parametriSetup.AggiornaParametro("LastLogoFolder", folder);
+                    _parametriSetup.SalvaParametriSetup();
+                }
+            }
+            catch
+            {
+                // ignore preferences save failures
+            }
         }
     }
 
@@ -285,11 +322,28 @@ public partial class MainForm
             FilterIndex = 0,
             RestoreDirectory = true
         };
+        var lastSettings = _parametriSetup.LeggiParametroString("LastSettingsFolder");
+        if (!string.IsNullOrWhiteSpace(lastSettings) && Directory.Exists(lastSettings))
+            saveDialog.InitialDirectory = lastSettings;
 
         if (saveDialog.ShowDialog() != DialogResult.OK) return;
 
         await Model.SaveSettingsToFileAsync(saveDialog.FileName);
         Text = "Image Catalog - " + Path.GetFileName(saveDialog.FileName);
+
+        try
+        {
+            var folder = Path.GetDirectoryName(saveDialog.FileName) ?? string.Empty;
+            if (!string.IsNullOrWhiteSpace(folder))
+            {
+                _parametriSetup.AggiornaParametro("LastSettingsFolder", folder);
+                _parametriSetup.SalvaParametriSetup();
+            }
+        }
+        catch
+        {
+            // ignore
+        }
     }
 
     private async void OnLoadSettingsRequested(object sender, string e)
@@ -301,6 +355,10 @@ public partial class MainForm
             RestoreDirectory = true
         };
 
+        var lastSettings = _parametriSetup.LeggiParametroString("LastSettingsFolder");
+        if (!string.IsNullOrWhiteSpace(lastSettings) && Directory.Exists(lastSettings))
+            openDialog.InitialDirectory = lastSettings;
+
         if (openDialog.ShowDialog() != DialogResult.OK) return;
 
         try
@@ -318,6 +376,20 @@ public partial class MainForm
 
             Text = "Image Catalog - " + Path.GetFileName(openDialog.FileName);
             
+            try
+            {
+                var folder = Path.GetDirectoryName(openDialog.FileName) ?? string.Empty;
+                if (!string.IsNullOrWhiteSpace(folder))
+                {
+                    _parametriSetup.AggiornaParametro("LastSettingsFolder", folder);
+                    _parametriSetup.SalvaParametriSetup();
+                }
+            }
+            catch
+            {
+                // ignore preferences save failures
+            }
+
             _logger.LogInformation($"Settings loaded successfully from {openDialog.FileName}");
         }
         catch (Exception ex)
@@ -327,6 +399,24 @@ public partial class MainForm
         }
     }
 
+    private void MainForm_FormClosing(object? sender, FormClosingEventArgs e)
+    {
+        try
+        {
+            // Persist last-used dialogs paths (user preferences)
+            // These keys are managed independently from settings files
+            // and must be saved when the form closes.
+            _parametriSetup.AggiornaParametro("LastSourceFolder", Model.SourcePath ?? string.Empty);
+            _parametriSetup.AggiornaParametro("LastDestinationFolder", Model.DestinationPath ?? string.Empty);
+            _parametriSetup.AggiornaParametro("LastLogoFolder", Path.GetDirectoryName(Model.LogoFile ?? string.Empty) ?? string.Empty);
+            _parametriSetup.SalvaParametriSetup();
+        }
+        catch (Exception ex)
+        {
+            _logger?.LogWarning(ex, "Failed to save user preferences on exit");
+        }
+    }
+
     private void OnSelectColorRequested(object sender, EventArgs e)
     {
         var colorDialog = new ColorDialog

imagecatalog/Program.cs

@@ -92,7 +92,10 @@ static class Program
         services.AddTransient<ImageCreationStuff>();
         services.AddTransient<ImageCreatorSharp>();
 
-        services.AddSingleton<ParametriSetup>();
+        // Register a ParametriSetup singleton that persists user preferences in LocalApplicationData
+        var userPrefsPath = System.IO.Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData),
+            "ImageCatalog", "userprefs.xml");
+        services.AddSingleton(new ParametriSetup(userPrefsPath));
         services.AddSingleton<PicSettings>();
             
         // Register your forms

imagecatalog/Services/SettingsService.cs

@@ -24,9 +24,11 @@ namespace ImageCatalog_2.Services
 
         public Task SaveSettingsAsync(string filePath, object settings)
         {
+            // Use a dedicated ParametriSetup instance for the target settings file so the injected
+            // user preferences store is not modified. This keeps user prefs (singleton) intact.
             return Task.Run(() =>
             {
-                _parametriSetup.NomeFileSetup = filePath;
+                var fileParams = new ParametriSetup(filePath);
 
                 // Convert ViewModel to DTO
                 var dto = ViewModelToDto(settings);
@@ -36,28 +38,27 @@ namespace ImageCatalog_2.Services
 
                 foreach (var prop in properties)
                 {
-                    // Get the XmlElement attribute to determine the XML property name
                     var xmlAttr = prop.GetCustomAttribute<XmlElementAttribute>();
                     if (xmlAttr == null)
-                        continue; // Skip properties without XmlElement attribute
+                        continue;
 
                     var xmlName = xmlAttr.ElementName;
                     var value = prop.GetValue(dto);
 
-                    _parametriSetup.AggiornaParametro(xmlName, value);
+                    fileParams.AggiornaParametro(xmlName, value);
                 }
 
-                _parametriSetup.SalvaParametriSetup();
+                fileParams.SalvaParametriSetup();
             });
         }
 
         public async Task LoadSettingsAsync(string filePath, object settings)
         {
-            // Step 1: Load XML and read into DTO on background thread
+            // Step 1: Load XML into a temporary ParametriSetup so we don't mutate the injected
+            // user-preferences instance (singleton).
             var dto = await Task.Run(() =>
             {
-                _parametriSetup.NomeFileSetup = filePath;
+                var fileParams = new ParametriSetup(filePath);
-                _parametriSetup.CaricaParametriSetup();
 
                 var loadedDto = new SettingsDto();
                 var properties = typeof(SettingsDto).GetProperties(BindingFlags.Public | BindingFlags.Instance);
@@ -76,11 +77,11 @@ namespace ImageCatalog_2.Services
                         object value;
                         if (prop.PropertyType == typeof(string))
                         {
-                            value = _parametriSetup.LeggiParametroString(xmlName);
+                            value = fileParams.LeggiParametroString(xmlName);
                         }
                         else if (prop.PropertyType == typeof(bool))
                         {
-                            value = _parametriSetup.LeggiParametroBoolean(xmlName);
+                            value = fileParams.LeggiParametroBoolean(xmlName);
                         }
                         else if (prop.PropertyType == typeof(int))
                         {