Gestiti allegati nel form

SteUp.Maui/MainPage.xaml.cs

@@ -1,10 +1,59 @@
-namespace SteUp.Maui
+namespace SteUp.Maui;
+
+public partial class MainPage : ContentPage
 {
-    public partial class MainPage : ContentPage
+    private static readonly string AttachedDir =
+        Path.Combine(FileSystem.CacheDirectory, "attached");
+
+    private const string Prefix = "https://localfiles/attached/";
+
+    public MainPage()
     {
-        public MainPage()
-        {
-            InitializeComponent();
-        }
+        InitializeComponent();
+
+        Directory.CreateDirectory(AttachedDir);
+
+        BlazorWebView.WebResourceRequested += BlazorWebView_WebResourceRequested;
     }
-}
+
+    private static void BlazorWebView_WebResourceRequested(object? sender, WebViewWebResourceRequestedEventArgs e)
+    {
+        var uri = e.Uri.ToString();
+        if (string.IsNullOrWhiteSpace(uri) ||
+            !uri.StartsWith(Prefix, StringComparison.OrdinalIgnoreCase))
+            return;
+
+        var fileName = uri[Prefix.Length..];
+
+        fileName = fileName.Replace("\\", "/");
+        if (fileName.Contains("..") || fileName.Contains('/'))
+        {
+            e.Handled = true;
+            e.SetResponse(400, "Bad Request");
+            return;
+        }
+
+        var fullPath = Path.Combine(AttachedDir, fileName);
+
+        if (!File.Exists(fullPath))
+        {
+            e.Handled = true;
+            e.SetResponse(404, "Not Found");
+            return;
+        }
+
+        e.Handled = true;
+        e.SetResponse(200, "OK", GetContentType(fullPath), File.OpenRead(fullPath));
+    }
+
+    private static string GetContentType(string path)
+    {
+        return Path.GetExtension(path).ToLowerInvariant() switch
+        {
+            ".png" => "image/png",
+            ".jpg" or ".jpeg" => "image/jpeg",
+            ".webp" => "image/webp",
+            _ => "application/octet-stream"
+        };
+    }
+}