experimental support for set new storage path on iOS

lib/pages/settings/app.dart

@@ -32,11 +32,16 @@ class _AppSettingsState extends State<AppSettings> {
           title: "Set New Storage Path".tl,
           actionTitle: "Set".tl,
           callback: () async {
-            if (App.isMobile) {
+            var result;
+            if (App.isAndroid) {
               context.showMessage(message: "Not supported".tl);
               return;
             }
-            var result = await selectDirectory();
+            else if (App.isIOS) {
+              result = await selectDirectoryIOS();
+            } else {
+              result = await selectDirectory();
+            }
             if (result == null) return;
             var loadingDialog = showLoadingDialog(
               App.rootContext,

lib/utils/io.dart

@@ -160,6 +160,22 @@ class DirectoryPicker {
   }
 }
 
+class IOSDirectoryPicker {
+  static const MethodChannel _channel = MethodChannel("venera/method_channel");
+
+  // 调用 iOS 目录选择方法
+  static Future<String?> selectDirectory() async {
+    try {
+      final String? path = await _channel.invokeMethod('selectDirectory');
+      return path;
+    } catch (e) {
+      print("Error selecting directory: $e");
+      // 返回报错信息
+      return e.toString();
+    }
+  }
+}
+
 Future<file_selector.XFile?> selectFile({required List<String> ext}) async {
   file_selector.XTypeGroup typeGroup = file_selector.XTypeGroup(
     label: 'files',
@@ -181,6 +197,11 @@ Future<String?> selectDirectory() async {
   return path;
 }
 
+// selectDirectoryIOS
+Future<String?> selectDirectoryIOS() async {
+  return IOSDirectoryPicker.selectDirectory();
+}
+
 Future<void> saveFile(
     {Uint8List? data, required String filename, File? file}) async {
   if (data == null && file == null) {