feat:增加登录页

lib/services/webSocket_service.dart

@@ -0,0 +1,46 @@
+import 'dart:async';
+import 'package:web_socket_channel/web_socket_channel.dart';
+
+class WebSocketService {
+  static final WebSocketService _instance = WebSocketService._();
+
+  factory WebSocketService() => _instance;
+
+  WebSocketService._();
+
+  WebSocketChannel? _channel;
+
+  final _messageController = StreamController<String>.broadcast();
+  final _errorController = StreamController<Object>.broadcast();
+
+  Stream<String> get messages => _messageController.stream;
+
+  Stream<Object> get errors => _errorController.stream;
+
+  bool get isConnected => _channel != null;
+
+  void connect(String url) {
+    if (_channel != null) return;
+
+    _channel = WebSocketChannel.connect(Uri.parse(url));
+
+    _channel!.stream.listen(
+      (message) => _messageController.add(message.toString()),
+      onError: (error) => _errorController.add(error),
+      onDone: () => _errorController.add('WebSocket closed'),
+    );
+  }
+
+  void send(String message) {
+    if (_channel == null) {
+      _errorController.add('WebSocket not connected');
+      return;
+    }
+    _channel!.sink.add(message);
+  }
+
+  void disconnect() {
+    _channel?.sink.close();
+    _channel = null;
+  }
+}