修改地图卡片

lib/modules/chat/views/chat_navigation_card.dart

@@ -20,10 +20,12 @@ class _ChatNavigationCardState extends State<ChatNavigationCard> {
   LatLng startPoint = LatLng(116.397428, 39.90923); // 起点坐标
   LatLng endPoint = LatLng(116.397026, 39.903303); // 终点坐标
 
+  late Future _mapUrl;
+
   @override
   void initState() {
     super.initState();
-    _getMapUrl();
+    _mapUrl = _getMapUrl();
   }
 
   Future<String> _getMapUrl() async {
@@ -158,7 +160,7 @@ class _ChatNavigationCardState extends State<ChatNavigationCard> {
     return Column(
       children: [
         FutureBuilder(
-          future: _getMapUrl(),
+          future: _mapUrl,
           builder: (BuildContext context, AsyncSnapshot snapshot) {
             if (snapshot.hasData) {
               return Image.network(snapshot.data);