小编Nin*_*udj的帖子

使用 FutureBuilder，我收到以下错误。

错误：参数类型“AsyncSnapshot”无法分配给参数类型“Position”。
指向线：return Map(snapshot);

错误：必须返回非空值，因为返回类型“Widget”不允许为空。指向行：构建器：（上下文，快照）

主页.dart

 Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: FittedBox(
            child: Text('something something'),
          ),
          actions: <Widget>[
           //irrelevant code for buttons etc

        ],
   body: FutureBuilder <Position> (
        future: _geolocatorService.getInitialLocation(),
        builder: (BuildContext context, snapshot) {

              if (snapshot.hasData) {   //<- can confirm snapshot has data and can display it 
                                        //  printed in terminal ex.: lat value, long, 
                                        // null,null
                                             
              print(snapshot);
              return Map(snapshot);    //<-having trouble passing snapshot data as Position to 
                                       //  this map
               }
              }
         ), …