rangeerror（index）：无效值：有效值范围为空：从Firebase获取数据时抖动为0

Question

body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            StreamBuilder(
              stream: Firestore.instance.collection('scores').snapshots(),
              builder: (context, snapshot)
              {
                if(snapshot.hasData) return Text('Loading Data...');
                return Column(
                  children: <Widget>[
                    Text(snapshot.data.documents[0]['TeamOne']),
                    Text(snapshot.data.documents[0]['TeamTwo']),
                    Text(snapshot.data.documents[0]['toWin'].toString()),
                    Text(snapshot.data.documents[0]['runs'].toString()),
                    Text(snapshot.data.documents[0]['wickets'].toString()),
                    Text(snapshot.data.documents[0]['overs'].toString()),
                  ],
                );
              },

            )
          ],
        ),
      ),

我正在尝试从Firebase获取数据，但收到此错误。首先，它转到第一个return语句，并在一段时间后显示红色屏幕，并显示错误“ rangeerror（index）：无效值：有效值范围为空：0”

Answer 1

我认为您可以使用“！”。

if(!snapshot.hasData) return Text('Loading Data...');