rangeerror（索引）：无效值：有效值范围为空：flutter 从 firebase 获取数据时为 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()),
                  ],
                );
              },

            )
          ],
        ),
      ),

I'm trying to get data from firebase but getting this error. first it goes to the first return statement and after some time it shows the red screen with error "rangeerror (index): invalid value: valid value range is empty: 0"

Answer 1

I think you can use ".".

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