firebase - 我如何添加加载圆形图标，因为从Firestore提取数据需要时间？

Question

I want to show a loading button until it loads all the list items from firestore.

return StreamBuilder(
         
        stream: Firestore.instance.collection(uid).snapshots(),
        
        builder: (context, snapshot) {
          if (snapshot.hasData) {
          
          return ListView.builder(
            itemBuilder: (ctx, index) {
              return FavItem(
                uid: snapshot.data.documents[index]['uid'],
                id: snapshot.data.documents[index]['id'],
         , 
                
                
              );
            },
            itemCount: snapshot.data.documents.length,
          

Answer 1

CircularProgressIndicator可能就是您想要的。

StreamBuilder(
      stream: Firestore.instance.collection(uid).snapshots(),
      builder: (context, snapshot) {
        if (snapshot.hasData) {
          return ...;
        }
        if (snapshot.hasError) {
          return Text(snapshot.error.toString());
        }
        return CircularProgressIndicator();
      },
    );