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颤振错误:位置参数太多:应为0,但在streambuilder中找到1

flutter-layout dart flutter

-1

nita makavana · 技术社区 · 2 年前

颤振错误:位置参数太多:应为0,但在streambuilder中发现1。我看过许多文章对此进行了发布,但我无法获得正确的解决方案,因此请帮助我解决此问题。

代码:

 StreamBuilder(
 stream: _products.snapshots(), //build connection
 builder: (context, AsyncSnapshot<QuerySnapshot> streamSnapshot) {
 if (streamSnapshot.hasData) {
 return ListView.builder(
 itemCount: streamSnapshot.data!.docs.length, //number of rows
 itemBuilder: (context, index) {
 final DocumentSnapshot documentSnapshot =
 streamSnapshot.data!.docs[index];
 return Card(
 margin: const EdgeInsets.all(10),
 child: ListTile(
 title: Text(documentSnapshot['name']),
 subtitle: Text(documentSnapshot['price'].toString()),
Â  Â  Â  Â  Â  Â  Â  Â  Â  ),
Â  Â  Â  Â  Â  Â  Â  Â  );
Â  Â  Â  Â  Â  Â  Â  },
Â  Â  Â  Â  Â  Â  );
Â  Â  Â  Â  Â  }

 return const Center(
 child: CircularProgressIndicator(),
Â  Â  Â  Â  Â  );
Â  Â  Â  Â  },
Â  Â  Â  )

enter image description here

1 回复 | 直到 2 年前

Kaushik Chandru 2 年前

流生成器看起来不在小部件树中。请试试这个

Scaffold(
floatingActionButton : FloatingActionButton(),
body : SizedBox(
        width: double.infinity,
        child: Center(
          child: StreamBuilder(
            stream: _products.snapshots(),
            initialData: 0,
            builder: (
                BuildContext context,
                AsyncSnapshot<QuerySnapshot> snapshot,
                ) {
              if (snapshot.connectionState == ConnectionState.waiting) {
                return Container( );
              } else if (snapshot.connectionState == ConnectionState.active
                  || snapshot.connectionState == ConnectionState.done) {
                if (snapshot.hasError) {
                  return const Text('Error');
                } else if (snapshot.hasData) {
                  return Text(
                      snapshot.data.toString(),
                  );
                } else {
                  return const Text('Empty data');
                }
              } else {
                return Text('State: ${snapshot.connectionState}');
              }
),

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