前端之家

  1. 首页
  2. 问答

如何将快照数据传递到Flutter浮动操作按钮？

• 问答

我正在构建一个从API获取数据的Flutter应用。

如何将快照数据从Flutter屏幕传递到小部件构建器上下文之外的浮动操作按钮？

然后，浮动按钮会将数据传递给PDF构建器函数。

这是我的代码。

@override       小部件build（BuildContext context）{         返回脚手架（                   appBar：AppBar（                             backgroundColor：Colors.blue，                             automaticImplyLeading：否，                             centerTitle：是的，

                        title: Text(widget.bill.billNumber.toString(),style: TextStyle(color: Colors.white)
                                    ),leading: IconButton(icon:Icon(Icons.arrow_back),onpressed:() =>

                        Navigator.of(context).pushAndRemoveUntil(
                          MaterialPageRoute(
                             builder: (context) =>
                               BillsScreen(table: widget.table)),(Route<dynamic> route) => false)
                        )
              ),body: SafeArea(
                child: Container(
                       child: 
                          StreamBuilder<SalesResponse>(
                              stream: salesBloc.subject.stream,builder: (context,Asyncsnapshot<SalesResponse> snapshot) {

                                     if (snapshot.hasData) {

            return  _buildSalesListWidget(snapshot.data);

                                     } 

                                     else if (snapshot.hasError) {

                                             return                   
                  _buildErrorWidget(snapshot.error);

                                     } 
                              },)
              ),),floatingactionButtonLocation:  FloatingactionButtonLocation.centerDocked,floatingactionButton: Padding(
                    padding: const EdgeInsets.all(8.0),child: Row(
                              mainAxisAlignment: MainAxisAlignment.spaceEvenly,children: <Widget>[

                                 FloatingactionButton(
                                    heroTag: 1,backgroundColor: Colors.yellow,onpressed: () {
                                        Printing.layoutPdf(onLayout:(format)=> 
                                           buildReceipt(widget.table,widget.bill,data.sales));
                                    },child: Icon(FontAwesomeIcons.print),],)    
    );    
  }

  Widget _buildSalesListWidget(SalesResponse data) {
          return ListView.builder(
                     itemCount: data.sales.length,itemBuilder: (context,index) {
                         return ListTile(
                                  title: Text(
                                              data.sales[index].item,style: TextStyle(
                                                         fontWeight: FontWeight.w500,fontSize: 20,subtitle: Text('qty' + ' ' + data.sales[index].qty.toString() + ',' + 'price' + ' ' + data.sales[index].price.toStringAsFixed(2)),leading: Icon(
                                                FontAwesomeIcons.beer,color: Colors.blue[500],onTap: () {},);
                     },);

  }
}
sarah928 回答：如何将快照数据传递到Flutter浮动操作按钮？
class Screen extends StatefulWidget {
  @override
  _ScreenState createState() => _ScreenState();
}

class _ScreenState extends State<Screen> {

  String snapshotData = "";

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: FutureBuilder(
          future: Future.delayed(const Duration(seconds: 1),() => "data to pass"),builder: (context,AsyncSnapshot<String> snapshot) {
            if(!snapshot.hasData) {
             return Text("NO Data");
            } else {
              snapshotData = snapshot.data;
              return Text("Data loaded");
            }
          },),floatingActionButton: FloatingActionButton(
        onPressed: () => print(snapshotData),);
  }
}
flutter
本文链接：https://www.f2er.com/3164134.html

大家都在问