我使用Flutter和Firebase来构建一个订单应用程序。我使用实时数据库和streambuilder来获取数据和每个更新，并使用listview.builder来描绘它们。
当我显示数据时，工作正常，但问题是当我尝试在RTDB中展开数据时，我会收到此错误
引发了另一个异常：范围错误（索引）：索引超出范围：索引应小于22：22.
我正试图在另一个页面上展开数据。如果我的问题是第一次问的有点废话，请原谅

Scaffold(
      body: StreamBuilder(
          stream: ref.onValue,
          builder: (context, snapshot) {
            if(
              snapshot.hasData &&
              snapshot.data != null &&
              (snapshot.data! as DatabaseEvent).snapshot.children !=
                  null){
              List<Orderlist> listorder = [];
              

              final myorders = snapshot.data!.snapshot.children;
              
              
              myorders.forEach((numoftable) {
                count+=1;
              
                String payment_state = '';
                String payment_method = '';
             
                List<Order> orders=[];

                  final number_of_orders = numoftable.children.length;

                  numoftable.children.forEach((order) {

                  if(order.key=='payment_state') payment_state=order.value.toString();
                  if(order.key=='payment_method') payment_method=order.value.toString();
                  
                  List<Orderitem> orderitems = [];
                  final order_id = order.key.toString();
                  // print(order_id);

                  

                  if(order_id.length<=3){
                    
                    final node = order.value as Map<dynamic,dynamic>?;

                    String temp_pending='';
                    String temp_payment='';
                    String customer_uid='';
                    node!.forEach((keys,values) {
                      // orderitem.name = element;
                      
                      if(keys!='description' && keys!='customer_uid'){
                        final value = values as Map<String,dynamic>;
                        String price='';
                        String description='';
                        String number_of_appereance='';
                        value.forEach((key, value) {
                          
                          if(key=='price') price=value.toString();
                          if(key=='description') description=value;
                          if(key=='number of appereances') number_of_appereance = value.toString();
                        });
                        final orderitem = Orderitem(name: keys,price: price,description: description,number_of_appereance: number_of_appereance);
                        orderitems.add(orderitem);
                      }
                      
                     if(keys=='description'){
                       temp_pending = values.toString();
                     }
                     if(keys=='customer_uid'){
                       customer_uid=values.toString();
                     }
                    
                     
                    },);
                    

                    final nextorder = Order(number_of_table: int.tryParse(numoftable.key.toString()),
                    items: orderitems,order_ids: order_id,customer_uid: customer_uid,
                    pending: temp_pending,);

                    
                    orders.add(nextorder);

                    
                    
                  }

                });
                final current_index = int.parse(numoftable.key.toString())-1;
                
                  
                `your text`
                   if(temp_length.isEmpty || count<=myorders.length){
                    
                     temp_length.insert(current_index, orders.length);
                    
                   }
                   else if(temp_length[current_index]<orders.length ){
                        
                        temp_length[current_index]= orders.length;
                        
                        ref.child(numoftable.key.toString()).update({'payment_state':'Not payed'});
                        ref.child(numoftable.key.toString()).update({'payment_method':'Cash'});
                    }
                    
                     
                    
                  final nextorderlist = Orderlist(
                    orderlist: orders,
                    number_of_table: numoftable.key.toString(),
                    payment_state: payment_state,
                    payment_method: payment_method,
                    number_of_orders: number_of_orders);
                  // print(nextorder.order_ids);
                  
                  listorder.add(nextorderlist);
                
                // ref.child(numoftable.key.toString()).update({'check':'false'});
              },
              
              );
              
              return Column(
                children: [
                  
                  GeneralSettings(),
                  Flexible(
                    child: GridView.builder(
                      shrinkWrap: true,
                      itemCount: listorder.length ,
                      gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(crossAxisCount: 3),
                      itemBuilder: (context, index) {
                        
                        
                        return _listoforders(listorder, index,);
                      },
                    ),
                  ),
                ],
              );
              
            }else if(snapshot.connectionState==ConnectionState.waiting){
              Center(child: CircularProgressIndicator(),);
            } 
            else if(snapshot.hasError){
              return Text('Error');
            }
            return Text('Error');
            
          }
          ),
    );
}
Widget _listoforders(List<Orderlist> listoforders,int index) {

  return GestureDetector(
  onTap: (){ 
    orders.clear();
    listoforders[index].orderlist!.forEach((element) { orders.add(element); });
    
    context.goNamed('Details');
    },
  child:   Container(
  
    color:listoforders[index].payment_state=='None' ? Colors.lightBlue : (listoforders[index].payment_state=='Not payed') ? Colors.red : Colors.green,
  
    child:   Column(
  
      children: [
        ListTile(title: Text(listoforders[index].number_of_table.toString()),
        subtitle: listoforders[index].payment_state=='None' ? Icon(Icons.no_food) : listoforders[index].payment_state=='Not payed' ? Icon(Icons.money_off) : Text('Payed'),
        trailing: IconButton(onPressed: () { 
          listoforders[index].orderlist!.forEach((element) { 
            setState(() {
            temp_length[index]=0;
            ref.child(listoforders[index].number_of_table.toString()).child(element.order_ids!).remove();
            ref.child(listoforders[index].number_of_table.toString()).update({'payment_state':'None'});
            ref.child(listoforders[index].number_of_table.toString()).update({'payment_method':'None'});
            delete(element.customer_uid!);
            });

          });
          
        }, icon: Icon(Icons.delete)),
        leading: (listoforders[index].payment_method=='None' ) ? Text('No payment method') : (listoforders[index].payment_method=='With card' )  ? Icon(Icons.credit_card) :  Icon(Icons.money_rounded),),

        Flexible(
          child: ListView.builder(
          
            physics: ClampingScrollPhysics(),
          
            shrinkWrap: true,
          
            itemCount: listoforders[index].orderlist!.length,
          
            itemBuilder: (context, current_index) {
          
             
          
            final current_order = listoforders[index].orderlist![current_index];
          
          
          
              return Container(
          
                color: current_order.pending=='Unchecked' ? Colors.red : (current_order.pending=='pending') ? Colors.amber : Colors.green,
          
                child: ListTile(
          
          
                  onTap: () => Navigator.push(context, MaterialPageRoute(builder: (context)=>OrderSettings(order: current_order))),
                  title: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(current_order.order_ids!),
                      
                    ],
                  ),
          
                  subtitle: Text(current_order.pending!),
          
                  trailing: current_order.pending=='Unchecked' ? IconButton(onPressed: () => setState(() {
          
                    ref.child(current_order.number_of_table.toString()).child(current_order.order_ids!).update({"description":"pending"});
          
                  }) , icon: Icon(Icons.alarm_add)) : 
          
                  current_order.pending=='pending' ? IconButton(onPressed: () => setState(() {
          
                    ref.child(current_order.number_of_table.toString()).child(current_order.order_ids!).update({"description":"Done"});
          
                  }) , icon: Icon(Icons.pending_actions)) : Icon(Icons.check),
                  leading: IconButton(onPressed:() {
                    
                    ref.child(current_order.number_of_table.toString()).child(current_order.order_ids!).remove();
                    } ,
                  icon:Icon(Icons.delete) ,),
          
                ),
          
              );
          

            },),
        ),
  
      ],
  
    ),
  
  ),
);}
}
Future delete(String uid) async{
  final doc = FirebaseFirestore.instance.collection('Customers').doc(uid);
  await doc.update({'order':''});
}

我正在更新此页面上的RTDB

class UpdatePanel extends StatefulWidget {
  String? name;
  bool check;
  int? tables;
  UpdatePanel({super.key,this.name,required this.check, this.tables});

  @override
  State<UpdatePanel> createState() => _UpdatePanelState();
}

class _UpdatePanelState extends State<UpdatePanel> {
  late DatabaseReference ref;
  TextEditingController namecontroller = TextEditingController();

  TextEditingController number_of_tables = TextEditingController();

  @override
  void initState() {
    // TODO: implement initState
    ref=FirebaseDatabase.instance.ref().child(widget.name!);

    super.initState();
  }
  @override
  Widget build(BuildContext context) {
    print(widget.name);
    print(widget.tables);
    Size size = MediaQuery.of(context).size;
    final futurefiles = FirebaseStorage.instance.ref().child('${widget.name}/');
    return AlertDialog(
      title: Text(widget.check? 'Update businness name':'Update tables number'),
      content: Container(
        height: size.height*0.3,
        child: SingleChildScrollView(
          child: Column(children: [
            widget.check ?
            Textwidget(controller: namecontroller, hinttext: 'Update name', labeltext: 'Name', icon: Icon(Icons.business_center), color: Colors.black) :
            Textwidget(controller: number_of_tables, hinttext: 'Update number of tables', labeltext: 'Number of tables', icon: Icon(Icons.table_bar), color: Colors.black),
            SizedBox(height: size.height*0.05,),
            ElevatedButton.icon(onPressed: () {
              
              setState(() {
               DatabaseManager(displayName: widget.name).settabledata(int.parse(number_of_tables.text.trim()));

                createQrcodes();
                resetRTDB();
                (context as Element).reassemble();
                Navigator.pop(context);
              });
              
            }, icon: Icon(Icons.update), label: Text('Update'))
          ]),
        ),
      ),
      actions: [
        OutlinedButton(onPressed: () => Navigator.pop(context), child: Text('Close'))
      ],
    );
  }

  void resetRTDB() async{
    for(int i=widget.tables!+1;i<=int.parse(number_of_tables.text.trim());i++){
     await ref.child('${i}').set({"payment_state":"None","payment_method":"None",});
    }
  }

  Future<Uint8List> toQrImageData(String text) async {
  try {
    final image = await QrPainter(
      data: text,
      version: QrVersions.auto,
      gapless: false,
      color: Colors.black,
      emptyColor: Colors.white,
    ).toImage(300);
    final a = await image.toByteData(format: ImageByteFormat.png);
    return  a!.buffer.asUint8List();
   

  } catch (e) {
    throw e;
  }
}

Future createQrcodes() async{
  
  for(int i=widget.tables!+1;i<=int.parse(number_of_tables.text.trim());i++){
    final path = '${widget.name!.trim()}/${i}';
  final ref = FirebaseStorage.instance.ref().child(path);

  final file = await toQrImageData(widget.name!.trim().toLowerCase()+' '+'${i}');

  ref.putData(file,SettableMetadata(contentType: 'image/png'));

  }
  }
}