如何使拍打得好？

如何解决如何使拍打得好？

我正在构建需要精简的Flutter应用程序。但是，它不能正常工作。当我添加一个项目时，该项目直到我离开并返回屏幕时才显示，并且删除完全不起作用。

这是页面的代码。

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:gestao_financeira_app/DatabaseConnections/DAO_Objects/ClassesDAO.dart';
import 'package:gestao_financeira_app/Models/Config/ClassesModel.dart';
import '../MenuScaffold/MenuScaffold.dart';
import 'package:flutter_masked_text/flutter_masked_text.dart';
import 'package:flutter/material.dart';

class ClassesConfig extends StatefulWidget {
  ClassesGeneral createState() => ClassesGeneral();
}

class ClassesGeneral extends State<ClassesConfig> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Configuração de Classes"),backgroundColor: Colors.purple[300],),persistentFooterButtons: <Widget>[BotaoAdd()],body:
          Container(padding: EdgeInsets.all(10.0),child: TelaConfigClasses()),drawer: MenuScaffold(),backgroundColor: Colors.grey[300],);
  }
}

class TelaConfigClasses extends StatelessWidget {
  @override
  var controller = new MoneyMaskedTextController(
      decimalSeparator: ',',thousandSeparator: '.');

  var fonteLocal = TextStyle(fontSize: 30);

  //var teste = new ClassesModel(id: 1,nome_classe: "null",tipo_classe: "Despesa");

  Widget build(BuildContext context) {
    return ListView(
      children: <Widget>[
        Text(
          "Classes de Rendas",style: fonteLocal,Container(
          height: MediaQuery.of(context).size.height * 0.60,child: ItensLista(),decoration: BoxDecoration(
            borderRadius: BorderRadius.circular(15),color: Colors.white,Container(height: 10),Text(
          "Classes de Despesas",],);
  }
}

class BotaoAdd extends StatelessWidget {
  @override
  var teste = new ClassesModel(
      id_entry: 55855,nome_classe: "Classe",tipo_classe: "Renda");

  Widget build(BuildContext context) {
    // TODO: implement build
    return ButtonTheme(
      height: MediaQuery.of(context).size.height * 0.08,minWidth: MediaQuery.of(context).size.height * 1,child: RaisedButton(
        color: Colors.purple[300],onPressed: () {
          print(teste);
          ClassesDAO().insertClass(teste);
          //ItensLista().build(context);
        },child: RichText(
          text: TextSpan(
            children: [
              TextSpan(
                  text: 'Adicionar Classe ',style: TextStyle(color: Colors.white,fontSize: 20)),WidgetSpan(
                child: Icon(
                  Icons.add,);
  }
}

class ItensLista extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return FutureBuilder<dynamic>(
      future: ClassesDAO().getAllClasses(),builder: (context,snapshot) {
        if (snapshot.connectionState == ConnectionState.done) {
          //print("valor total = "+valFin.toString());
          var objeto = [];

          for (var i in snapshot.data) {
            objeto.add(i);
          }

          return ListView.builder(
            itemCount: objeto.length,itemBuilder: (context,index) {
              return ListTile(
                title: Text(objeto[index].toString()),trailing: RaisedButton(
                  child: Text("delete"),onPressed: () {
                    print("TEste");
                    var X = new ClassesDAO().delete(objeto[index]);
                    new ItensLista().build(context);
                    print("TEste");
                    print(X);
                  },onTap: () async {
                  ClassesDAO().delete(objeto[index]);
                },onLongPress: () {},);
            },);
        } else if (snapshot.hasError) {
          throw snapshot.error;
        } else {
          return Center(child: CircularProgressIndicator());
        }
      },);
  }
}

，这是目前正在使用的应用的小视频 https://drive.google.com/file/d/1NgMzOe_o-dJoHd73nqYjg8x3_ppZf8SZ/view?usp=sharing