Flutter Provider 所有 Widget 重建问题

如何解决Flutter Provider 所有 Widget 重建问题

在我使用 SignalR 和 Provider 的项目中，我使用 signalR 拉取数据。我可以在调试模式和模拟器中看到它。我是新来的

我的问题是，在应用程序中，我可以立即通过 Provider 监听更改，相关小部件会重建整个页面，而不是重建它。

如何让它重建只有数据在监听的小部件。

我的视图模型、视图和小部件代码如下。

我是 flutter 的新手，所以如果您有任何遗漏，我将不胜感激。

主页代码：

import 'package:cobasys_mobile/pages/drawer_menu.dart';
import 'package:cobasys_mobile/viewmodel/santral_viewmodel.dart';
import 'package:cobasys_mobile/viewmodel/user_viewmodel.dart';
import 'package:cobasys_mobile/widgets/ozet_kutu_widget.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    debugPrint("HomePage rebuild");

    return Scaffold(
      appBar: AppBar(
        title: Text("Giriş"),actions: [
          TextButton(
            onPressed: () => _cikisYap(context),child: Text(
              "Çıkış Yap",style: TextStyle(color: Colors.white),),],drawer: MainDrawer(),body: Column(
        children: [
          Text(
            "Günlük Özet Bilgiler",style: TextStyle(
              fontSize: 18,fontWeight: FontWeight.w500,SizedBox(
            height: 15,Row(
            children: [
              OzetKutu(
                  icon_ozet: Icons.corporate_fare,color_ozet: Colors.lightBlue,title_ozet: "Üretilen",subtitle_ozet: context.watch<SantralViewModel>().uretimOzet.gunlukUretim + " m3"),OzetKutu(
                  icon_ozet: Icons.assignment_rounded,color_ozet: Colors.brown,title_ozet: "Bekleyen Üretim",subtitle_ozet: context.watch<SantralViewModel>().uretimOzet.bekleyenUretim + " m3"),);
  }

  Future<void> _cikisYap(BuildContext context) async {
    final _santralModel = Provider.of<SantralViewModel>(context,listen: false);
    await _santralModel.santralSignOut();
    final _userModel = Provider.of<UserViewModel>(context,listen: false);
    await _userModel.signOut();
  }
}

视图模型代码：

import 'package:cobasys_mobile/locator.dart';
import 'package:cobasys_mobile/models/signalr_santral_model.dart';
import 'package:cobasys_mobile/services/signalr_santral_service.dart';
import 'package:flutter/material.dart';

class SantralViewModel with ChangeNotifier {
  SignalRSantralService _signalRSantralService = locator<SignalRSantralService>();

  UretimOzet _uretimOzet;

  set uretimOzet(UretimOzet value) {
    _uretimOzet = value;
    notifyListeners();
  }

  UretimOzet get uretimOzet {
    if (_uretimOzet == null) {
      return UretimOzet(
          gunlukUretim: "",bekleyenUretim: "",uretilenSiparis: "",bekleyenSiparis: "",santralVerim: "");
    } else {
      return _uretimOzet;
    }
  }

  SantralViewModel() {
    _signalRSantralService.signalRSantralConnection();
    buildSantral();
  }

  Future<void> buildSantral() async {
    debugPrint("SignalRSantralService Başlatılıyor...");
    _signalRSantralService.connection.on("UretimOzet",(data) {
      if (data != null) {
        uretimOzet = UretimOzet.fromJson(data[0]);
        debugPrint(uretimOzet.gunlukUretim);
      }
    });
  }

  Future<bool> santralSignOut() {
    uretimOzet = null;
    _signalRSantralService.connection.stop();
    debugPrint("Santral connection kapatıldı.");
    return Future.value(true);
  }
}

我的小部件代码：

import 'package:flutter/material.dart';

class OzetKutu extends StatelessWidget {
  final IconData icon_ozet;
  final Color color_ozet;
  final String title_ozet;
  final String subtitle_ozet;

  const OzetKutu({Key key,this.icon_ozet,this.color_ozet,this.title_ozet,this.subtitle_ozet})
      : super(key: key);

  @override
  Widget build(BuildContext context) {
    debugPrint("Ozet Kutu reBuild");

    return Container(
      width: MediaQuery.of(context).size.width / 2,child: Card(
        child: Row(
          crossAxisAlignment: CrossAxisAlignment.start,children: [
            Padding(
              padding: const EdgeInsets.all(10.0),child: Container(
                child: Icon(
                  icon_ozet,size: 50,color: color_ozet,Expanded(
              child: Container(
                height: 70,child: Column(
                  mainAxisAlignment: MainAxisAlignment.center,children: [
                    Text(
                      title_ozet,style: TextStyle(fontSize: 14,fontWeight: FontWeight.w400),Text(
                      subtitle_ozet,style: TextStyle(fontSize: 18,fontWeight: FontWeight.w600),);
  }
}

型号代码：

// To parse this JSON data,do
//
//     final uretimOzet = uretimOzetFromJson(jsonString);

import 'dart:convert';

UretimOzet uretimOzetFromJson(String str) => UretimOzet.fromJson(json.decode(str));

String uretimOzetToJson(UretimOzet data) => json.encode(data.toJson());

class UretimOzet {
  UretimOzet({
    this.gunlukUretim,this.bekleyenUretim,this.uretilenSiparis,this.bekleyenSiparis,this.santralVerim,this.enerjiTuketim,});

  String gunlukUretim;
  String bekleyenUretim;
  String uretilenSiparis;
  String bekleyenSiparis;
  String santralVerim;
  String enerjiTuketim;

  factory UretimOzet.fromJson(Map<String,dynamic> json) => UretimOzet(
        gunlukUretim: json["gunlukUretim"] == null ? null : json["gunlukUretim"].toString(),bekleyenUretim: json["bekleyenUretim"] == null ? null : json["bekleyenUretim"].toString(),uretilenSiparis:
            json["uretilenSiparis"] == null ? null : json["uretilenSiparis"].toString(),bekleyenSiparis:
            json["bekleyenSiparis"] == null ? null : json["bekleyenSiparis"].toString(),santralVerim: json["santralVerim"] == null ? null : json["santralVerim"].toString(),enerjiTuketim: json["enerjiTuketim"] == null ? null : json["enerjiTuketim"].toString(),);

  Map<String,dynamic> toJson() => {
        "gunlukUretim": gunlukUretim == null ? null : gunlukUretim,"bekleyenUretim": bekleyenUretim == null ? null : bekleyenUretim,"uretilenSiparis": uretilenSiparis == null ? null : uretilenSiparis,"bekleyenSiparis": bekleyenSiparis == null ? null : bekleyenSiparis,"santralVerim": santralVerim == null ? null : santralVerim,"enerjiTuketim": enerjiTuketim == null ? null : enerjiTuketim,};
}