Flutter - SwitchListTile - DRY代码

Question

完成新手，所以请耐心等待。关于如何使用DRY原则重构代码的问题。我确定可以在这样一个简单的例子上完成，所以这里就是....我的代码如下所示，显示了三个＆＃39; switchListTiles＆＃39;。我已经设法解决了如何在彼此之上创建3个switchListTiles，以及如何让它们单独打开/关闭。只是这意味着我将创建以下功能3次：

bool _value3 = false;

void _onChanged3(bool value3) {
    setState(() {
      _value3 = value3;
    });
  }

我确定有一种方法可以改变这一点，所以我不会有三次相同的代码。 任何帮助将不胜感激 非常感谢提前

    import 'package:flutter/material.dart';

    void main() {
      runApp(new MaterialApp(
        title: "Switch Widget Demo",
        home: new MyApp(),
      ));
    }

    class MyApp extends StatefulWidget {
      @override
      _MyAppState createState() => _MyAppState();
    }

    class _MyAppState extends State<MyApp> {

      bool _value = false;

      void _onChanged(bool value) {
        setState(() {
          _value = value;
        });
      }

      bool _value2 = false;

      void _onChanged2(bool value2) {
        setState(() {
          _value2 = value2;
        });
      }

      bool _value3 = false;

      void _onChanged3(bool value3) {
        setState(() {
          _value3 = value3;
        });
      }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Switch Demo"),
        backgroundColor: Colors.redAccent,
        centerTitle: true,
      ),
      body: Container(
        padding: EdgeInsets.all(32.0),
        child: Column(
          children: <Widget>[

            Switch(value: _value,
              onChanged: (bool value) {_onChanged(value);}),
            SwitchListTile(value: _value,
              title: Text("Click Me"),
              activeColor: Colors.red,
              secondary: Icon(Icons.home),
              subtitle: Text("For my small print"),
              onChanged: (bool value) {_onChanged(value);}),

            SwitchListTile(value: _value2,
                title: Text("Click Me Again Please"),
                activeColor: Colors.lightGreen,
                secondary: Icon(Icons.perm_identity),
                onChanged: (bool value2) {_onChanged2(value2);}),

            SwitchListTile(value: _value3,
                title: Text("And Again Please"),
                activeColor: Colors.blueGrey,
                subtitle: Text("Some more small print"),
                secondary: Icon(Icons.person),
                onChanged: (bool value) {_onChanged3(value);}),


          ],
        ),
      ),
    );
  }
}

Answer 1

您只需将 public class MyService extends Service { final static String TAG = MyService.class.getName(); ReceiverCall receiverCall; private static final int NOTIFICATION_ID = 1; MyService (){ super(); } class Mythread implements Runnable { int service_id; Mythread(int service_id) { this.service_id = service_id; } @Override public void run() { int i = 0; synchronized (this) { // while (i < 10) { try { wait(2500); i++; processStartNotification(String.valueOf(i)); } catch (InterruptedException e) { e.printStackTrace(); } // } } } } @Override public void onCreate() { receiverCall= new ReceiverCall(); super.onCreate(); } @Override public void onDestroy() { super.onDestroy(); super.onDestroy(); Toast.makeText(getApplicationContext(), "Service Task destroyed", Toast.LENGTH_LONG).show(); Intent myIntent = new Intent(getApplicationContext(), MyService.class); startService(myIntent); } @Override public void onTaskRemoved(Intent rootIntent) { super.onTaskRemoved(rootIntent); Intent myIntent = new Intent(getApplicationContext(), MyService.class); startService(myIntent); } @Override public int onStartCommand(Intent intent, int flags, int startId) { Thread thread = new Thread(new Mythread(startId)); thread.start(); return START_STICKY; } @Nullable @Override public IBinder onBind(Intent intent) { return null; } private void processStartNotification(String s) { // Do something. For example, fetch fresh data from backend to create a rich notification? final NotificationCompat.Builder builder = new NotificationCompat.Builder(this); builder.setContentTitle("Scheduled Notification") .setAutoCancel(true) .setColor(getResources().getColor(R.color.colorAccent)) .setContentText(" Notification Service"+s) .setSmallIcon(R.drawable.ic_launcher_background); builder.setDeleteIntent(receiverCall.getDeleteIntent(this)); final NotificationManager manager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE); manager.notify(NOTIFICATION_ID, builder.build()); } } BroadcastReceiver Class : public class ReceiverCall extends BroadcastReceiver { private static final String ACTION_START_NOTIFICATION_SERVICE = "ACTION_START_NOTIFICATION_SERVICE"; private static final String ACTION_DELETE_NOTIFICATION = "ACTION_DELETE_NOTIFICATION"; private static final int NOTIFICATIONS_INTERVAL_IN_HOURS = 2; @Override public void onReceive(Context context, Intent intent) { Log.i("Service Stops", "Ohhhhhhh"); context.startService(new Intent(context, MyService.class)); } public static PendingIntent getDeleteIntent(Context context) { Intent intent = new Intent(context, ReceiverCall.class); intent.setAction(ACTION_DELETE_NOTIFICATION); return PendingIntent.getBroadcast(context, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT); } } 重构为其单独的类，然后在父窗口小部件中生成 <service android:name=".MyService" android:exported="true" android:stopWithTask="false"></service> <receiver android:name=".ReceiverCall"> <intent-filter> <action android:name="com.servicesex" /> <action android:name="android.intent.action.BOOT_COMPLETED" /> </intent-filter> </receiver> 。

在这里，我创建了20个代码较少的代码：

SwitchListTiles