android - 由服务扩展的类 Activity 问题

Question

我有这段代码，如果一段时间之前分数不同，我会在其中发出通知。但是不要使用这段代码，因为 Android Studio 告诉我:

1) 无法解析构造函数 Intent(anonymous.retrofit2.Callback, java.lang.Class)

2)

getActivity() 或变量 this 在带有参数的代码中不起作用:Cannot resolve method getActivity()

`

package com.example.luky.nhlvysledky;

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Handler;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.NotificationCompat;
import android.support.v4.app.NotificationManagerCompat;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

import com.example.luky.nhlvysledky.api_data.ApiTools;
import com.example.luky.nhlvysledky.api_data.LastMatchModel;
import com.google.gson.JsonArray;
import com.google.gson.JsonObject;

import java.util.ArrayList;
import java.util.List;

import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;

public class GameChangeService extends Service {
    private final static String TAG = "GameChangeService";
    private BroadcastReceiver broadcastReceiver;
    private Handler h;
    private SharedPreferences sp;
    Notification notif;
    NotificationManager notifManager;
    private SharedPreferences.Editor ed;
    private Runnable r;
    private int id;

    private String CHANNEL_ID = "ID";
    private int notifId = 1000;


    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        sp = getSharedPreferences(Tools.PACKAGE_NAME, Context.MODE_PRIVATE);
        ed = sp.edit();
        notifManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        h = new Handler();
        broadcastReceiver = new BroadcastReceiver() {
            @Override
            public void onReceive(Context context, Intent intent) {
                stopSelf();
            }
        };
        LocalBroadcastManager.getInstance(this).registerReceiver(broadcastReceiver, new IntentFilter(Tools.INTENT_ACTION_STOP_SERVICE));
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        id = intent.getIntExtra(Tools.INTENT_EXTRA_ID, -1);
        if (id == -1) {
            stopSelf();
        } else {
            r = new Runnable() {
                @Override
                public void run() {
                    doStuff(id);
                    h.postDelayed(r, 15000);
                }
            };
            h.post(r);

            return Service.START_STICKY;
        }
        //TOTO TU JE VELMI DISKUTABILNE
        return Service.START_STICKY;
    }

    private void doStuff(final int id) {
        //TODO: Checkni pls ci je boxscore updatovany live alebo nie. Ak je tak ho mozes pouzit v IApiDefinition namiesto live feed
        //TODO: JA> V schedule je s gamepk aj online zapas s golmi - staci to pouzit
        ApiTools.getApi().getGame(id).enqueue(new Callback<JsonObject>() {
            @Override
            public void onResponse(Call<JsonObject> call, Response<JsonObject> response) {
                if (sp.contains(Integer.toString(id))) {
                    int povodnyPocetGolovVZapase = sp.getInt(Integer.toString(id), 0);

                    //Z responsu zistit kolko eventov je teraz v zapase, t.j. ci uz zapas zacal.
                    //Dalej zistit ci su tam nejake eventy, ktore maju typ goal alebo ENDGAME (asi).
                    //AK sa zmenil pocet golov, tak posli notifikaciu ze padol gol aj s novym stavom

                    JsonObject data = response.body();
                    //pouzijem lastmatchmodel, aj ked to nie je pre toto robene, ale data mi stacia aj z neho
                    //List<LastMatchModel> livezapasy = new ArrayList<>();
                    //vytiahnem si zoznam
                    JsonArray zoznamZapasovZJsonu = data.get("dates").getAsJsonArray();
                    for (int i = 0; i < zoznamZapasovZJsonu.size(); i++) {
                        //pouzijem lastmatchmodel, aj ked to nie je pre toto robene, ale data mi stacia aj z neho
                        LastMatchModel novyZapas = new LastMatchModel();
                        JsonObject zapasDate = zoznamZapasovZJsonu.get(i).getAsJsonObject();

                        JsonArray games = zapasDate.get("games").getAsJsonArray();
                        if (games.size() == 1) {
                            JsonObject teams = games.get(0).getAsJsonObject().get("teams").getAsJsonObject();

                            int golyHostia = teams.get("away").getAsJsonObject().get("score").getAsInt();
                            String timHostia = teams.get("away").getAsJsonObject().get("team").getAsJsonObject().get("name").getAsString();

                            int golyDomaci = teams.get("home").getAsJsonObject().get("score").getAsInt();
                            String timDomaci = teams.get("home").getAsJsonObject().get("team").getAsJsonObject().get("name").getAsString();

                            if (golyDomaci + golyHostia != povodnyPocetGolovVZapase) {

/*HERE IS THIS CODE TO REPAIR*/
                                Intent intent = new Intent(this, MatchNotification.class);
                                PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);
                                createNotificationChannel();


                                final NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(getActivity(), CHANNEL_ID)
                                        .setSmallIcon(R.mipmap.ic_launcher)
                                        .setContentTitle("GOAL")
                                        .setContentText(timDomaci + golyDomaci + " vs " + golyHostia + timHostia)
                                        .setContentIntent(pendingIntent)
                                        .setPriority(NotificationCompat.PRIORITY_DEFAULT);

                                NotificationManagerCompat nm = NotificationManagerCompat.from(getActivity());
                                nm.notify(notifId, mBuilder.build());

                            }
                        }
                    }
/*HERE IS ENDING CODE*/

                } else {
                    int povodnyPocetEventovVZapase = 0;
                }
            }

            @Override
            public void onFailure(Call<JsonObject> call, Throwable t) {
                Log.e(GameChangeService.TAG, "Nebavi to ");
            }
        });
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        if (h != null)
            h.removeCallbacks(r);
        LocalBroadcastManager.getInstance(this).unregisterReceiver(broadcastReceiver);
    }

    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            CharSequence name = "Name of the channel";
            String description = "Description of the channel";
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
            channel.setDescription(description);
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }
}
`

你能帮我解决这个问题吗？在 fragments 中可以使用 getActivity 或 getContext，但是这个类不是通过 Fragment 扩展的，而是通过 Service 扩展的。谢谢!

Answer 1

在 Intent intent = new Intent(this, MatchNotification.class);行你在匿名的方法new Callback<JsonObject>()对象。

意思是this是 Callback<JsonObject>此时。

要修复它，您必须指定要使用的“this”。作为Intent需要 Context ，你要找的就是你的Service对象(因为Service在Android中是Context)

Intent intent = new Intent(GameChangeService.this, MatchNotification.class);例如。