Question

我正在开发一个应用程序，它可以使用预定义的时间（使用警报管理器）搜索某个Wi-Fi SSID并在找到时使电话静音。我希望我的应用程序能够在后台运行，因此我为Wi-Fi搜索提供了服务等级。另外，我创建了一个类，可以检测是否找到了特定的Wi-Fi（在范围内）。我将Wi-Fi检测类放在服务类中。

问题：

当应用程序在后台运行时（它成功搜索并检测到Wi-Fi），服务正常工作，但当我关闭应用程序时，服务正常工作（服务已启动），但Wi-Fi检测器类无法检测到任何Wi -Fi就好像没有Wi-Fi在范围内。我不知道为什么会出现这个问题，我希望有人不能帮助我。

这是我服务的代码：

import android.annotation.SuppressLint;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.media.AudioManager;
import android.net.wifi.ScanResult;
import android.net.wifi.WifiManager;
import android.os.IBinder;
import android.support.annotation.Nullable;
import android.widget.Toast;

import java.util.List;

/**
 * Created by Msi on 1/6/2018.
 */

public class MyService extends Service{
    AudioManager audio;
    String wifis[];
    WifiManager mainWifiObj;
    WifiScanReceiver wifiReciever;
    String accesspoint = "Silent_Area";
    public boolean founded = false;
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {//this is invoked first
        super.onCreate();
        Toast.makeText(this,"serivce is created",Toast.LENGTH_LONG).show();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {//work is done here
        mainWifiObj = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
        wifiReciever = new WifiScanReceiver();
        audio = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
        Toast.makeText(this,"serivce is started",Toast.LENGTH_LONG).show();
        if(!mainWifiObj.isWifiEnabled()){
            mainWifiObj.setWifiEnabled(true);
        }
        System.out.println("-=--=-=RECIEVED Silencer-=--=-=");
        final int[] duration = {0};
        Thread thread = new Thread(new Runnable() {
            @Override
            public void run() {
                while (duration[0] < 15 * 60 * 1000) {
                    while (duration[0] < 7 * 60 * 1000){
                        System.out.println("thread Searches every 5 sec");
                        mainWifiObj.startScan();
                        if (founded == true) {
                            System.out.println("found");
                            audio.setRingerMode(1);
                        }
                        if (founded == false) {
                            System.out.println("didnt find");
                            audio.setRingerMode(AudioManager.RINGER_MODE_NORMAL);
                        }
                        System.out.println("hello keep searching ");
                        try {
                            Thread.sleep(1000 * 5);
                        } catch (InterruptedException e) {
                            e.printStackTrace();
                        }
                        duration[0] += 5 * 1000;
                    }
                    System.out.println("thread searches every 30 sec");
                    mainWifiObj.startScan();
                    if (founded == true) {
                        System.out.println("found");
                        audio.setRingerMode(1);
                    }
                    if (founded == false) {
                        System.out.println("didnt find");
                        audio.setRingerMode(AudioManager.RINGER_MODE_NORMAL);
                    }
                    System.out.println("hello keep searching ");
                    try {
                        Thread.sleep(1000 * 30);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    duration[0] += 30 * 1000;
                }
                System.out.println("15 min has passed");
                stopSelf();
            }
        });

        thread.start();
        return super.onStartCommand(intent, flags, startId);

    }

    @Override
    public void onDestroy() {//to destroy
        Toast.makeText(this,"serivce is stopped",Toast.LENGTH_LONG).show();
        super.onDestroy();
        stopSelf();
    }


    public class WifiScanReceiver extends BroadcastReceiver {

        @SuppressLint("UseValueOf")
        public void onReceive(Context c, Intent intent) {
            List<ScanResult> wifiScanList = mainWifiObj.getScanResults();
            wifis = new String[wifiScanList.size()];
            for (int i = 0; i < wifiScanList.size(); i++) {
                wifis[i] = ((wifiScanList.get(i)).toString());
            }
            String filtered[] = new String[wifiScanList.size()];
            int counter = 0;
            final AudioManager manual = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
            for (String eachWifi : wifis) {
                String[] temp = eachWifi.split(",");
                filtered[counter] = temp[0].substring(5).trim();
                counter++;
                System.out.println(/*temp[0].substring(5).trim()*/temp[0]+temp[1]+temp[2]+temp[3]+temp[4]+temp[5]);

                if (accesspoint.equals(temp[0].substring(5).trim())) {
                    System.out.println("== Founded ==");
                    founded = true;
                    break;
                }
                else{
                    founded=false;
                }
            }
        }
    }

}

Answer 1

尝试扩展IntentService而不是Service或创建ServiceHandler

两者的例子都在API指南中：

https://developer.android.com/guide/components/services.html

无法检测到Wi-Fi的服务

1 个答案: