Question

修改：我已将代码添加到最近尝试的底部。

我正在尝试按照示例代码here。我在检索最后一个已知位置时遇到困难。我尝试了几种方法。

在上面的链接示例中，他们使用“GPSTracker”。它给出了错误“无法解析符号'GPSTracker'”。是否有我缺少的导入？
我尝试使用LocationManager获取位置，如this example所示，但我收到错误“无法解析方法'requestLocationUpdates（java.lang.String，long，long，anonymous java.util.TimerTask）'” 。我也尝试将第三个参数更改为浮点数并得到类似的错误。
我尝试使用FusedLocationProviderApi获取位置。我将新的GoogleApiClient.Builder添加到我的onCreate（）方法，导入了com.google.android.gms.location.FusedLocationProviderApi，并更新了build.gradle文件。但是当我将“this”添加到.addConnectionCallbacks（this）和.addOnConnectionFailedListener（this）时，它会在新的GoogleApiClient.Builder方法中出错。根据我的阅读，这是最佳选择，因为它针对最少的电池使用进行了优化？

我对如何获得位置感到茫然。我的目标与第一个链接的示例类似。我想构建一个在后台运行的服务，并将在指定的时间间隔内将其位置的更新发送到服务器。到目前为止，我已经创建了两个按钮，允许服务启动和停止。服务启动后，它会检查设备是否有移动数据。然后，我想要检查位置是否已打开并且有GPS信号。我只想要GPS信号而不是网络位置。最后，如果数据和位置/ GPS信号都为真，那么它会在指定的时间间隔内将其位置发送到服务器。到目前为止，这是我的代码。

MainActivity.java

package com.testtracker;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;

public class MainActivity extends Activity
{
@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    MyService.setUp(this);
}

@Override
public boolean onCreateOptionsMenu(Menu menu)
{
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item)
{
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings)
    {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

public void startService(View view)
{
    startService(new Intent(getBaseContext(), MyService.class));
}

public void stopService(View view)
{
    stopService(new Intent(getBaseContext(), MyService.class));
}
}

MyService.java

package com.testtracker;

import android.app.Activity;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.os.IBinder;
import android.os.PowerManager;
import android.widget.Button;
import android.widget.Toast;

import java.lang.reflect.Method;
import java.util.Timer;
import java.util.TimerTask;

public class MyService extends Service
{
PowerManager powerManager;
PowerManager.WakeLock wakeLock;
static Button startButton;
static Button stopButton;

public static void setUp(Activity act)
{
    startButton = (Button)act.findViewById(R.id.button2);
    stopButton = (Button)act.findViewById(R.id.button);
}

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

@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
    powerManager = (PowerManager)getSystemService(Context.POWER_SERVICE);
    wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MyWakeLock");
    wakeLock.acquire();

    startButton.setEnabled(false);
    stopButton.setEnabled(true);

    final ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);

    Timer timer = new Timer();
    final int TIME_INTERVAL = 10000;

    Toast.makeText(this, "Service Started", Toast.LENGTH_SHORT).show();

    timer.schedule(new TimerTask()
    {
        boolean mobileDataEnabled = false;

        public void run() {
            try {
                //Check if phone has data
                Class cmClass = Class.forName(connectivityManager.getClass().getName());
                Method method = cmClass.getDeclaredMethod("getMobileDataEnabled");
                method.setAccessible(true);
                mobileDataEnabled = (Boolean) method.invoke(connectivityManager);

                if (mobileDataEnabled)
                {
                    //Has data. Check if phone has location and GPS signal. If it does, get location and send to server.
                }
                else
                {
                    //No data. Check again during the next timer interval.
                }

            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }, 0, TIME_INTERVAL);

    return START_STICKY;
}

@Override
public void onDestroy()
{
    super.onDestroy();
    wakeLock.release();
    startButton.setEnabled(true);
    stopButton.setEnabled(false);
    Toast.makeText(this, "Service Stopped", Toast.LENGTH_SHORT).show();
}
}

编辑：

通过我一直在进行的尝试（记录在我的下面的评论中），我想我会发布更新后的代码。我将使用当前的尝试更新以下代码，并将上述代码保留为原始代码。我最好使用FusedLocationProviderApi或Little Fluffy Location Library，因为它们似乎已针对在后台运行进行了优化。

MainActivity.java

package com.testtracker;

import android.app.Activity;
import android.content.Intent;
import android.location.LocationManager;
import android.os.Bundle;
import android.provider.Settings;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity implements Button.OnClickListener
{
Button startButton;
Button stopButton;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    startButton = (Button)findViewById(R.id.button2);
    stopButton = (Button)findViewById(R.id.button);

    startButton.setEnabled(true);
    stopButton.setEnabled(false);

    LocationManager service = (LocationManager)getSystemService(LOCATION_SERVICE);
    boolean locationEnabled = service.isProviderEnabled(LocationManager.GPS_PROVIDER);

    if(!locationEnabled)
    {
        Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
        startActivity(intent);
    }

    startButton.setOnClickListener(this);
    stopButton.setOnClickListener(this);
}

@Override
public boolean onCreateOptionsMenu(Menu menu)
{
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item)
{
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings)
    {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@Override
public void onClick(View v)
{
    switch(v.getId())
    {
        case R.id.button2:
            startButton.setEnabled(false);
            stopButton.setEnabled(true);

            Intent intentStart = new Intent(this, MyService.class);
            startService(intentStart);
            break;

        case R.id.button:
            startButton.setEnabled(true);
            stopButton.setEnabled(false);

            Intent intentStop = new Intent(this, MyService.class);
            stopService(intentStop);
            break;
    }

}
}

MyService.java

package com.testtracker;

import android.app.Activity;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.net.ConnectivityManager;
import android.os.Bundle;
import android.os.IBinder;
import android.os.Looper;
import android.os.PowerManager;
import android.widget.Toast;

import java.lang.reflect.Method;
import java.util.Timer;
import java.util.TimerTask;

public class MyService extends Service implements LocationListener
{
protected LocationManager locationManager;
protected LocationListener locationListener;

PowerManager powerManager;
PowerManager.WakeLock wakeLock;

public void onCreate()
{
    Toast.makeText(this, "in on create", Toast.LENGTH_SHORT).show();
}

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

@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
    powerManager = (PowerManager)getSystemService(Context.POWER_SERVICE);
    wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MyWakeLock");
    wakeLock.acquire();

    final ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);

    Timer timer = new Timer();
    final int TIME_INTERVAL = 10000;

    Looper.prepare(); //Fatal error said this must be added?

    Toast.makeText(this, "Service Started", Toast.LENGTH_SHORT).show();

    timer.schedule(new TimerTask()
    {
        boolean mobileDataEnabled = false;

        public void run() {
            try {
                //Check if phone has data
                Class cmClass = Class.forName(connectivityManager.getClass().getName());
                Method method = cmClass.getDeclaredMethod("getMobileDataEnabled");
                method.setAccessible(true);
                mobileDataEnabled = (Boolean) method.invoke(connectivityManager);

                if (mobileDataEnabled)
                {
                    //Has data. Check if phone has location and GPS signal. If it does, get location and send to server.
                    locationManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
                    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

                    final Criteria cri = new Criteria();

                    String bestProvider = locationManager.getBestProvider(cri, true);

                    Location loc = locationManager.getLastKnownLocation(bestProvider);
                    double lat = loc.getLatitude();
                    double lng = loc.getLongitude();

                    Toast.makeText(getBaseContext(), lat + " - " + lng, Toast.LENGTH_SHORT).show();
                }

            } catch (Exception e) {
                e.printStackTrace();
                onDestroy();
            }
        }
    }, 0, TIME_INTERVAL);

    return START_STICKY;
}

@Override
public void onDestroy()
{
    super.onDestroy();
    wakeLock.release();

    Toast.makeText(this, "Service Stopped", Toast.LENGTH_SHORT).show();
}

@Override
public void onLocationChanged(Location location) {

}

@Override
public void onStatusChanged(String provider, int status, Bundle extras) {

}

@Override
public void onProviderEnabled(String provider) {

}

@Override
public void onProviderDisabled(String provider) {

}
}

logcat的错误看起来像是由Looper.prepare（）引起的。如果我不添加，那么我得到致命错误“无法在未调用Looper.prepare（）的线程内创建处理程序”。不能赢这个吗？

2263-2263/com.testtracker E/AndroidRuntime﹕ FATAL EXCEPTION: main
Process: com.testtracker, PID: 2263
java.lang.RuntimeException: Unable to start service com.testtracker.MyService@18edb4e4 with Intent { cmp=com.testtracker/.MyService }: java.lang.RuntimeException: Only one Looper may be created per thread
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2914)
at android.app.ActivityThread.access$2100(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1401)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)
Caused by: java.lang.RuntimeException: Only one Looper may be created per thread
at android.os.Looper.prepare(Looper.java:76)
at android.os.Looper.prepare(Looper.java:71)
at com.testtracker.MyService.onStartCommand(MyService.java:53)
at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:2897)
at android.app.ActivityThread.access$2100(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1401)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:903)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:698)

获取服务中的位置

编辑：

0 个答案: