Android-AlertDialog（）がクラッシュする

Question

私のプロジェクトを実行しているときにこのエラーが発生しています。私は検索して、問題はコンテキストと関係があると思いますが、解決方法はわかりません。

マイコード：ここで（私はそれが法showSettingsAlert（上にあるエラーを考える））

public class GPSTracker extends Service implements LocationListener { 

private final Context mContext; 

private TextView textView; 


// flag for GPS status 
boolean isGPSEnabled = false; 

// flag for network status 
boolean isNetworkEnabled = false; 

// flag for GPS status 
boolean canGetLocation = false; 

Location location; // location 
double latitude; // latitude 
double longitude; // longitude 

// The minimum distance to change Updates in meters 
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 1000; // 1000 meters 

// The minimum time between updates in milliseconds 
private static final long MIN_TIME_BW_UPDATES = 60000 * 60 * 1; // 60 minute 

// Declaring a Location Manager 
protected LocationManager locationManager; 

public GPSTracker(Context context) { 
    this.mContext = context; 
    getLocation(); 
} 

public Location getLocation() { 
    try { 
     locationManager = (LocationManager) mContext.getSystemService(LOCATION_SERVICE); 

     // getting GPS status 
     isGPSEnabled = locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER); 

     // getting network status 
     isNetworkEnabled = locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER); 

     if (!isGPSEnabled && !isNetworkEnabled) { 
      // no network provider is enabled 
     } else { 
      this.canGetLocation = true; 
      // First get location from Network Provider 
      if (isNetworkEnabled) { 
       locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
       Log.d("Network", "Network"); 
       if (locationManager != null) { 
        location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); 
        if (location != null) { 
         latitude = location.getLatitude(); 
         longitude = location.getLongitude(); 
        } 
       } 
      } 
      // if GPS Enabled get lat/long using GPS Services 
      if (isGPSEnabled) { 
       if (location == null) { 
        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this); 
        Log.d("GPS Enabled", "GPS Enabled"); 
        if (locationManager != null) { 
         location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER); 
         if (location != null) { 
          latitude = location.getLatitude(); 
          longitude = location.getLongitude(); 
         } 
        } 
       } 
      } 
     } 

    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
    stopUsingGPS(); 
    return location; 

} 

/** 
* Stop using GPS listener 
* Calling this function will stop using GPS in your app 
* */ 
public void stopUsingGPS(){ 
    if(locationManager != null){ 
     locationManager.removeUpdates(GPSTracker.this); 
    } 
} 

/** 
* Function to get latitude 
* */ 
public double getLatitude(){ 
    if(location != null){ 
     latitude = location.getLatitude(); 
    } 

    // return latitude 
    return latitude; 
} 

/** 
* Function to get longitude 
* */ 
public double getLongitude(){ 
    if(location != null){ 
     longitude = location.getLongitude(); 
    } 

    // return longitude 
    return longitude; 
} 

/** 
* Function to check GPS/wifi enabled 
* @return boolean 
* */ 
public boolean canGetLocation() { 
    return this.canGetLocation; 
} 

/** 
* Function to show settings alert dialog 
* On pressing Settings button will lauch Settings Options 
* */ 
public void showSettingsAlert(){ 
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext); 


    // Setting Dialog Title 
    alertDialog.setTitle("GPS is settings"); 

    // Setting Dialog Message 
    alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?"); 

    // On pressing Settings button 
    alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog,int which) { 
      Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
      mContext.startActivity(intent); 
     } 
    }); 

    // on pressing cancel button 
    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() { 
     public void onClick(DialogInterface dialog, int which) { 
      dialog.cancel(); 
     } 
    }); 

    // Showing Alert Message 
    alertDialog.show(); 
} 

@Override 
public void onLocationChanged(Location location) { 
    textView.append("\n "+location.getLatitude()+" "+location.getLongitude()); 
} 

@Override 
public void onProviderDisabled(String provider) { 
    Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS); 
    mContext.startActivity(intent); 
} 

@Override 
public void onProviderEnabled(String provider) { 
} 

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

@Override 
public IBinder onBind(Intent arg0) { 
    return null; 
} 

} 

は私のLogcatです：

10-25 20:29:30.277 10524-10524/com.example.nunog.myapplication12 E/AndroidRuntime: FATAL EXCEPTION: main 
                       Process: com.example.nunog.myapplication12, PID: 10524 
                       java.lang.RuntimeException: Unable to start service com.example.nunog.myapplication12.Anomaly@424d1620 with Intent { cmp=com.example.nunog.myapplication12/.Anomaly (has extras) }: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application 
                        at android.app.ActivityThread.handleServiceArgs(ActivityThread.java:3006) 
                        at android.app.ActivityThread.access$2200(ActivityThread.java:174) 
                        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1404) 
                        at android.os.Handler.dispatchMessage(Handler.java:102) 
                        at android.os.Looper.loop(Looper.java:146) 
                        at android.app.ActivityThread.main(ActivityThread.java:5593) 
                        at java.lang.reflect.Method.invokeNative(Native Method) 
                        at java.lang.reflect.Method.invoke(Method.java:515) 
                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283) 
                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099) 
                        at dalvik.system.NativeStart.main(Native Method) 
                       Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application 
                        at android.view.ViewRootImpl.setView(ViewRootImpl.java:775) 
                        at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:278) 
                        at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69) 
                        at android.app.Dialog.show(Dialog.java:301) 
                        at android.app.AlertDialog$Builder.show(AlertDialog.java:957) 
                        at com.example.nunog.myapplication12.GPSTracker.showSettingsAlert(GPSTracker.java:176) 

Answer 1

はあなたのコンテキストを使用していることを確認しアクティビティアプリケーションクラスです。活動とアプリケーションコンテキストの間で必要に応じて詳細については は、Serviceがコンテキストであるため、代わりにmContextのコンテキストとしてthisを使用してみてください https://stackoverflow.com/a/35189629/1380032

Answer 2

をrefer-してください。 また、getLocation()メソッドをonCreate()またはonStartCommand()に呼び出す必要があります。 Serviceクラスには既にコンストラクタがあり、コンストラクタをオーバーライドしないでください。