java - 在后台更新位置并检查 LocationSettings

Question

我想每隔几分钟在后台更新一次用户的位置。
我使用了这个示例代码 googlesamples/android-play-location
但将其更改为与 Service

一起使用

public class MyService extends Service implements
        GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener,
        LocationListener, ResultCallback<LocationSettingsResult>

但我无法检查位置设置

    protected void checkLocationSettings() {
        PendingResult<LocationSettingsResult> result =
                LocationServices.SettingsApi.checkLocationSettings(
                        mGoogleApiClient,
                        mLocationSettingsRequest
                );
        result.setResultCallback(this);
    }

    @Override
    public void onResult(LocationSettingsResult locationSettingsResult) {
        final Status status = locationSettingsResult.getStatus();
        switch (status.getStatusCode()) {
            case LocationSettingsStatusCodes.SUCCESS:
                Log.i(TAG, "All location settings are satisfied.");
                startLocationUpdates();
                break;
            case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                Log.i(TAG, "Location settings are not satisfied. Show the user a dialog to" +
                        "upgrade location settings ");

                try {
                    // Show the dialog by calling startResolutionForResult(), and check the result
                    // in onActivityResult().
                    status.startResolutionForResult(MainActivity.this, REQUEST_CHECK_SETTINGS);
                } catch (IntentSender.SendIntentException e) {
                    Log.i(TAG, "PendingIntent unable to execute request.");
                }
                break;
            case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
                Log.i(TAG, "Location settings are inadequate, and cannot be fixed here. Dialog " +
                        "not created.");
                break;
        }
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        switch (requestCode) {
            // Check for the integer request code originally supplied to startResolutionForResult().
            case REQUEST_CHECK_SETTINGS:
                switch (resultCode) {
                    case Activity.RESULT_OK:
                        Log.i(TAG, "User agreed to make required location settings changes.");
                        startLocationUpdates();
                        break;
                    case Activity.RESULT_CANCELED:
                        Log.i(TAG, "User chose not to make required location settings changes.");
                        break;
                }
                break;
        }
    }

因为这个方法需要一个Activity

status.startResolutionForResult(MainActivity.this, REQUEST_CHECK_SETTINGS);

如果我将之前的代码放在 MainActvity 中，我将不会有对 mGoogleApiClient 和 mLocationSettingsRequest 的引用

LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, mLocationSettingsRequest);

即使 Activity 被破坏，我也想升级并在后台保存位置。
使用服务是正确的做法吗？
如何检查位置设置？

[编辑]
我尝试使用 PendingIntent 和 IntentService

LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
                    mLocationRequest, mPendingIntent);

This method is suited for the background use cases, more specifically for receiving location updates, even when the app has been killed by the system.

与带有 Service 和 LocationListner 的版本相比有什么区别？

Answer 1

我找到了解决问题的方法。
为了访问主 Activity ，我使用了方法

MainActivity.getInstance()

主 Activity

public class MainActivity extends AppCompatActivity {
    private static MainActivity instance;

    public static MainActivity getInstance() {
        Log.i("MainActivity", "getInstance");
        return instance;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.i(TAG, "onCreate");
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // Instance of the MainActivity
        instance = this;
    }
    ...
   
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    Log.i(TAG, "onActivityResult");
    switch (requestCode) {
        // Check for the integer request code originally supplied to startResolutionForResult().
        case REQUEST_CHECK_SETTINGS:
            switch (resultCode) {
                case Activity.RESULT_OK:
                    Log.i(TAG, "User agreed to make required location settings changes.");
                    startService(intent);
                    break;
                case Activity.RESULT_CANCELED:
                    Log.i(TAG, "User chose not to make required location settings changes.");
                    break;
            }
            break;
        }
    }
}

服务

@Override
public void onResult(LocationSettingsResult locationSettingsResult) {
    final Status status = locationSettingsResult.getStatus();
    switch (status.getStatusCode()) {
        case LocationSettingsStatusCodes.SUCCESS:
            // All location settings are satisfied. The client can
            // initialize location requests here.
            Log.i(TAG, "All location settings are satisfied.");
            startLocationUpdates();
            break;
        case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
            // Location settings are not satisfied, but this can be fixed
            // by showing the user a dialog.
            Log.i(TAG, "Location settings are not satisfied. Show the user a dialog to " +
                    "upgrade location settings ");
            try {
                // Show the dialog by calling startResolutionForResult(),
                // and check the result in onActivityResult().
                status.startResolutionForResult(MainActivity.getInstance(), REQUEST_CHECK_SETTINGS);
            } catch (IntentSender.SendIntentException e) {
                // Ignore the error.
                Log.i(TAG, "PendingIntent unable to execute request.");
            }
            break;
        // The status will never be SETTINGS_CHANGE_UNAVAILABLE if use builder.setAlwaysShow(true);
        case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
            // Location settings are not satisfied. However, we have no way
            // to fix the settings so we won't show the dialog.
            Log.i(TAG, "Location settings are inadequate, and cannot be fixed here. Dialog " +
                    "not created.");
            break;
    }
}