android - 启用 GPS 的 LocationSettingsRequest 对话框 - 跳过了 onActivityResult()

Question

我的部分应用需要定位服务，所以如果定位当前处于关闭状态，应用会提示用户启用它。 Here我是这样做的:(也见于 this Stack Overflow 答案)

LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
            .addLocationRequest(mLocationRequest);
builder.setAlwaysShow(true);

PendingResult<LocationSettingsResult> result = LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, builder.build());

result.setResultCallback(new ResultCallback<LocationSettingsResult>() 
{
     @Override
     public void onResult(LocationSettingsResult result) 
     {
         final Status status = result.getStatus();
         final LocationSettingsStates = result.getLocationSettingsStates();
         switch (status.getStatusCode()) 
         {
             case LocationSettingsStatusCodes.SUCCESS:
                 // All location settings are satisfied. The client can initialize location
                 // requests here.
                 ...
                 Log.d("onResult", "SUCCESS");
                 break;
             case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                 // Location settings are not satisfied. But could be fixed by showing the user
                 // a dialog.
                 Log.d("onResult", "RESOLUTION_REQUIRED");
                 try 
                 {
                     // Show the dialog by calling startResolutionForResult(),
                     // and check the result in onActivityResult().
                     status.startResolutionForResult(OuterClass.this, REQUEST_LOCATION);
                 } 
                 catch (SendIntentException e) 
                 {
                     // Ignore the error.
                 }
                 break;
             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.d("onResult", "UNAVAILABLE");
                 break;
         }
     }
 });

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data)
{
    // This log is never called
    Log.d("onActivityResult()", Integer.toString(resultCode));

    final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);
    switch (requestCode)
    {
        case REQUEST_LOCATION:
            switch (resultCode)
            {
                case Activity.RESULT_OK:
                {
                    // All required changes were successfully made
                    break;
                }
                case Activity.RESULT_CANCELED:
                {
                    // The user was asked to change settings, but chose not to
                    break;
                }
                default:
                {      
                    break;
                }
            }
            break;
    }
}

这段代码运行良好，但是，onActivityResult() 总是被跳过。用户是否在 Dialog、onActivityResult() 中按下 Yes、No 或 back 不运行。

我需要Android调用onActivityResult()，所以如果用户选择不开启定位服务，我可以适当处理。

Google 的开发者页面(以及上面的代码)明确指出应该调用 onActivityResult()。有谁知道它为什么被跳过？

我也不知道这行的目的是什么:

final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);

谢谢!

编辑:关于我的应用程序结构的基本信息:

• 此代码包含在 Fragment 的 onResume() 方法中，该方法实现了 GoogleApiClient.ConnectionCallbacks、GoogleApiClient.OnConnectionFailedListener 和 LocationListener 接收位置更新。示例见 here .
• 在 onLocationChanged() 中，Fragment 将有一个自定义的 View 调用 invalidate() 并重新绘制更新信息。

Answer 1

更新

下面的原始答案是使用 Java 和现已弃用的 SettingsApi .

这是使用 Kotlin 和 SettingsClient 的更现代的方法:

fun showEnableLocationSetting() {
    activity?.let {
        val locationRequest = LocationRequest.create()
        locationRequest.priority = LocationRequest.PRIORITY_HIGH_ACCURACY

        val builder = LocationSettingsRequest.Builder()
                .addLocationRequest(locationRequest)

        val task = LocationServices.getSettingsClient(it)
                .checkLocationSettings(builder.build())

        task.addOnSuccessListener { response ->
            val states = response.locationSettingsStates
            if (states.isLocationPresent) {
                //Do something
            }
        }
        task.addOnFailureListener { e ->
            if (e is ResolvableApiException) {
                try {
                    // Handle result in onActivityResult()
                    e.startResolutionForResult(it,
                            MainActivity.LOCATION_SETTING_REQUEST)
                } catch (sendEx: IntentSender.SendIntentException) { }
            }
        }
    }
}

在MainActivity中，定义常量:

companion object {
    const val LOCATION_SETTING_REQUEST = 999
}

原始答案:

看起来主要问题是您将所有代码都放在一个 fragment 中，并且由于 startResolutionForResult() 需要将 Activity 传递给它，因此 Activity 是获取 onActivityResult 的原因() 回调。

解决这个问题的一种方法是使用所描述的技术here ，结果进来时，从Activity中手动调用Fragment的onActivityResult()方法。

我刚刚完成了这个简单的示例。

首先是Activity，它添加了Fragment，并且还具有将onActivityResult()的结果传递给Fragment的功能:

public class MainActivity extends AppCompatActivity{

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

        lFrag = LocationFragment.newInstance();
        getSupportFragmentManager().beginTransaction().add(R.id.fragment_container, lFrag).commit();

    }
    
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if (requestCode == LocationFragment.REQUEST_LOCATION){
            lFrag.onActivityResult(requestCode, resultCode, data);
        }
        else {
            super.onActivityResult(requestCode, resultCode, data);
        }
    }
}

这是 fragment ，它包含显示对话框和处理结果的所有功能。在这个简单的示例中，我只是使用 Toast 消息来验证它是否按预期工作。请注意，我在这里对您问题中的代码所做的主要更改是使用 getActivity() 来获取调用 startResolutionForResult() 所需的 Activity 引用>.

public class LocationFragment extends Fragment
        implements GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener {


    LocationRequest mLocationRequest;
    GoogleApiClient mGoogleApiClient;
    PendingResult<LocationSettingsResult> result;
    final static int REQUEST_LOCATION = 199;

    public static LocationFragment newInstance() {
        LocationFragment fragment = new LocationFragment();
        return fragment;
    }

    public LocationFragment() {
        // Required empty public constructor
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {

        mGoogleApiClient = new GoogleApiClient.Builder(getActivity())
                .addApi(LocationServices.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this).build();
        mGoogleApiClient.connect();

        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_location, container, false);
    }


    @Override
    public void onResume() {
        super.onResume();
    }

    @Override
    public void onConnected(Bundle bundle) {

        mLocationRequest = LocationRequest.create();
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mLocationRequest.setInterval(30 * 1000);
        mLocationRequest.setFastestInterval(5 * 1000);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(mLocationRequest);
        builder.setAlwaysShow(true);

        result = LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, builder.build());

        result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            @Override
            public void onResult(LocationSettingsResult result) {
                final Status status = result.getStatus();
                //final LocationSettingsStates state = result.getLocationSettingsStates();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:
                        // All location settings are satisfied. The client can initialize location
                        // requests here.
                        //...
                        break;
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied. But could be fixed by showing the user
                        // a dialog.
                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            status.startResolutionForResult(
                                    getActivity(),
                                    REQUEST_LOCATION);
                        } catch (IntentSender.SendIntentException e) {
                            // Ignore the error.
                        }
                        break;
                    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.
                        //...
                        break;
                }
            }
        });

    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        Log.d("onActivityResult()", Integer.toString(resultCode));

        //final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);
        switch (requestCode)
        {
            case REQUEST_LOCATION:
                switch (resultCode)
                {
                    case Activity.RESULT_OK:
                    {
                        // All required changes were successfully made
                        Toast.makeText(getActivity(), "Location enabled by user!", Toast.LENGTH_LONG).show();
                        break;
                    }
                    case Activity.RESULT_CANCELED:
                    {
                        // The user was asked to change settings, but chose not to
                        Toast.makeText(getActivity(), "Location not enabled, user cancelled.", Toast.LENGTH_LONG).show();
                        break;
                    }
                    default:
                    {
                        break;
                    }
                }
                break;
        }
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {

    }

}

以下是视觉结果，如果位置模式被禁用，则首先显示对话框:

然后，如果用户点击否，结果会从 Activity 传递到 Fragment，其中显示一个 Toast:

当用户点击是，但结果是成功，并且启用了定位模式时，情况相同:

请注意，最好将所有这些功能保留在 Activity 中，然后在结果到来时调用 Fragment 中的公共(public)方法。

这是用于在 Activity 中保留功能的完整工作代码。当然，在这个解决方案中，您需要在调用 onActivityResult() 之后，在 Fragment 中添加一个调用来更新 Location Mode 的状态。

public class MainActivity extends AppCompatActivity
        implements GoogleApiClient.ConnectionCallbacks,
        GoogleApiClient.OnConnectionFailedListener {


    LocationRequest mLocationRequest;
    GoogleApiClient mGoogleApiClient;
    PendingResult<LocationSettingsResult> result;
    final static int REQUEST_LOCATION = 199;

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

        mGoogleApiClient = new GoogleApiClient.Builder(this)
                .addApi(LocationServices.API)
                .addConnectionCallbacks(this)
                .addOnConnectionFailedListener(this).build();
        mGoogleApiClient.connect();

    }

    @Override
    public void onConnected(Bundle bundle) {

        mLocationRequest = LocationRequest.create();
        mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
        mLocationRequest.setInterval(30 * 1000);
        mLocationRequest.setFastestInterval(5 * 1000);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(mLocationRequest);
        builder.setAlwaysShow(true);

        result = LocationServices.SettingsApi.checkLocationSettings(mGoogleApiClient, builder.build());

        result.setResultCallback(new ResultCallback<LocationSettingsResult>() {
            @Override
            public void onResult(LocationSettingsResult result) {
                final Status status = result.getStatus();
                //final LocationSettingsStates state = result.getLocationSettingsStates();
                switch (status.getStatusCode()) {
                    case LocationSettingsStatusCodes.SUCCESS:
                        // All location settings are satisfied. The client can initialize location
                        // requests here.
                        //...
                        break;
                    case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
                        // Location settings are not satisfied. But could be fixed by showing the user
                        // a dialog.
                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            status.startResolutionForResult(
                                    MainActivity.this,
                                    REQUEST_LOCATION);
                        } catch (SendIntentException e) {
                            // Ignore the error.
                        }
                        break;
                    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.
                        //...
                        break;
                }
            }
        });

    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data)
    {
        Log.d("onActivityResult()", Integer.toString(resultCode));

        //final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);
        switch (requestCode)
        {
            case REQUEST_LOCATION:
                switch (resultCode)
                {
                    case Activity.RESULT_OK:
                    {
                        // All required changes were successfully made
                        Toast.makeText(MainActivity.this, "Location enabled by user!", Toast.LENGTH_LONG).show();
                        break;
                    }
                    case Activity.RESULT_CANCELED:
                    {
                        // The user was asked to change settings, but chose not to
                        Toast.makeText(MainActivity.this, "Location not enabled, user cancelled.", Toast.LENGTH_LONG).show();
                        break;
                    }
                    default:
                    {
                        break;
                    }
                }
                break;
        }
    }

    @Override
    public void onConnectionSuspended(int i) {

    }

    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {

    }
}