我已尝试连接到 Nearby Messages API，并已成功订阅。
现在，由于某种原因，我的 mMessageListener 字段永远不会收到回调。我已经使用 Android 信标服务演示应用程序使用邻近信标 api 配置了我的信标。
public class MainActivity extends AppCompatActivity implements
GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener {
// Declaration of member variables
private GoogleApiClient mGoogleApiClient;
private final String TAG = "Bridge.MainActivity";
private boolean mResolvingError = false;
private static final int REQUEST_RESOLVE_ERROR = 100;
private static final int REQUEST_PERMISSION = 42;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Initializing the Google API client
}
private MessageListener mMessageListener = new MessageListener() {
@Override
public void onFound(Message message) {
// Do something with the message
Log.i(TAG, " Found Message : " + message.toString());
}
@Override
public void onLost(Message message) {
super.onLost(message);
Log.i(TAG, " Found Message : " + message.toString());
}
};
@Override
public void onConnected(@Nullable Bundle bundle) {
Log.d(TAG, "GoogleAPi Client Connected");
foregorundSubscribeBeacons();
}
@Override
public void onConnectionSuspended(int i) {
Log.d(TAG, "Google Api Connection Suspended : " + i);
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
Log.d(TAG, "GoogleApi Connection failed : " + connectionResult.getErrorMessage());
}
public void foregorundSubscribeBeacons() {
// Subscribe to receive messages
Log.i(TAG, "Trying to subscribe");
if (!mGoogleApiClient.isConnected()) {
if (!mGoogleApiClient.isConnecting()) {
mGoogleApiClient.connect();
}
} else {
SubscribeOptions options = new SubscribeOptions.Builder()
.setStrategy(Strategy.BLE_ONLY)
.setCallback(new SubscribeCallback() {
@Override
public void onExpired() {
Log.i(TAG, "No longer subscribing.");
}
}).build();
Nearby.Messages.subscribe(mGoogleApiClient, mMessageListener, options)
.setResultCallback(new ResultCallback<Status>() {
@Override
public void onResult(Status status) {
if (status.isSuccess()) {
Log.i(TAG, "Subscribed successfully.");
} else {
Log.i(TAG, "Could not subscribe.");
// Check whether consent was given;
// if not, prompt the user for consent.
handleUnsuccessfulNearbyResult(status);
}
}
});
}
}
private void handleUnsuccessfulNearbyResult(Status status) {
Log.i(TAG, "Processing error, status = " + status);
if (mResolvingError) {
// Already attempting to resolve an error.
return;
} else if (status.hasResolution()) {
try {
mResolvingError = true;
status.startResolutionForResult(this,
REQUEST_RESOLVE_ERROR);
} catch (IntentSender.SendIntentException e) {
mResolvingError = false;
Log.i(TAG, "Failed to resolve error status.", e);
}
} else {
if (status.getStatusCode() == CommonStatusCodes.NETWORK_ERROR) {
Toast.makeText(this.getApplicationContext(),
"No connectivity, cannot proceed. Fix in 'Settings' and try again.",
Toast.LENGTH_LONG).show();
} else {
// To keep things simple, pop a toast for all other error messages.
Toast.makeText(this.getApplicationContext(), "Unsuccessful: " +
status.getStatusMessage(), Toast.LENGTH_LONG).show();
}
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_RESOLVE_ERROR) {
// User was presented with the Nearby opt-in dialog and pressed "Allow".
mResolvingError = false;
if (resultCode == RESULT_OK) {
// Execute the pending subscription and publication tasks here.
foregorundSubscribeBeacons();
} else if (resultCode == RESULT_CANCELED) {
// User declined to opt-in. Reset application state here.
} else {
Toast.makeText(this, "Failed to resolve error with code " + resultCode,
Toast.LENGTH_LONG).show();
}
}
}
@Override
protected void onStart() {
super.onStart();
//Initiate connection to Play Services
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(Nearby.MESSAGES_API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
mGoogleApiClient.connect();
//The location permission is required on API 23+ to obtain BLE scan results
int result = ActivityCompat
.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION);
if (result != PackageManager.PERMISSION_GRANTED) {
//Ask for the location permission
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.ACCESS_COARSE_LOCATION},
REQUEST_PERMISSION);
}
}
@Override
protected void onStop() {
super.onStop();
//Tear down Play Services connection
if (mGoogleApiClient.isConnected()) {
Log.d(TAG, "Un-subscribing…");
mGoogleApiClient.disconnect();
}
}