java - 将字符串从一个类发送到一个 Activity

Question

我的应用程序使用地理围栏在输入位置时通知用户，当用户输入该位置时会显示通知。 我试图做的是让触发地理围栏将它们转换为字符串，然后将它们发送到另一个 Activity ，以便它们可以显示在 ListView 中。 我已经在线观看了有关如何制作 ListView 以及如何使用 Intent 发送数据的教程，但我尝试做的事情似乎不起作用。

编辑 我正在使用另一个类 MainActivity 中的 startActivity Intent 来启动 ListView PageActivity。

目标

如果用户从任何地方(尤其是从应用程序外部)单击通知，它将打开应用程序，并在 ListView 中填充地理围栏详细信息。如果用户打开应用程序只是从启动器打开应用程序，那么也会发生同样的情况。该列表将填充任何已触发的地理围栏。

GeofenceTransitionsIntentService 类:

public class GeofenceTransitionsIntentService extends IntentService {

    protected static final String TAG = "GeofenceTransitionsIS";



    /**
     * This constructor is required, and calls the super IntentService(String)
     * constructor with the name for a worker thread.
     */
    public GeofenceTransitionsIntentService() {
        // Use the TAG to name the worker thread.
        super(TAG);
    }


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

    /**
     * Handles incoming intents.
     * @param intent sent by Location Services. This Intent is provided to Location
     *               Services (inside a PendingIntent) when addGeofences() is called.
     */
    @Override
    protected void onHandleIntent(Intent intent) {

        GeofencingEvent geofencingEvent = GeofencingEvent.fromIntent(intent);
        if (geofencingEvent.hasError()){
            String errorMessage = GeofenceErrorMessages.getErrorString(this,
                    geofencingEvent.getErrorCode());
            Log.e(TAG, errorMessage);
            return;
        }

        // Get the Transistion Type
        int geofenceTransition = geofencingEvent.getGeofenceTransition();

        // Test that the reported transisition was of interest.
        if (geofenceTransition == Geofence.GEOFENCE_TRANSITION_ENTER ||
                geofenceTransition == Geofence.GEOFENCE_TRANSITION_EXIT) {

            // Get the geofences that were triggered. A single event can trigger multiple geofences.
            List<Geofence> triggeringGeofences = geofencingEvent.getTriggeringGeofences();

            // Get the transistion details as a String.
            String geofenceTransitionDetails = getGeofenceTransitionDetails(
                    this,
                    geofenceTransition,
                    triggeringGeofences
            );


            headsUpSmsNotifaction(geofenceTransitionDetails);


            Intent i = new Intent(this, listPageActivty.class);
            i.putExtra("intentKey",geofenceTransitionDetails);



            Log.i(TAG, geofenceTransitionDetails);
        } else{
            // Log the error
            Log.e(TAG, getString(R.string.geofence_transition_invalid_type, geofenceTransition));

        }

    }


    /**
     * Gets transition details and returns them as a formatted string.
     *
     * @param context               The app context.
     * @param geofenceTransition    The ID of the geofence transition.
     * @param triggeringGeofences   The geofence(s) triggered.
     * @return                      The transition details formatted as String.
     */

    private String getGeofenceTransitionDetails(Context context, int geofenceTransition, List<Geofence> triggeringGeofences) {
        String geofenceTransitionString = getTransitionString(geofenceTransition);

        // Get the Ids of each geofence that was triggered.
        ArrayList triggeringGeofencesIdsList = new ArrayList();
        for (Geofence geofence : triggeringGeofences) {
            triggeringGeofencesIdsList.add(geofence.getRequestId());
        }

        String triggeringGeofencesIdsString = TextUtils.join(", ", triggeringGeofencesIdsList);


        return  geofenceTransitionString + ": "  + triggeringGeofencesIdsString;
    }

    /**
     * Posts a notification in the notification bar when a transition is detected.
     * If the user clicks the notification, control goes to the MainActivity.
     */


    private void headsUpSmsNotifaction(String notificationDetails){

        // Create an explicit content Intent that starts the main Activity.
        Intent notificationIntent = new Intent(this, sendSmsReceiver.class);
        PendingIntent notificationPendingIntent = PendingIntent.getBroadcast(this,44,notificationIntent,0);

        Calendar calendar = Calendar.getInstance();
        SimpleDateFormat mdfromat = new SimpleDateFormat("hh:ss | dd/ MM / yyyy");
        String strDate = mdfromat.format(calendar.getTime());



        // Get a notification builder that's compatible with platform versions >= 4
        NotificationCompat.Builder builder = new NotificationCompat.Builder(this);

        // Define the notification settings.
        builder.setSmallIcon(R.mipmap.ic_launcher)
                // In a real app, you may want to use a library like Volley
                // to decode the Bitmap.
                .setLargeIcon(BitmapFactory.decodeResource(getResources(),
                        R.mipmap.ic_launcher))
                .setColor(Color.RED)
                .setPriority(NotificationCompat.PRIORITY_MAX)
                .setVibrate(new long[]{10,10,10})
                .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
                .setContentTitle(notificationDetails)
                .setContentText(strDate)
                .addAction(R.mipmap.ic_launcher,"send",notificationPendingIntent)

                .setContentIntent(notificationPendingIntent);


        // Dismiss notification once the user touches it.
        //builder.setAutoCancel(true);

        // Get an instance of the Notification manager
        NotificationManager mNotificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);

        // Issue the notification
        mNotificationManager.notify(0, builder.build());
    }



    /**
     * Maps geofence transition types to their human-readable equivalents.
     *
     * @param transitionType    A transition type constant defined in Geofence
     * @return                  A String indicating the type of transition
     */

    private String getTransitionString(int transitionType) {
        switch (transitionType) {
            case Geofence.GEOFENCE_TRANSITION_ENTER:
                return getString(R.string.geofence_transition_entered);
            case Geofence.GEOFENCE_TRANSITION_EXIT:
                return getString(R.string.geofence_transition_exited);
            default:
                return getString(R.string.unknown_geofence_transition);
        }

    }
}

listPageActivty 类:

public class listPageActivty extends AppCompatActivity {

    ListView listView;
    String[] ListElements = new String[]{"Android","PHP"};
    String item = "one";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list_page_activty);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);


        listView = (ListView) findViewById(R.id.listView2);
        Button addBtn = (Button) findViewById(R.id.addBtn);

        final List<String> ListElementsArrayList = new ArrayList<String>(Arrays.asList(ListElements));
        final ArrayAdapter<String> adapter = new ArrayAdapter<String>(listPageActivty.this,android.R.layout.simple_list_item_1,ListElementsArrayList);

        listView.setAdapter(adapter);

      Bundle bundleData = getIntent().getExtras();
        if (bundleData == null){
            return;
        }

        String intentItem = bundleData.getString("intentKey");
        ListElementsArrayList.add(intentItem);


        addBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                ListElementsArrayList.add(item);
                adapter.notifyDataSetChanged();
            }
        });


    }

}

非常感谢任何帮助，谢谢。

Answer 1

你必须改变这个:

Intent i = new Intent(this, listPageActivty.class);
i.putExtra("intentKey",geofenceTransitionDetails);

对此:

Intent i = new Intent(this, listPageActivty.class);
i.putExtra("intentKey",geofenceTransitionDetails);
this.startActivity(i);

我认为您刚刚离开了startActivity()

在另一个Activity中，您将获得如下值:

String GeoTransitionDetails = getIntent().getExtras().getString("intentKey");