android - 确定触摸通知图标的作用

Question

我有一个场景，当通知框被触摸时，我想将通知框中显示的消息显示到新屏幕。我能够在手机上生成通知，但是当我触摸通知框时，我无法显示该通知消息，而是显示了一些旧消息。有人可以帮我吗？

下面是我要开始的 Activity 的代码:

public class MainActivity extends Activity {
// label to display gcm messages
TextView lblMessage;

// Asyntask
AsyncTask<Void, Void, Void> mRegisterTask;

// Alert dialog manager
AlertDialogManager alert = new AlertDialogManager();

// Connection detector
ConnectionDetector cd;

public static String name;
public static String email;

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

    cd = new ConnectionDetector(getApplicationContext());

    // Check if Internet present
    if (!cd.isConnectingToInternet()) {
        // Internet Connection is not present
        alert.showAlertDialog(MainActivity.this,
                "Internet Connection Error",
                "Please connect to working Internet connection", false);
        // stop executing code by return
        return;
    }

    // Getting name, email from intent
    Intent i = getIntent();

    name = i.getStringExtra("name");
    email = i.getStringExtra("email");      

    // Make sure the device has the proper dependencies.
    GCMRegistrar.checkDevice(this);

    // Make sure the manifest was properly set - comment out this line
    // while developing the app, then uncomment it when it's ready.
    GCMRegistrar.checkManifest(this);

    lblMessage = (TextView) findViewById(R.id.lblMessage);
    lblMessage.setText("");
    String previous=i.getStringExtra("previous message");
    if(!previous.equals("The Very Beginning"))
    lblMessage.setText(previous);
    registerReceiver(mHandleMessageReceiver, new IntentFilter(
            DISPLAY_MESSAGE_ACTION));

    // Get GCM registration id
    final String regId = GCMRegistrar.getRegistrationId(this);

    // Check if regid already presents
    if (regId.equals("")) {
        // Registration is not present, register now with GCM           
        GCMRegistrar.register(this, SENDER_ID);
    } else {
        // Device is already registered on GCM
        if (GCMRegistrar.isRegisteredOnServer(this)) {
            // Skips registration.
            if(previous.equals("The Very Beginning"))
            Toast.makeText(getApplicationContext(), "Already registered with GCM", Toast.LENGTH_LONG).show();
            Log.v("Reg ID", regId);
        } else {
            // Try to register again, but not in the UI thread.
            // It's also necessary to cancel the thread onDestroy(),
            // hence the use of AsyncTask instead of a raw thread.
            final Context context = this;
            mRegisterTask = new AsyncTask<Void, Void, Void>() {

                @Override
                protected Void doInBackground(Void... params) {
                    // Register on our server
                    // On server creates a new user
                    ServerUtilities.register(context, name, email, regId);
                    return null;
                }

                @Override
                protected void onPostExecute(Void result) {
                    mRegisterTask = null;
                }

            };
            mRegisterTask.execute(null, null, null);
        }
    }
}       

/**
 * Receiving push messages
 * */
private final BroadcastReceiver mHandleMessageReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
        String newMessage = intent.getExtras().getString(EXTRA_MESSAGE);
        // Waking up mobile if it is sleeping
        WakeLocker.acquire(getApplicationContext());

        /**
         * Take appropriate action on this message
         * depending upon your app requirement
         * For now i am just displaying it on the screen
         * */

        // Showing received message
        lblMessage.setText(newMessage + "\n");          
        Toast.makeText(getApplicationContext(), "New Message: " + newMessage, Toast.LENGTH_LONG).show();

        // Releasing wake lock
        WakeLocker.release();
    }
};

@Override
protected void onDestroy() {
    if (mRegisterTask != null) {
        mRegisterTask.cancel(true);
    }
    try {
        unregisterReceiver(mHandleMessageReceiver);
        GCMRegistrar.onDestroy(this);
    } catch (Exception e) {
        Log.e("UnRegister Receiver Error", "> " + e.getMessage());
    }
    super.onDestroy();
}

}

下面是 GCM Broadcast 类的代码:

import com.google.android.gcm.GCMBaseIntentService;

public class GCMIntentService extends GCMBaseIntentService {

private static final String TAG = "GCMIntentService";

public GCMIntentService() {
    super(SENDER_ID);
}

/**
 * Method called on device registered
 **/
@Override
protected void onRegistered(Context context, String registrationId) {
    Log.i(TAG, "Device registered: regId = " + registrationId);
    displayMessage(context, "Your device registred with GCM");
    Log.d("NAME", MainActivity.name);
    ServerUtilities.register(context, MainActivity.name, MainActivity.email, registrationId);
}

/**
 * Method called on device un registred
 * */
@Override
protected void onUnregistered(Context context, String registrationId) {
    Log.i(TAG, "Device unregistered");
    displayMessage(context, getString(R.string.gcm_unregistered));
    ServerUtilities.unregister(context, registrationId);
}

/**
 * Method called on Receiving a new message
 * */
@Override
protected void onMessage(Context context, Intent intent) {
    Log.i(TAG, "Received message");
    String message = intent.getExtras().getString("message");

    displayMessage(context, message);
    // notifies user
    generateNotification(context, message);
}

/**
 * Method called on receiving a deleted message
 * */
@Override
protected void onDeletedMessages(Context context, int total) {
    Log.i(TAG, "Received deleted messages notification");
    String message = getString(R.string.gcm_deleted, total);
    displayMessage(context, message);
    // notifies user
    generateNotification(context, message);
}

/**
 * Method called on Error
 * */
@Override
public void onError(Context context, String errorId) {
    Log.i(TAG, "Received error: " + errorId);
    displayMessage(context, getString(R.string.gcm_error, errorId));
}

@Override
protected boolean onRecoverableError(Context context, String errorId) {
    // log message
    Log.i(TAG, "Received recoverable error: " + errorId);
    displayMessage(context, getString(R.string.gcm_recoverable_error,
            errorId));
    return super.onRecoverableError(context, errorId);
}

/**
 * Issues a notification to inform the user that server has sent a message.
 */
private static void generateNotification(Context context, String message) {
    int icon = R.drawable.ic_launcher;
    long when = System.currentTimeMillis();
    NotificationManager notificationManager = (NotificationManager)
            context.getSystemService(Context.NOTIFICATION_SERVICE);
    Notification notification = new Notification(icon, message, when);

    String title = context.getString(R.string.app_name);

    Intent notificationIntent = new Intent(context, MainActivity.class);
    // set intent so it does not start a new activity
    notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP |
            Intent.FLAG_ACTIVITY_SINGLE_TOP);
    //Here to
    notificationIntent.putExtra("previous message", message);
    //Here
    PendingIntent intent =
            PendingIntent.getActivity(context, 0, notificationIntent, 0);
    notification.setLatestEventInfo(context, title, message, intent);
    notification.flags |= Notification.FLAG_AUTO_CANCEL;

    // Play default notification sound
    notification.defaults |= Notification.DEFAULT_SOUND;

    //notification.sound = Uri.parse("android.resource://" + context.getPackageName() + "your_sound_file_name.mp3");

    // Vibrate if vibrate is enabled
    notification.defaults |= Notification.DEFAULT_VIBRATE;
    notificationManager.notify(0, notification);      

}

}

Answer 1

您正在使用以下标志:

FLAG_ACTIVITY_CLEAR_TOP

If set, and the activity being launched is already running in the current task, then instead of launching a new instance of that activity, all of the other activities on top of it will be closed and this Intent will be delivered to the (now on top) old activity as a new Intent.

FLAG_ACTIVITY_SINGLE_TOP

If set, the activity will not be launched if it is already running at the top of the history stack.

这意味着如果您尝试打开的 Activity 已经在运行，则不会创建新 Activity ，现有 Activity 将位于最上面。这就是为什么 onCreate 没有被执行并且没有显示新消息的原因。您可以使用不同的标志(以强制创建新 Activity )，也可以使用不同的方法(例如 onResume)更新消息。