如何在不点击的情况下获取GCM通知可选数据?当应用程序在后台运行时

Question

当在后台收到GCM通知时，当用户单击该通知时，它将链接到我的应用程序，然后我可以在此GCM通知中获取数据包。

但是有没有办法在不单击通知的情况下获取通知中的数据？ 比如，如果通知来了，用户不点击通知，而是点击应用，直接打开应用。此时，是否可以在用户打开应用程序时获取所有通知有效负载？

Answer 1

当您收到 GCM 消息时，Android 会调用您的 BroadcastReceiver，即使您的应用在后台运行：

public class GCMBroadcastReceiver extends BroadcastReceiver {   
    @Override
    public void onReceive(final Context context, Intent intent) {
        String action = intent.getAction();
        L.m("onReceive GCM called!");
        //Get your data
        String id = intent.getStringExtra("id");
        String tickerText = intent.getStringExtra("tickerText");
        String title = intent.getStringExtra("title");
        String msg = intent.getStringExtra("message");
        String dateTime = intent.getStringExtra("datetime");
        //Here, You can save your data in SQLite
        //For example: I need to save title, msg and dateTime
        DBGcmMessages dbGcmMessages = new DBGcmMessages(context);
        dbGcmMessages.insert(title, msg, dateTime);
        //Then, you can show notification or show nothing!!!
    }
}

这是DBGcmMessages内容：

public class DBGcmMessages extends SQLiteOpenHelper {
    private Context mContext;
    private SQLiteDatabase mDatabase;
    private static final String DB_NAME = "gcm_message_db";
    private static final int DB_VERSION = 1;
    private static final String TABLE = "login";
    private static final String COLUMN_ID = "_id";
    private static final String COLUMN_TITLE = "_title";
    private static final String COLUMN_TEXT = "_text";
    private static final String COLUMN_DATE_TIME = "_date_time";
    private static final String CREATE_TABLE = "CREATE TABLE " + TABLE + " (" +
            COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL," +
            COLUMN_TITLE + " nvarchar(255)," +
            COLUMN_TEXT + " text," +
            COLUMN_DATE_TIME + " nvarchar(255));";
    public DBGcmMessages(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
        mContext = context;
    }
    @Override
    public void onCreate(SQLiteDatabase db) {
        try {
            db.execSQL(CREATE_TABLE);
            L.m("Create table gcm messages successfully!");
        } catch (SQLiteException exception) {
            L.m(exception.getMessage());
        }
    }
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        try {
            L.m("upgrade table gcm message executed!");
            db.execSQL("DROP TABLE " + TABLE + " IF EXISTS;");
            onCreate(db);
        }
        catch (SQLiteException exception) {
            L.m(exception.getMessage());
        }
    }
    public void insert(String title, String text, String dateTime) {
        try {
            if (title == null || text == null) return;
            this.mDatabase = this.getWritableDatabase();
            //Insert
            String sql = "INSERT INTO " + TABLE + "(" +
                    COLUMN_TITLE + "," +
                    COLUMN_TEXT + "," +
                    COLUMN_DATE_TIME + ") VALUES (?,?,?);";
            SQLiteStatement statement = this.mDatabase.compileStatement(sql);
            statement.bindString(1, title);
            statement.bindString(2, text);
            statement.bindString(3, dateTime);
            statement.execute();
            L.m("Insert gcm message successfully!");
        }
        finally {
            if(this.mDatabase != null) this.mDatabase.close();
            this.close();
        }
    }
    public void delete(int id) {
        try {
            this.mDatabase = this.getWritableDatabase();
            this.mDatabase.execSQL("Delete from " + TABLE + " where " + COLUMN_ID + "='" + id + "'");
            L.m("Delete gcm message successfully!");
        }
        finally {
            if(this.mDatabase != null) this.mDatabase.close();
            this.close();
        }
    }
    public ArrayList<GCMMessage> getAll() {
        this.mDatabase = this.getWritableDatabase();
        Cursor result = null;
        try {
            result = this.mDatabase.rawQuery("select * from " + TABLE + " order by " + COLUMN_ID + " desc", null);
            int rows = result.getCount();
            if (rows == 0) return null;
            ArrayList<GCMMessage> messages = new ArrayList<>();
            result.moveToFirst();
            for (int i = 0; i < rows; i++) {
                int id = result.getInt(0);
                String title = result.getString(1);
                String text = result.getString(2);
                String dateTime = result.getString(3);
                messages.add(new GCMMessage(id, title, text, dateTime));
                result.moveToNext();
            }
            L.m("Get all gcm message : " + rows);
            return messages;
        } catch (Exception ex) {
            return null;
        }
        finally {
            if(result != null) result.close();
            if(this.mDatabase != null) this.mDatabase.close();
            this.close();
        }
    }
}