两个推送通知未显示

Question

我目前正在尝试在我的应用中推送通知。 我有2个带有通知的AsyncTask，但是在我的日志中同时执行两个时，第二个只显示a，但是当我评论第二个时，第一个显示我知道我的api工作正常

第一个异步任务：

public class backWorkerNotifTom extends AsyncTask<String,String,String> {
Context context;
String result;
String[] BookTittle;
    public  backWorkerNotifTom(Context context){this.context = context;}
    @Override
    protected String doInBackground(String... params) {
        String type = params[0];
        String NotifTomURL = "http://192.168.254.120/LibrayAPI/SelectNotifTom.php";
        if (type.equals("SelectNotifTom")){
            String dateTom = params[1];
            String borrowerID = params[2];

            try {
                String data = URLEncoder.encode("date_tom","UTF-8") + "=" +
                        URLEncoder.encode(dateTom,"UTF-8");
                data += "&" + URLEncoder.encode("borrower_id","UTF-8") + "=" +
                        URLEncoder.encode(borrowerID,"UTF-8");

                URL url = new URL(NotifTomURL);
                URLConnection urlConnection = url.openConnection();
                urlConnection.setDoOutput(true);

                OutputStreamWriter outputStreamWriter = new OutputStreamWriter(urlConnection.getOutputStream());
                outputStreamWriter.write(data);
                outputStreamWriter.flush();

                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));

                StringBuilder sb = new StringBuilder();
                String line;

                while ((line = bufferedReader.readLine())!= null){
                    sb.append(line+"\n");
                }
                result = sb.toString();

                JSONArray jsonArray = new JSONArray(result);
                JSONObject jsonObject;
                BookTittle = new String[jsonArray.length()];
                for (int i = 0; i < jsonArray.length(); i++) {
                    jsonObject = jsonArray.getJSONObject(i);
                    BookTittle[i] = jsonObject.getString("BookTittle");
                    // PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, new Intent(context, NotifList.class), 0);
                    NotificationCompat.Builder mbuilder = new NotificationCompat.Builder(context)
                            .setSmallIcon(R.drawable.ic_book_black_24dp)
                            .setContentTitle("Library Alert")
                            .setContentText("Tommorow is the Due Day of the Book " + BookTittle[i] + " You Borrowed")

                            //.setContentIntent(pendingIntent)
                            .setTicker("Notifications");

                    NotificationManager notificationManager = (NotificationManager) context.getSystemService(context.NOTIFICATION_SERVICE);

                    if (notificationManager != null) {
                        notificationManager.notify(i, mbuilder.build());
                    }
                }
            }
            catch (Exception ex){
                ex.printStackTrace();

            }


        }
        return result;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);

    }
}

第二个异步任务：

public class backWorkerNotif extends AsyncTask<String, String, String> {
    String result = null;
    String[] BookTittle;
   Context context;
   public  backWorkerNotif(Context context){this.context = context;}

    @Override
    protected String doInBackground(String... params) {
        String selectNotif_url = "http://192.168.254.120/LibrayAPI/SelectNotif.php";
        String type = params[0];

        if (type.equals("Notif")) {
            String DateNow = params[1];
            String BorrowerID = params[2];
            try {

                String data = URLEncoder.encode("date_now", "UTF-8") + "=" +
                        URLEncoder.encode(DateNow, "UTF-8");
                data += "&" + URLEncoder.encode("borrower_id", "UTF-8") + "=" +
                        URLEncoder.encode(BorrowerID, "UTF-8");

                URL url = new URL(selectNotif_url);
                URLConnection urlConnection = url.openConnection();
                urlConnection.setDoOutput(true);

                OutputStreamWriter outputStreamWriter = new OutputStreamWriter(urlConnection.getOutputStream());

                outputStreamWriter.write(data);
                outputStreamWriter.flush();

                BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(urlConnection.getInputStream()));
                StringBuilder sb = new StringBuilder();
                String line;
                while ((line = bufferedReader.readLine()) != null) {

                    sb.append(line + "\n");
                }
                result = sb.toString();
                if (result.isEmpty()) {
                } else {
                    //Json

                    JSONArray jsonArray = new JSONArray(result);
                    JSONObject jsonObject;
                    BookTittle = new String[jsonArray.length()];
                    for (int i = 0; i < jsonArray.length(); i++) {
                        jsonObject = jsonArray.getJSONObject(i);
                        BookTittle[i] = jsonObject.getString("BookTittle");
                       // PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, new Intent(context, NotifList.class), 0);
                        NotificationCompat.Builder mbuilder = new NotificationCompat.Builder(context)
                                .setSmallIcon(R.drawable.ic_book_black_24dp)
                                .setContentTitle("Library notification")
                                .setContentText("Today is the Due Day of the Book " + BookTittle[i] + " You Borrowed")

                                //.setContentIntent(pendingIntent)
                                .setTicker("Notification Alert");

                        NotificationManager notificationManager = (NotificationManager) context.getSystemService(context.NOTIFICATION_SERVICE);

                        if (notificationManager != null) {
                            notificationManager.notify(i, mbuilder.build());
                        }
                    }
                }
            }
            catch (Exception ex) {
                ex.printStackTrace();

            }


        }

        return null;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected void onPostExecute(String jsonArray) {
        super.onPostExecute(jsonArray);

    }
}

登录课程

public class Login extends AppCompatActivity {

    EditText username,password;

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

        username = findViewById(R.id.edtUsername);
        password = findViewById(R.id.edtPassword);
    }

    public void onLogin(View view) {

        String Username = username.getText().toString();
        String Password = password.getText().toString();
        //notif call
        //call notif for overdue tommorow
        backWorkerNotifTom backWorkerNotifTom = new backWorkerNotifTom(this);
      //get datetime tom
       Calendar calendar =  Calendar.getInstance();
        calendar.add(Calendar.DAY_OF_YEAR,1);
        Date dateTom = calendar.getTime();
        SimpleDateFormat sf1 = new SimpleDateFormat("yyyy-MM-dd");
        String dateTomString = sf1.format(dateTom);
        Toast.makeText(this, dateTomString, Toast.LENGTH_SHORT).show();
        backWorkerNotifTom.execute("SelectNotifTom",dateTomString,Username);

        backWorkerNotif backWorkerNotif = new backWorkerNotif(this);
        Date date = Calendar.getInstance().getTime();
        SimpleDateFormat SF = new SimpleDateFormat("yyyy-MM-dd");
        String DateNow = SF.format(date);
        backWorkerNotif.execute("Notif", DateNow, Username);

        String Type = "login";
        GlobalVariable.BorrowerID = Username;
        GlobalVariable.Password = Password;
        backgroundWorker _backgroundWorker = new backgroundWorker(this);
        _backgroundWorker.execute(Type, Username, Password);


    }
}

Answer 1

这可能是由于您在进行两种通知时使用的ID相同而发生的。 这将导致第二个覆盖第一个。 如果要显示多个通知，则每个通知都需要一个单独的ID。

有问题的代码行是notificationManager.notify(i, mbuilder.build()); 在两个异步任务中。 因为“ i”是作为一个整数值创建的，其长度范围为0，所以两个任务之间会出现很多冲突。 您需要确保每个通知使用唯一的ID