NotificationUtil 通知工具类

public class NotificationUtil {
    private static final String TAG = AppConstants.APP_TAG + "NotificationUtil ";
    private static volatile NotificationUtil mInstance;
    private static Context mContext = MyApplication.getAppContext();

    public NotificationUtil() {
    }

    /**
     * get Instance.
     *
     * @return instance.
     */
    public static NotificationUtil getInstance() {
        if (mInstance == null) {
            synchronized (NotificationUtil.class) {
                if (mInstance == null) {
                    mInstance = new NotificationUtil();
                }
            }
        }
        return mInstance;
    }

    public void showNotification(int notificationId) {
        LogUtil.d(TAG + "testNotification*");
        RemoteViews views = new RemoteViews(mContext.getPackageName(), R.layout.layout_surprise_notification);//自定义的布局视图
        //RemoteViews views = new RemoteViews(mContext.getPackageName(), R.layout.view_notification_layout);//自定义的布局视图

        //按钮点击事件：
        int requestCode = 1;
        PendingIntent seeIntent = PendingIntent.getBroadcast(mContext, requestCode, new Intent(
            AppConstants.NOTIFICATION_ACTION_SEE), PendingIntent.FLAG_UPDATE_CURRENT);
        PendingIntent ignoreIntent = PendingIntent.getBroadcast(mContext, requestCode, new Intent(
            AppConstants.NOTIFICATION_ACTION_IGNORE), PendingIntent.FLAG_UPDATE_CURRENT);
        views.setOnClickPendingIntent(R.id.btn_see, seeIntent);//
        views.setOnClickPendingIntent(R.id.btn_ignore, ignoreIntent);//
        //创建通知：
        String id = "channel_001";
        String name = "name";
        NotificationManager notificationManager = (NotificationManager) mContext.getSystemService(NOTIFICATION_SERVICE);
        Notification notification = null;
        notification = new Notification.Builder(mContext, id)
//            .setChannelId(id)
//            .setContentTitle("活动")
//            .setContentText("您有一项新活动")
            .setCustomBigContentView(views)
            .setCustomContentView(views)
            //.setContent(views)//设置布局
            .setLargeIcon(BitmapFactory.decodeResource(mContext.getResources(), R.mipmap.ic_launcher))
            .setSmallIcon(R.mipmap.ic_launcher).build();

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel mChannel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_LOW);
            notificationManager.createNotificationChannel(mChannel);
        }
        notificationManager.notify(notificationId, notification);

    }
}

notificationId每次调用会创建一个新的通知

在 requestcode 值一样的情况下 FLAG_UPDATE_CURRENT会更新之前PendingIntent的消息，FLAG_CANCEL_CURRENT 会取消之前的PendingIntent的消息
因此：只有 notificationId和requestcode每次都不同的情况下，才可以每次创建新的消息且可以接收对应的PendingIntent的消息