ndroid 8.0中修改NotificationChannel 属性，升级app后该修改不生效，必须卸载app重新安装才能生效，原代码如下：
1.public void notifyDownloading(long progress, long num, String file_name) { Notification.Builder mBuilder; mBuilder = new Notification.Builder(MainActivity.this, TAG ); NotificationChannel channel; channel = new NotificationChannel(TAG , file_name, NotificationManager.IMPORTANCE_LOW); mNotifyManager.createNotificationChannel(channel); mBuilder.setSmallIcon(R.drawable.notification_download_icon); mBuilder.setProgress((int) num, (int) progress, false); mBuilder.setContentInfo(getPercent((int) progress, (int) num)); mBuilder.setOngoing(true); mBuilder.setWhen(System.currentTimeMillis()); mBuilder.setContentTitle(file_name); mBuilder.setContentText("download"); PendingIntent pendIntent = PendingIntent.getActivity( MainActivity.this, NOTIFY_ID, getCurActivityIntent(), PendingIntent.FLAG_UPDATE_CURRENT); mBuilder.setContentIntent(pendIntent); mNotifyManager.notify(NOTIFY_ID, mBuilder.build()); }
这里将IMPORTANCE_HIGH修改为IMPORTANCE_LOW，通过Android Studio直接安装，发现修改不生效，app的效果还是IMPORTANCE_HIGH属性的效果。总之，一脸懵逼。。。
经过若干猜测和尝试，发现修改每次创建Notification.Builder的id和NotificationChannel的id就可以规避该问题，修改后代码如下：
public void notifyDownloading(long progress, long num, String file_name) { Notification.Builder mBuilder; mBuilder = new Notification.Builder(MainActivity.this, TAG + System.currentTimeMillis()); NotificationChannel channel; channel = new NotificationChannel(TAG + System.currentTimeMillis(), file_name, NotificationManager.IMPORTANCE_LOW); mNotifyManager.createNotificationChannel(channel); mBuilder.setSmallIcon(R.drawable.notification_download_icon); mBuilder.setProgress((int) num, (int) progress, false); mBuilder.setContentInfo(getPercent((int) progress, (int) num)); mBuilder.setOngoing(true); mBuilder.setWhen(System.currentTimeMillis()); mBuilder.setContentTitle(file_name); mBuilder.setContentText("download"); PendingIntent pendIntent = PendingIntent.getActivity( MainActivity.this, NOTIFY_ID, getCurActivityIntent(), PendingIntent.FLAG_UPDATE_CURRENT); mBuilder.setContentIntent(pendIntent); mNotifyManager.notify(NOTIFY_ID, mBuilder.build()); }
通过System.currentTimeMillis()保证每次创建对象的Id不同。