我已经编写了以下通知代码，我能够看到通知和通知的标题，但是正文内容不可见。我尝试过多次使用静态值，但仍然无法找出问题所在。请帮我一下，提前致谢。
private void messagenotification(String msg, String nextid) {
SharedPreferences settings = getSharedPreferences(PREFS_NAME, 0);
SharedPreferences.Editor editor = settings.edit();
editor.putString("id", nextid ).apply();
Intent intent = new Intent(this, NextActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
PendingIntent pendingIntent = PendingIntent.getActivity(this, 0 /* Request code */, intent,
PendingIntent.FLAG_ONE_SHOT);
Uri defaultSoundUri = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
NotificationCompat.Builder notificationBuilder = (NotificationCompat.Builder) new NotificationCompat.Builder(this)
.setSmallIcon(R.mipmap.blue)
.setLargeIcon(BitmapFactory.decodeResource(getResources(), R.mipmap.blue))
.setContentTitle("Chat")
.setStyle(new NotificationCompat.BigTextStyle().bigText(msg))
.setAutoCancel(true)
.setSound(defaultSoundUri)
.setContentIntent(pendingIntent);
NotificationManager notificationManager =
(NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
notificationManager.notify(0 /* ID of notification */, notificationBuilder.build());
}