mNotification=new Notification(); icon怎么设置

mNotification=new Notification();
mNotification.icon=icon ; ？？？这个icon怎么设置？

 Notification notification = new NotificationCompat.Builder(context)
                 .setLargeIcon(icon).setSmallIcon(R.drawable.ic_launcher)
                 .setTicker("showNormal").setContentInfo("contentInfo")
                 .setContentTitle("ContentTitle").setContentText("ContentText")
                 .setNumber(++messageNum)
                 .setAutoCancel(true).setDefaults(Notification.DEFAULT_ALL)
                 .build();
         manager.notify(NOTIFICATION_ID_1, notification);

//设置通知在状态栏显示的图标
mNotification.icon=R.drawable.icon;