Android 通知栏的使用方法

	//CHANNEL_ID，渠道ID，Android 8.0及更高版本必须要设置
    NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
    		//设置小图标
            .setSmallIcon(R.drawable.notification_icon)
            //设置标题
            .setContentTitle(textTitle)
            //设置内容
            .setContentText(textContent)
            //设置等级
            .setPriority(NotificationCompat.PRIORITY_DEFAULT);

    private void createNotificationChannel() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            CharSequence name = getString(R.string.channel_name);
            String description = getString(R.string.channel_description);
            //不同的重要程度会影响通知显示的方式
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
            channel.setDescription(description);

            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }

	//点击时想要打开的界面
    Intent intent = new Intent(this, AlertDetails.class);
    //一般点击通知都是打开独立的界面，为了避免添加到现有的activity栈中，可以设置下面的启动方式
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
    //创建activity类型的pendingIntent，还可以创建广播等其他组件
    PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);

    NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
            .setSmallIcon(R.drawable.notification_icon)
            .setContentTitle("My notification")
            .setContentText("Hello World!")
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            //设置pendingIntent
            .setContentIntent(pendingIntent)
            //设置点击后是否自动消失
            .setAutoCancel(true);    

    NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
    //notificationId 相当于通知的唯一标识，用于更新或者移除通知
    notificationManager.notify(notificationId, builder.build());