关于NotificationCompat.Builder()方法废弃解决方式

今天在学习系统通知时有一个问题就是NotificationCompat.Builder()不能只传入context还要加上一个String,但是随意加又不可以，在网上搜索后找到一篇文章有解决方法，下面是代码：

public class MainActivity extends AppCompatActivity {

    private Button sendNotice;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        sendNotice = findViewById(R.id.send_notice);
        sendNotice.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                switch(v.getId()){
                    case R.id.send_notice:
                        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
                        //高版本需要渠道
                        if(Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O){
                            //只在Android O之上需要渠道
                            NotificationChannel notificationChannel = new NotificationChannel("channelid1","channelname",NotificationManager.IMPORTANCE_HIGH);
                            //如果这里用IMPORTANCE_NOENE就需要在系统的设置里面开启渠道，通知才能正常弹出
                            manager.createNotificationChannel(notificationChannel);
                        }
                        Notification notification = new NotificationCompat.Builder(MainActivity.this,"channelid1")
                                .setContentTitle("This is content title")
                                .setContentText("This is content text")
                                .setWhen(System.currentTimeMillis())
                                .setSmallIcon(R.mipmap.ic_launcher)
                                .setLargeIcon(BitmapFactory.decodeResource(getResources(),R.mipmap.ic_launcher))
                                .build();
                        manager.notify(1,notification);
                        break;
                    default:
                        break;
                }
            }
        });
    }
}
主要解决问题的就是IF语句中的代码