안드로이드 기존잠금화면을 불러오는 것을 만드는데 문제가 생겨서 질문드립니다.

Question

public class MainActivity extends FragmentActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        getWindow().addFlags(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
        | WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD);
    }

    @Override
    public void onBackPressed() { //뒤로가기
        //super.onBackPressed();
    }
    @Override
    public void onUserLeaveHint(){
        Toast.makeText(this,"홈버튼",Toast.LENGTH_SHORT).show();

        finish();
        Intent i = new Intent(this, MainActivity.class);
        i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        startActivity(i);

        super.onUserLeaveHint();
    }

}

MainActivity 클래스입니다. 여기서는 오류가 안납니다.

public class ScreenReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        if(intent.getAction().equals(Intent.ACTION_SCREEN_OFF)){
            Intent i = new Intent(context, MainActivity.class);
            i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(i);
        }
    }
} ScreenReceiver 클래스입니다. 여기서는 오류는 안납니다.

public class ScreenService extends Service {
    private ScreenReceiver mReceiver = null;
    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate(){
        super.onCreate();

        mReceiver = new ScreenReceiver();
        IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
        registerReceiver(mReceiver, filter);

    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId){
        super.onStartCommand(intent, flags, startId);

        if(intent != null){
            if(intent.getAction()==null){
                if(mReceiver==null){
                    mReceiver = new ScreenReceiver();
                    IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
                    registerReceiver(mReceiver, filter);
                }
            }
        }
        return START_REDELIVER_INTENT;
    }

    @Override
    public void onDestroy() {

        super.onDestroy();


        if (mReceiver != null) {

            unregisterReceiver(mReceiver);

        }
    }
}
 ScreenService 클래스입니다. 여기서는 오류는 안납니다.

package com.example.sw.myapplication1;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

/**
 * Created by 창우 on 2016-03-31.
 */
public class ConfigActivity extends Activity{

    private Button onBtn, offBtn;



    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        onBtn= (Button)findViewById(R.id.btn1);

        offBtn= (Button)findViewById(R.id.btn2);




        onBtn.setOnClickListener(new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                Intent intent = new Intent(this, ScreenService.class);

                startService(intent);

            }
        });

                offBtn.setOnClickListener(new View.OnClickListener() {
                    @Override
                    public void onClick(View v) {

                        Intent intent = new Intent(this, ScreenService.class);
                        stopService(intent);
                    }
                });
    }
}

문제가 되는 ConfigActivity 클래스인데요 여기서 각 버튼에 대한 처리부분에서 Intent intent = new Intent ~~ 이부분이 오류가 납니다.