Android-貪喫蛇（三）- Mainactivity

package com.example.administrator.eatingjj;

import android.media.MediaPlayer;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.WindowManager;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
    MediaPlayer mediaPlayer1;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //設置成無狀態欄
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        setContentView(R.layout.activity_main);

        //播放背景音樂
        mediaPlayer1 = null;
        mediaPlayer1 = MediaPlayer.create(this, R.raw.snake);
        mediaPlayer1.start();

        //設置循環播放
        mediaPlayer1.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
            @Override
            public void onCompletion(MediaPlayer mp) {
                mediaPlayer1.start();
                mediaPlayer1.setLooping(true);
            }
        });
    }


    //實現再按一次退出程序
    private long exitTime = 0;
    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_BACK && event.getAction() == KeyEvent.ACTION_DOWN){
            if((System.currentTimeMillis()-exitTime) > 2000){
                Toast.makeText(getApplicationContext(), "再按一次退出程序", Toast.LENGTH_SHORT).show();
                exitTime = System.currentTimeMillis();
            } else {
                finish();
                System.exit(0);
            }
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }
}