java - 使用后退键返回 Android 应用程序上的主要 Activity 以查看用户分数

Question

希望我能得到一些建议。

我的程序有一个 Sprite ，当点击/单击时，屏幕上会记录分数。当游戏结束(时间用完)时，我希望用户能够按手机上的后退键返回到他们开始游戏的主/开始屏幕/Activity ，但它也会显示他们的分数(点击次数)。

我正在努力弄清楚如何让它通过按后退键返回。如果需要的话，我可以在以后计算出高分位。我只想回到开始屏幕。

更新:

我认为这可能与我的 list 有关为什么它不起作用。我尝试将“GameView”类添加到 list 中，但它不接受它。它说它没有默认构造函数。有什么想法吗？

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name="cct.mad.lab.MainMenu"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".GameActivity"
        android:label="@string/app_name" >
     </activity>
    <activity
        android:name=".GameView"
        android:label="@string/app_name" >
    </activity>

我的 GameView 代码如下:

public class GameView extends SurfaceView implements SurfaceHolder.Callback {

/* Member (state) fields   */
private GameLoopThread gameLoopThread;
private Paint paint; //Reference a paint object 
/** The drawable to use as the background of the animation canvas */
private Bitmap mBackgroundImage;
// For creating the game Sprite
private Sprite sprite;
// For recording the number of hits
private int hitCount;
// To track if a game is over
private boolean gameOver;
// To play sound
private SoundPlayer sound;

//int backButtonCount = 0;

public GameView(Context context) {
    super(context);
    // Focus must be on GameView so that events can be handled.
    this.setFocusable(true);
    // For intercepting events on the surface.
    this.getHolder().addCallback(this);
    // Background image added
    mBackgroundImage = BitmapFactory.decodeResource(this.getResources(), R.drawable.half_moon);

    //sound = new SoundPlayer(this);

}
 /* Called immediately after the surface created */
public void surfaceCreated(SurfaceHolder holder) {
    // We can now safely setup the game start the game loop.
    ResetGame();//Set up a new game up - could be called by a 'play again option'
    mBackgroundImage = Bitmap.createScaledBitmap(mBackgroundImage, getWidth(), getHeight(), true);
    gameLoopThread = new GameLoopThread(this.getHolder(), this);
    gameLoopThread.running = true;
    gameLoopThread.start();
}



// For the countdown timer
private long startTime; // Timer to count down from
private final long interval = 1 * 1000; // 1 sec interval
private CountDownTimer countDownTimer; // Reference to the class
private boolean timerRunning = false;
private String displayTime; // To display the time on the screen


//To initialise/reset game
private void ResetGame(){
    /* Set paint details */
    paint = new Paint();
    paint.setColor(Color.WHITE); 
    paint.setTextSize(20);
    sprite = new Sprite(this);
    hitCount = 0;
    // Set timer
    startTime = 10; // Start at 10s to count down
    // Create new object - convert startTime to milliseconds
    countDownTimer = new MyCountDownTimer(startTime*1000, interval);
    countDownTimer.start(); // Start the time running
    timerRunning = true;
    gameOver = false;


}

// Countdown Timer - private class
private class MyCountDownTimer extends CountDownTimer {

    public MyCountDownTimer (long startTime, long interval) {
        super(startTime, interval);
    }
    public void onFinish() {
        //displayTime = "Time is up!";
        timerRunning = false;
        countDownTimer.cancel();
        gameOver = true;
    }
    public void onTick (long millisUntilFinished) {
        displayTime = " " + millisUntilFinished / 1000;
    }
}


//This class updates and manages the assets prior to drawing - called from the Thread
public void update(){

    sprite.update();

}
/**
 * To draw the game to the screen
 * This is called from Thread, so synchronisation can be done
 */
public void doDraw(Canvas canvas) {
    //Draw all the objects on the canvas
    canvas.drawBitmap(mBackgroundImage, 0, 0, null);

    if (!gameOver) {
        sprite.draw(canvas);
        canvas.drawText("Time Remaining: " + displayTime, 35, 50, paint);
        canvas.drawText("Number of hits: " + hitCount, 250, 50, paint);
    } else
        canvas.drawText("Game Over!", 185, 100, paint);
        canvas.drawText("To go back to the main menu, press the 'back' key", 15, 150, paint);


}

//To be used if we need to find where screen was touched
public boolean onTouchEvent(MotionEvent event) {
        if (sprite.wasItTouched(event.getX(), event.getY())) {
            // This just renews the sprite for now
            sprite = new Sprite(this);
            //sound.playZapSound();
            hitCount++;

        }
    return true;
}

public void surfaceDestroyed(SurfaceHolder holder) {
    gameLoopThread.running = false;

    // Shut down the game loop thread cleanly.
    boolean retry = true;
    while(retry) {
        try {
            gameLoopThread.join();
            retry = false;
        } catch (InterruptedException e) {}
    }
}

public void getHitCount() {



}

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

}

}

我的主要 Activity 如下:

public class MainMenu extends Activity {

private static final int SCORE_REQUEST_CODE = 1;// The request code for the intent

TextView tvScore;
String score;
Intent gameIntent;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.game_start);
}

public void startGame(View v){
    gameIntent = new Intent(this,GameActivity.class);
    startActivityForResult(gameIntent, SCORE_REQUEST_CODE );  
}
/* Create Options Menu */
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main_menu, menu);
    return true;
}

// Respond to item selected on OPTIONS MENU
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle item selection
    switch (item.getItemId()) {
    //put data in Intent
    case R.id.easy:
        Toast.makeText(this, "Easy chosen", Toast.LENGTH_SHORT).show();
        return true;
    case R.id.medium:
        Toast.makeText(this, "Medium chosen", Toast.LENGTH_SHORT).show();
        return true;
    case R.id.hard:
        Toast.makeText(this, "Hard chosen", Toast.LENGTH_SHORT).show();
        return true;
    case R.id.other:
        Toast.makeText(this, "Other chosen", Toast.LENGTH_SHORT).show();
        return true;
    default:
        return super.onOptionsItemSelected(item);
    }
}

protected void onActivityResult(int requestCode, int resultCode, Intent retIntent) {
    // Check which request we're responding to
    if (requestCode == SCORE_REQUEST_CODE) {
        // Make sure the request was successful
        if (resultCode == RESULT_OK) {
            if (retIntent.hasExtra("GAME_SCORE")) {
                int scoreFromGame = retIntent.getExtras().getInt("GAME_SCORE");
                tvScore.setText(Integer.toString(scoreFromGame));
            }
        }   
    }

}


}

一如既往，我们非常感谢任何帮助。

谢谢

Answer 1

使用 onBackPressed。

@Override
public void onBackPressed() {
    Intent i= new Intent(your_present_activity.this,the_activity_you_want_to_jump_to.class);
    startActivity(i);
    finish();
}

您可以使用 newintent.putExtra(name,"key"); 将您的分数带到 Main.class 中；