Handler实现的打地鼠游戏

通过自定义的CountingHandler实现打地鼠小游戏，单击地鼠表示打中，并记录打中地鼠总数（地鼠一共出现10次）；

MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener,
        View.OnTouchListener {
    public static final int CODE = 10001;
    public static final int DELAY_TIME = 500;
    private TextView resultText;
    private Button beginBtn;
    private ImageView susliksImg;
    //地鼠位置的坐标
    public int[][] mPositions = new int[][]{
            {123,323},{434,234},
            {231,242},{264,111},
            {300,400},{329,111},
            {231,231},{452,427}
    };
    private int MAX_COUNT = 10;
    private int totalCount = 0;
    private int hitCount = 0;
    CountingHandler handler = new CountingHandler(this);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        resultText = (TextView) findViewById(R.id.result_txt);
        beginBtn = (Button) findViewById(R.id.star_button);
        susliksImg = (ImageView) findViewById(R.id.susliks_img);
        susliksImg.setOnTouchListener(this);
        beginBtn.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        start();
    }
    /**
     * 发送message
     */
    private void start() {
        beginBtn.setText("进行中...");
        beginBtn.setEnabled(false);
        resultText.setText("游戏开始了！");
        next(0);
    }

    /**
     * delayTime为传入的延迟时间
     */
    private void next(int delayTime) {
        int i = new Random().nextInt(mPositions.length);
        Message message = Message.obtain();
        message.what = CODE;
        message.arg1 = i;
        handler.sendMessageDelayed(message, delayTime);
        totalCount ++;
    }

    //打中地鼠响应
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        hitCount ++;
        resultText.setText("您打中了" + hitCount + "只地鼠，一共10只！");
        susliksImg.setVisibility(View.GONE);
        return false;
    }

    public static class CountingHandler extends Handler{

        public final WeakReference<MainActivity> mWeakReference;

        public CountingHandler(MainActivity activity) {
            this.mWeakReference = new WeakReference<>(activity);
        }
        //处理消息，设置地鼠的位置等。
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            //得到MainActivity弱引用
            MainActivity activity = mWeakReference.get();
            switch (msg.what){
                case CODE:
                    //判断是否打完地鼠
                    if(activity.totalCount > activity.MAX_COUNT){
                        activity.clear();
                        Toast.makeText(activity, "地鼠打完了！！", Toast.LENGTH_SHORT)
                                .show();
                        return ;
                    }
                    int i = msg.arg1;
                    activity.susliksImg.setX(activity.mPositions[i][0]);
                    activity.susliksImg.setY(activity.mPositions[i][1]);
                    activity.susliksImg.setVisibility(View.VISIBLE);
                    //随机的时间传入为地鼠出现的延迟时间 (0 + 500) =< randomTime < (500 + 500)
                    int randomTime = new Random().nextInt(DELAY_TIME) + DELAY_TIME;
                    activity.next(randomTime);
                }
            }


    }
    //清除数据
    private void clear() {
        totalCount = 0;
        beginBtn.setText(R.string.begin_game);
        beginBtn.setEnabled(true);
        hitCount = 0;
        susliksImg.setVisibility(View.GONE);
    }
}

通过handleMessage方法再次调用弱引用的MainAcitiviity的next方法send message就可以将地鼠出现及相应操作循环起来。同时静态类和弱引用也防止了内存的泄漏。

运行的结果如下图：