java - 从按下按钮开始每秒运行一个方法

Question

我需要一个计时器在我按下按钮(在按钮本身上)时启动，实时显示自按下按钮以来经过了多少秒。每当再次按下时，计时器将重置为 0 并再次开始递增

我知道这不是实现它的方法，按钮工作正常但计时器应该在 onCreate 中？我不确定这应该如何与按钮一起使用

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        downloadedImg = (ImageView) findViewById(R.id.imageView);
    }

    public void clickAsync(View view) {

            new ImageDownloader().execute(downloadUrl);
            int seconds = 0;
            Button button = (Button) view;

            button.setText("Seconds since clicked: " + seconds);
            Timer timer = new Timer();

            //each time button is clicked, time is reset to 0 and increments in real time
            timer.scheduleAtFixedRate(new TimerTask()
            {
                public void run()
                {
                    seconds = 0;
                    seconds++;
                    button.setText("Seconds since clicked: " + seconds);
                }
            }, 0, 1000);
      }
}

Answer 1

另一种简单的方法是使用 Handler

mHandler = new Handler();

只需调用 updateSec();方法，点击一个按钮，它就会以一秒为间隔更新 sec

Runnable UpdateRunnable = new Runnable() {

    @Override
    public void run() {
        updateSec();
    }
};

    public void updateSec() {
          mSeconds++;
          mHandler.postDelayed(UpdateRunnable, 1000);
     }

例子

button.setOnClickListener(new OnClickListener() {

public void onClick(View v) {
    mSeconds = 0;
    updateSec();//it'll update sec variable every second.
  }
});