Question

我需要一个计时器来启动任何时候我按下一个按钮（按钮本身），显示自实时按下它已经过了几秒钟。无论何时再次按下，定时器将重置为0并再次开始递增

我知道这不是方法，按钮工作正常，但计时器应该在onCreate？我不确定这应该如何使用按钮

/usr/local/sbin

Answer 1

试试这个：使用处理程序

 long startTime = 0;
 long elapsedTime ;

//runs without a timer by reposting this handler at the end of the runnable
Handler timerHandler = new Handler();
Runnable timerRunnable = new Runnable() {

    @Override
    public void run() {
        long millis = System.currentTimeMillis() - startTime;
        int seconds = (int) (millis / 1000);
        int minutes = seconds / 60;
        int hours = minutes / 60;
        seconds = seconds % 60;
        //textview for displaying time..
        timerTextView.setText(String.format("%d:%02d:%02d", hours, minutes, seconds));

        timerHandler.postDelayed(this, 1000);
    }
};

 b.setOnClickListener(new View.OnClickListener() { //b is your button

    @Override
    public void onClick(View v) {
        Button b = (Button) v;
        if (b.getText().equals("Stop")) {
            elapsedTime = System.currentTimeMillis() - startTime;
            timerHandler.removeCallbacks(timerRunnable);
            b.setText("Resume");
        } else {
            startTime = System.currentTimeMillis() - elapsedTime;
            timerHandler.postDelayed(timerRunnable, 0);
             Calendar cs = Calendar.getInstance();
            System.out.println("Current time => " + cs.getTime());
            SimpleDateFormat df = new SimpleDateFormat("HH:mm");
            String formattedDate = df.format(cs.getTime());
            timerTextView.setText(formattedDate);
            b.setText("Stop");
        }
    }
});

它将计算经过时间并显示停止后的时间...

Answer 2

另一种简单的方法是使用Handler

mHandler = new Handler();

点击按钮即可调用updateSec();方法，以1秒的间隔更新秒

Runnable UpdateRunnable = new Runnable() {

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

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

示例

button.setOnClickListener(new OnClickListener() {

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

Answer 3

您可以使用线程：

@Override
public void onClick(View view){
switch(view.getId()){
case R.id.button:
new Thread(new Runnable() {
@Override
public void run() {
try{
Thread.sleep(1000);
} catch(InterruptedException e) {
e.printStackTrace();
}
count++;
textView.post(new Runnable() {
@Override
public void run() {
textView.setText(count + "");
}
});
}
}
}).start;
break;
}
}

视图必须在主线程上更新，因此您需要使用具有runnable instance作为参数的post（）方法。

或者，您也可以使用AsyncTask。

按下按钮后每秒运行一个方法

3 个答案: