Question

public class MainActivity extends Activity {
private CountDownTimer countDownTimer;
private CountDownTimer countDownTimer2;//second timer count down

private boolean timerStart = false;//timer start
private boolean timerStart2 = false;

private Button startButton;//timer button
private Button startButton2;

public TextView text;
public TextView text2;//text field for second timer

public TextView text3;// text 3 and 4 meant to hold the elapsed time for each timer
public TextView text4;

private final long startTime = 90 * 1000;//first timer
private final long interval = 1 * 1000;

private final long startTime2 = 30 * 1000; //second timer time
private final long interval2 = 1 * 1000;

TextToSpeech tts;

private class countDownTimerListener implements OnClickListener {

    @Override
    public void onClick(View v) {
        if (!timerStart){
            countDownTimer.start();
            timerStart = true;
            startButton.setText("Stop");
            startButton2.setEnabled(false);
        } else {
            countDownTimer.cancel();
            timerStart = false;
            startButton.setText("Restart");             
        }                   
    }       
}
private class countDownTimerListener2 implements OnClickListener {

    @Override
    public void onClick(View v) {
        if (!timerStart2){
            countDownTimer2.start();
            timerStart2 = true;
            startButton2.setText("Stop");
            startButton.setEnabled(false);
        } else {
            countDownTimer2.cancel();
            timerStart2 = false;
            startButton2.setText("Restart");
        }                   
    }       
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    startButton = (Button)this.findViewById(R.id.button1);
    startButton2 = (Button)this.findViewById(R.id.button2);

    startButton.setOnClickListener(new countDownTimerListener());
    startButton2.setOnClickListener(new countDownTimerListener2());

    text = (TextView) this.findViewById(R.id.textView1);
    text2 = (TextView) this.findViewById(R.id.textView4);//second timer text

    text3 = (TextView) this.findViewById(R.id.textView5);//text field for elapsed time
    text4 = (TextView) this.findViewById(R.id.textView7);
    //this is where I take the text view from xml and assign to text 3 and 4.
    countDownTimer = new MyTimer(startTime, interval, "You have completed your 90 second Timer", text, text3);//first timer
    text.setText(text.getText() + String.valueOf(startTime/1000));

    countDownTimer2 = new MyTimer(startTime2, interval2, "You have completed your 30 second Timer", text2, text4);//second timer start
    text2.setText(text2.getText() + String.valueOf(startTime2/1000));//second timer text field

    tts = new TextToSpeech(getApplicationContext(), new TextToSpeech.OnInitListener() {

        @Override
        public void onInit(int status) {
            if(status != TextToSpeech.ERROR){
                tts.setLanguage(Locale.US);
            }
        }                           
    });
}

public class MyTimer extends CountDownTimer { 
    private String ttsString;
    private TextView textview;
    private TextView timeElapsedView;
    private long timeElapsed;
    private long startTime;

    public MyTimer(long startTime, long interval, String ttsString, TextView textview, TextView timeElapsedView){
        super(startTime, interval);
        this.ttsString = ttsString;
        this.textview = textview;
        this.timeElapsedView = timeElapsedView;
    }

    @Override
    public void onTick(long millisUntilFinished) {
        textview.setText("" + (millisUntilFinished / 1000));
        //startTime - millisUntilFinished elapsed time
        timeElapsed = ((startTime - millisUntilFinished) / 1000);
        timeElapsedView.setText("" + String.valueOf(timeElapsed));
    }

    @Override
    public void onFinish() {
        textview.setText("Time's up!"); 
        //Vibrator vibrator = (Vibrator)this.getSystemService(VIBRATOR_SERVICE);
        //vibrator.vibrate(600);
        ToneGenerator toneG = new ToneGenerator(AudioManager.STREAM_ALARM, 100);
        toneG.startTone(ToneGenerator.TONE_CDMA_ALERT_CALL_GUARD, 200);
        tts.speak(ttsString, TextToSpeech.QUEUE_ADD, null);     
    }
}

}

我正在尝试用Java为Android创建一个倒数计时器。我希望它显示从1开始的经过时间，以及倒计时的剩余时间。我可以让倒数时间工作正常但是当我经过时间时，它从89971开始并从那里开始计数。关于如何解决这个问题的任何建议？这是我用来显示计时器的代码。

Answer 1

startTime方法中的onTick()来自哪里？如果它是您MyTimer级的实例变量，则您忘记提及它。此外，它是一个很长的，以毫秒为单位的时间值，就像millisInFuture - 值一样。这意味着，你应该做这样的事情：

timeElapsed = (startTime - millisUntilFinished) / 1000;

您可以将timeElapsed作为onTick() - 方法的局部变量。

披露完整代码后更新：

请在startTime - 类中添加MyTimer实例变量，您可以在MyTimer - 构造函数中正确初始化，因为您在两个不同的开始时间使用MyTimer，但在onTick()中，您使用外部类中的startTime实例变量，该变量仅对第一个实例（countDownTimer）有效。

建议我在android中修复我的倒数计时器

1 个答案: