Question

public class MainActivity extends AppCompatActivity {

  @Bind(R.id.timerText)
  TextView timerText;
  @Bind(R.id.pauseButton)
  ImageButton pauseButton;
  @Bind(R.id.restartButton)
  ImageButton restartButton;
  @Bind(R.id.startButton)
  ImageButton startButton;

  private CountDownTimer mCounter;

  long millisecondsLeft;

  boolean isFirstLaunch = true;
  boolean isPaused = false;
  boolean isRunning = false;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    ButterKnife.bind(this);

    startButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (isFirstLaunch) {
                pauseButton.setVisibility(View.VISIBLE);
                restartButton.setVisibility(View.VISIBLE);
                startButton.setVisibility(View.GONE);
                isFirstLaunch = false;
                setTheTimer(60 * 25 * 1000);
            } else {
                isRunning = true;
                isPaused = false;
                changeVisibility();
                setTheTimer(millisecondsLeft);
            }
        }
    });

    pauseButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            mCounter.cancel();
            mCounter = null;

            isRunning = false;
            isPaused = true;
            changeVisibility();
        }
    });

    restartButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            restart();
        }
    });
  }

  public void changeVisibility () {

    if (isPaused) {
        startButton.setVisibility(View.VISIBLE);
        pauseButton.setVisibility(View.GONE);
    }
    if (isRunning) {
        pauseButton.setVisibility(View.VISIBLE);
        startButton.setVisibility(View.GONE);
    }
  }

  public void restart () {
    if (mCounter != null) {
        mCounter.cancel();
        mCounter = null;
        isRunning = true;
        isPaused = false;
        changeVisibility();
        setTheTimer(60 * 25 * 1000);
    } else {
        isRunning = true;
        isPaused = false;
        changeVisibility();
        setTheTimer(60 * 25 * 1000);
    }
  }


  private void setTheTimer(long value) {

    if (mCounter == null) {

        mCounter = new CountDownTimer(value, 1000) {

            @Override
            public void onTick(long millisUntilFinished) {

                long minutes = (millisUntilFinished / 1000) / 60;
                int seconds = (int) ((millisUntilFinished / 1000) % 60);
                millisecondsLeft = millisUntilFinished;


                timerText.setText(minutes + ":" + seconds);
            }

            @Override
            public void onFinish() {
                timerText.setText("Done!");
            }
        };
        mCounter.start();
      }
    }
}

我遇到的问题是我提供的代码的底部。我在论坛中找到的一些代码，它有一个我无法解决的问题。我的计时器始终从25:0开始，然后进入24:59。这也会在显示器中稍后出现，例如：23:0。我试图使秒始终显示两位数而不是一个0。

Answer 1

这可以通过DecimalFormat完成：

// modified from your above to highlight what you need to do
NumberFormat f = new DecimalFormat("00");
int seconds = (int) ((millisUntilFinished / 1000) % 60);
timerText.setText(minutes + ":" + f.format(seconds)); // formatter used here

或作为替代用途String.format()：

// modified from your above to highlight what you need to do
String format = "%02d"; // two digits
timerText.setText(minutes + ":" + String.format(format, time)); // formatter used here

Answer 2

使用String.format()对您的seconds进行零填充，以确保它始终为两位数：

timerText.setText(minutes + ":" + String.format("%02d", seconds));

Answer 3

NumberFormat formatter = new DecimalFormat("#0.00");     

System.out.println(formatter.format(2.0));

输出将为2.00

这对您来说更容易嵌入。

倒计时器显示25：0而不是25:00

3 个答案: