android开发者 - 计时器应用

Question

我写了一个计时器代码。清除功能不清除时间值（当我按下清除仅文本更改，但时间值继续形成停止点）这里是代码，任何激活清除按钮的建议？：

public class MainActivity extends Activity {

    private Button startButton;     
    private Button stopButton;  
    private Button clearButton;
    private TextView timeValue;     
    private long timeStart = 0L;
    private Handler timeHandler = new Handler();
    long timeInMilisec = 0L;
    long timeMemo = 0L;
    long timeUpdate = 0L;

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

        timeValue = (TextView) findViewById(R.id.timeValue);        
        startButton = (Button) findViewById(R.id.startButton);      
        startButton.setOnClickListener(new View.OnClickListener() { 

            public void onClick(View view) {

                timeStart = SystemClock.uptimeMillis();     
                timeHandler.postDelayed(updateTimerThread, 0); 

            }

        });

        stopButton = (Button) findViewById(R.id.stopButton);        
        stopButton.setOnClickListener(new View.OnClickListener() {       

            public void onClick(View view) {        
                timeMemo += timeInMilisec;      
                timeHandler.removeCallbacks(updateTimerThread); 

            }

        });
     clearButton = (Button) findViewById(R.id.clearButton);
     clearButton.setOnClickListener(new View.OnClickListener() {                
        public void onClick(View v) {
            switch (v.getId()) {
            case R.id.clearButton:

                timeValue.setText("00:00:00");
                int secs = 0;       
                int mins = 0;       
                secs = 0;   
                int milliseconds = 0;
                timeInMilisec = SystemClock.uptimeMillis() - timeStart;     
                timeUpdate = timeMemo + timeInMilisec;      
                timeValue.setText("" + mins + ":"       
                        + String.format("%02d", secs) + ":"     
                        + String.format("%03d", milliseconds)); 

                timeHandler.removeCallbacksAndMessages(updateTimerThread);
                timeValue.setText("00:00:00");

                break;                  
            }                   
        }
    });

    }

    private Runnable updateTimerThread = new Runnable() {       

        public void run() {

            timeInMilisec = SystemClock.uptimeMillis() - timeStart;     
            timeUpdate = timeMemo + timeInMilisec;      
            int secs = (int) (timeUpdate / 1000);       
            int mins = secs / 60;       
            secs = secs % 60;       
            int milliseconds = (int) (timeUpdate % 1000);       
            timeValue.setText("" + mins + ":"       
                    + String.format("%02d", secs) + ":"     
                    + String.format("%03d", milliseconds));     
            timeHandler.postDelayed(this, 0);

        }

    };      


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

Answer 1

在ClearButton onClick中，您没有重置“timerstart”和“timeMemo”变量的值。这就是为什么只更新文本但没有重置计时器的原因。

Answer 2

您应该重置 timeMemo 变量。

clearButton.setOnClickListener(new View.OnClickListener() {                
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.clearButton:

            // Clear the timestart and timeMemo
            timeMemo = 0L;

            timeValue.setText("00:00:00");
            int secs = 0;       
            int mins = 0;       
            secs = 0;   
            int milliseconds = 0;
            timeInMilisec = SystemClock.uptimeMillis() - timeStart;     
            timeUpdate = timeMemo + timeInMilisec;      
            timeValue.setText("" + mins + ":"       
                    + String.format("%02d", secs) + ":"     
                    + String.format("%03d", milliseconds)); 

            timeHandler.removeCallbacksAndMessages(updateTimerThread);
            timeValue.setText("00:00:00");
            timeHandler.removeCallbacks(updateTimerThread);

            break;         
        }                   
    }
});