当我打开另一个活动时如何停止铃声？

1. 这是正常的文字

2. 这是一个列表项

   时间选择器 按钮开始报警、停止报警；TextView 开始时间、当前时间、问题；编辑文本答案；

   定时器定时器；MyTimerTask myTimerTask;

   内部探求；

   private String Questionairs[] = {“PHP 是什么？”，“HTML 是什么？”，“CSS 是什么？”}; private String QAnswer[] = {"个人主页"、"超文本标记语言"、"级联样式表"};

   int randomizer = (int) (Math.random() * 2);

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

    timePicker = (TimePicker) findViewById(R.id.timePicker);
    timePicker.setIs24HourView(true);
    StartAlarm = (Button) findViewById(R.id.StartAlarm);
    StopAlarm = (Button) findViewById(R.id.StopAlarm);
    StartTime = (TextView) findViewById(R.id.StartTime);
    CurrentTime = (TextView) findViewById(R.id.CurrentTime);
    Questions = (TextView) findViewById(R.id.Questions);
    Answers = (EditText) findViewById(R.id.Answers);
   
    timer = new Timer();
    myTimerTask = new MyTimerTask();
   
   
    final Ringtone r = RingtoneManager.getRingtone(getApplicationContext(), RingtoneManager.getDefaultUri(RingtoneManager.TYPE_RINGTONE));
   
   
   
   
    StartAlarm.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
   
            int sTimeH = timePicker.getHour();
            int sTimeM = timePicker.getMinute();
   
            if(sTimeH < 10  &&  sTimeM < 10)
            {
                String holderH = String.valueOf(sTimeH);
                String holderM = String.valueOf(sTimeM);
   
                String AlarmTime = "0" + holderH + ":0" + holderM;
                StartTime.setText(AlarmTime);
            }
            else if(sTimeH > 10  &&  sTimeM < 10)
            {
                String holderH = String.valueOf(sTimeH);
                String holderM = String.valueOf(sTimeM);
   
                String AlarmTime = holderH + ":0" + holderM;
                StartTime.setText(AlarmTime);
            }
            else if(sTimeH < 10  &&  sTimeM > 10)
            {
                String holderH = String.valueOf(sTimeH);
                String holderM = String.valueOf(sTimeM);
   
                String AlarmTime = "0" + holderH + ":" + holderM;
                StartTime.setText(AlarmTime);
            }
   
            else{
                String holderH = String.valueOf(sTimeH);
                String holderM = String.valueOf(sTimeM);
   
                String AlarmTime = holderH + ":" + holderM;
                StartTime.setText(AlarmTime);
            }
   
            if(timer != null){
                timer.cancel();
            }
   
            timer = new Timer();
            myTimerTask = new MyTimerTask();
   
            timer.schedule(myTimerTask, 1000, 1000);
   
            Timer t = new Timer();
            t.scheduleAtFixedRate(new TimerTask() {
                @Override
                public void run() {
   
                    if (CurrentTime.getText().toString().equals(StartTime.getText().toString())){
                        r.play();
                    }
                }
            }, 0, 1000);
   
    }
   

   });

    StopAlarm.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
   
            Questions.setText(Questionairs[0]);
            Answers.setEnabled(true);
   
   
   
            if(Answers.getText().toString().equals(QAnswer[0]) && Questions.getText().toString().equals((Questionairs[0])))
            {
                Intent i = new Intent(getApplicationContext(),HomePage.class);
                startActivity(i);
                i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
                finish();
            }
   
        }
    });
   

} 类 MyTimerTask 扩展了 TimerTask {

    @Override
    public void run() {
        Calendar calendar = Calendar.getInstance();
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("HH:mm");
        final String strDate = simpleDateFormat.format(calendar.getTime());

        runOnUiThread(new Runnable(){

            @Override
            public void run() {
                CurrentTime.setText(strDate);
            }});
    }

}

}