我创建了一个自定义compound control，用于在列表视图中显示计时器。在其中，我使用处理程序每1秒更新显示的计时器值。问题是这个处理程序一直在执行，即使列表项滚动到视图之外，或者即使我退出应用程序。如何阻止此处理程序执行？
我尝试了handler.removeCallbacks()，但它似乎无效。
public class TimerLayout extends LinearLayout {
private static final String LOG_TAG = "TimerLayout";
Date startTime;
TextView tv_timer;
Button btn_cancelTimer;
Runnable updateTimerThread;
Handler handler;
public TimerLayout(Context context, AttributeSet attrs) {
super(context,attrs);
setOrientation(LinearLayout.VERTICAL);
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
inflater.inflate(R.layout.timer, this, true);
tv_timer = (TextView) getChildAt(0);
btn_cancelTimer = (Button) ((ViewGroup) getChildAt(1)).getChildAt(1);
handler = new Handler();
updateTimerThread = new Runnable(){
@Override
public void run() {
//calculate total time
long timeInMilliSeconds = (new Date().getTime()) - startTime.getTime();
int secs = (int) (timeInMilliSeconds / 1000) % 60 ;
int mins = (int) ((timeInMilliSeconds / (1000*60)) % 60);
int hours = (int) ((timeInMilliSeconds / (1000*60*60)) % 24);
tv_timer.setText(String.format("%02d", hours)
+ ":" + String.format("%02d", mins)
+ ":" + String.format("%02d", secs)
);
handler.postDelayed(this, 1000);
}
};
}
public void start(Date startTime) {
if (startTime != null) {
this.startTime = startTime;
handler.postDelayed(updateTimerThread, 0);
}
}
btn_cancelTimer.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View view){
handler.removeCallbacks(updateTimerThread);
}
});
}