Question

实际上，我设计了一个单独的Timer类，带有处理程序，用于在textview上显示分钟和秒。这工作正常，因为我已经调试它和处理程序将reaise句柄但文本视图没有得到更新pl帮助我在这方面。我正在为Timer Class标记下面的代码。提前谢谢。

public class Timer
{
    private int _interval;
    public int getInterval()
    {
        return _interval;
    }
    public void setInterval(int delay)
    {
        _interval = delay;
    }
    private Handler handler;
    private Runnable _tickHandler;
    private Runnable delegate;
    private boolean ticking;
    public boolean getIsTicking()
    {
        return ticking;
    }
    public Timer(int interval)
    {
        _interval = interval;
        handler = new Handler();
    }
    public Timer(int interval, Runnable onTickHandler)
    {
        _interval = interval;
        setOnTickHandler(onTickHandler);
        handler = new Handler();
    }
    public void start(int interval, Runnable onTickHandler)
    {
        if (ticking) return;
        _interval = interval;
        setOnTickHandler(onTickHandler);
        handler.postDelayed(delegate, _interval);
        ticking = true;
    }
    public void start()
    {
        if (ticking) return;
        handler.postDelayed(delegate, _interval);
        ticking = true;
    }
    public void stop()
    {
        handler.removeCallbacks(delegate);
        ticking = false;
    }
    public void setOnTickHandler(Runnable onTickHandler)
    {
        if (onTickHandler == null)        return;
        _tickHandler = onTickHandler;
        delegate = new Runnable()
        {
            public void run()
            {
                if (_tickHandler == null) return;
                _tickHandler.run();
                handler.postDelayed(delegate, _interval);
            }
        }
        ;
    }
}

及以下是我用于更新文本视图的代码

Timer tmr = new Timer(100,new Runnable()
{
    public void run()
    {
        long millis = System.currentTimeMillis() - mStartTime;
        int seconds = (int) (millis / 1000);
        int minutes = seconds / 60;
        seconds    = seconds % 60;
        lblDevOnOff.setText("");
        lblDevOnOff.setText(String.format("%d:%02d", minutes,seconds));
    }
}
);
tmr.start();

Answer 1

将此代码放入

handler或runOnUIThread()类似这样的内容

runOnUIThread(new Runnable(){

public void run(){

lblDevOnOff.setText("");
lblDevOnOff.setText(String.format("%d:%02d", minutes,seconds));
}
})

你应该这样做，因为任何与UI相关的东西都应该只在UI Thread上运行......

Answer 2

是的，这是来自Android Dev Guide：

因此，Android的单线程模型只有两个规则：


不要阻止UI线程

不要从UI线程外部访问Android UI工具包

文本视图不会通过处理程序获得更新

2 个答案: