如何重复mHandler.postDelayed()？

Question

有没有更好的方法来做这件事？这是我正在制作的一个Kegel应用程序，没有人想在他们变老的时候滴水，对吧？！我尝试过在for循环中使用它，但它只循环一次。:(现在我只是输入更多，因为网站不允许我发布，因为它说我的帖子看起来主要是代码。

public final void onClick(View view) {
    switch (view.getId()) {
        case R.id.tvBeginner:
            tvBeginner.setText("Beginner exercise in progress...");

            Runnable clenchRunnable = new Runnable() {
                @Override
                public void run() {
                    try {
                        tvExpert.setText("");
                        tvIntermediate.setText("Clench!!!");
                        tvIntermediate.setTextSize(60);
                        vibrate.vibrate(250);
                        clenchDone = true;
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            };

            Runnable relaxRunnable = new Runnable() {
                @Override
                public void run() {
                    try {
                        tvIntermediate.setText("");
                        tvExpert.setText("Relax...");
                        tvExpert.setTextSize(40);
                        tvExpert.setTextColor(Color.GREEN);
                        vibrate.vibrate(250);
                        clenchDone = false;
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            };

            clenchHandler.postDelayed(clenchRunnable, 1000);
            relaxHandler.postDelayed(relaxRunnable, 2000);
            clenchHandler.postDelayed(clenchRunnable, 3000);
            relaxHandler.postDelayed(relaxRunnable, 4000);
            clenchHandler.postDelayed(clenchRunnable, 5000);
            relaxHandler.postDelayed(relaxRunnable, 6000);
            clenchHandler.postDelayed(clenchRunnable, 7000);
            relaxHandler.postDelayed(relaxRunnable, 8000);
            clenchHandler.postDelayed(clenchRunnable, 9000);
            relaxHandler.postDelayed(relaxRunnable, 10000);
            clenchHandler.postDelayed(clenchRunnable, 11000);
            relaxHandler.postDelayed(relaxRunnable, 12000);
            clenchHandler.postDelayed(clenchRunnable, 13000);
            relaxHandler.postDelayed(relaxRunnable, 14000);
            clenchHandler.postDelayed(clenchRunnable, 15000);
            relaxHandler.postDelayed(relaxRunnable, 16000);
            clenchHandler.postDelayed(clenchRunnable, 17000);
            relaxHandler.postDelayed(relaxRunnable, 18000);
            clenchHandler.postDelayed(clenchRunnable, 19000);
            relaxHandler.postDelayed(relaxRunnable, 20000);


            break;

Answer 1

你可以在它们各自的runnables中调用relaxHandler，clenchHandler，并保留一个计数器来记录你想要调用它的次数，例如：

int i =0;
Runnable relaxRunnable = new Runnable() {
            @Override
            public void run() {
                try {
                    tvIntermediate.setText("");
                    tvExpert.setText("Relax...");
                    tvExpert.setTextSize(40);
                    tvExpert.setTextColor(Color.GREEN);
                    vibrate.vibrate(250);
                    clenchDone = false;
                } catch (Exception e) {
                    e.printStackTrace();
                }
                if(i <= numTimesToRun) {
                 relaxHandler.postDelayed(relaxRunnable, time_out_variable);
                 i++;
                }
            }
        };

然后对clenchHandler执行相同的操作，使其运行x次

Answer 2

所以我要试一试...

private static final int SWITCH_DELAY = 1000;

private Handler handler;
private boolean beginnerCycleActive = false;
private boolean clenched = false;

public final void onClick(View view) {
    switch (view.getId()) {
        case R.id.tvBeginner:
            startBeginnerCycle();
            break;
    }
}

private void startBeginnerCycle(){
    beginnerCycleActive = true;
    tvBeginner.setText("Beginner exercise in progress...");

    doCycle();
}

private void stopBeginnerCycle(){
    beginnerCycleActive = false;
}

private void doCycle(){
    onClench();

    handler.postDelayed(new Runnable(){
        public void run(){
            onRelax();

            handler.postDelayed(new Runnable(){
                public void run(){
                    if(beginnerCycleActive) doCycle();
                }
            }, SWITCH_DELAY);
        }
    }, SWITCH_DELAY);
}

private void onClench(){
    try {
        tvExpert.setText("");
        tvIntermediate.setText("Clench!!!");
        tvIntermediate.setTextSize(60);
        vibrate.vibrate(250);
        clenched = true;
    } 
    catch (Exception e) {
        e.printStackTrace();
    }
}

private void onRelax(){
    try {
        tvIntermediate.setText("");
        tvExpert.setText("Relax...");
        tvExpert.setTextSize(40);
        tvExpert.setTextColor(Color.GREEN);
        vibrate.vibrate(250);
        clenched = false;
    } 
    catch (Exception e) {
        e.printStackTrace();
    }
}

看起来干净多了，不需要重复，可以通过调用stopBeginnerCycle()轻松地停止

Answer 3

你应该看看ScheduledThreadPoolExecutor。它可用于以循环周期在固定时间运行Runnable。下面的例子将向你展示它是如何工作的。

class YourRunnable implements Runnable {
    @Override
    public void run() {
        //Do your stuff
    } 
}

ScheduledThreadPoolExecutor exec = new ScheduledThreadPoolExecutor(1);
long period = 10000; // the period between successive executions
exec.scheduleAtFixedRate(new YourRunnable (), 0, duration, TimeUnit.MICROSECONDS); // It can be seconds, miliseconds...

我认为在您的案例中使用ScheduledThreadPoolExecutor非常容易。