Java 如果超过5秒，则启动动画

如何检查Java（Android）中是否已过5秒

---

为此，可以使用

System.nanoTime（）

来测量经过的时间

例如，您可以执行以下操作：

long start = System.nanoTime();
while (System.nanoTime() - start < 5000000);
StartAnimation();

另外，如果线程正在做一些其他事情，您可以这样做（但这不是5秒）

当然，您可以启动自己的线程来启动动画（在我看来，这可能是最好的解决方案）：

编辑：

在阅读您最后的评论后： 我将把这个逻辑传递给startAnimation：

try {
    Thread.sleep(5000);
    startAnimation();
} catch (InterruptedException e) {
     // handle Interruption Exception here
}

// Class variable:
long lastAnimationStart = 0;

void StartAnimation() {
    if (lastAnimationStart = 0 || System.nanoTime() - lastAnimationStart >= 5000000) {
        lastAnimationStart = System.nanoTime();
        // Animation stuff here
    }
}

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您应该使用处理程序并向其发送延迟消息。大概是这样的：

private static final int MSG_START_ANIMATION = 1337;
private Handler mAnimationHandler = new Handler() {

    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
            case MSG_START_ANIMATION:
                startAnimation();
                break;
        }
    }
};
private final ViewPager.OnPageChangeListener mOnPageChangeListener = new ViewPager.OnPageChangeListener() {
    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {
        mAnimationHandler.removeMessages(MSG_START_ANIMATION);
        mAnimationHandler.sendEmptyMessageDelayed(MSG_START_ANIMATION, TimeUnit.SECONDS.toMillis(5));
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
};

另外，请阅读这篇关于通过内部处理程序类泄漏上下文的博文：

new Thread(new Runnable() {
    public void run() {
        try {
            Thread.sleep(5000);
            // Make sure animation will run on UI Thread!
            runOnUiThread(new Runnable() {
                @Override
                public void run() {
                    StartAnimation();
                }
            });
        } catch (InterruptedException e) {
            // Handle exception
        }

    }
}).start();

// Class variable:
long lastAnimationStart = 0;

void StartAnimation() {
    if (lastAnimationStart = 0 || System.nanoTime() - lastAnimationStart >= 5000000) {
        lastAnimationStart = System.nanoTime();
        // Animation stuff here
    }
}

private static final int MSG_START_ANIMATION = 1337;
private Handler mAnimationHandler = new Handler() {

    @Override
    public void handleMessage(Message msg) {
        switch (msg.what) {
            case MSG_START_ANIMATION:
                startAnimation();
                break;
        }
    }
};
private final ViewPager.OnPageChangeListener mOnPageChangeListener = new ViewPager.OnPageChangeListener() {
    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

    }

    @Override
    public void onPageSelected(int position) {
        mAnimationHandler.removeMessages(MSG_START_ANIMATION);
        mAnimationHandler.sendEmptyMessageDelayed(MSG_START_ANIMATION, TimeUnit.SECONDS.toMillis(5));
    }

    @Override
    public void onPageScrollStateChanged(int state) {

    }
};