Question

Android中为什么可以new Runnable

Answer 1

类似Thread类，重载run方法。
Runnable mRunnable = new Runnable() {

public void run() {

//自定义功能
}

};

然后一般通过Handler，发送到消息队列里面去运行，
如 Handler mHandler = new Handler();
mHandler.post(mRunnable);
mHandler.postDelayed (mRunnable);
一些原型如下：

public final boolean post(Runnable r)
{
return sendMessageDelayed(getPostMessage(r), 0);
}

public final boolean postDelayed(Runnable r, long delayMillis)
{
return sendMessageDelayed(getPostMessage(r), delayMillis);
}

public final boolean postAtTime(Runnable r, Object token, long uptimeMillis)
{
return sendMessageAtTime(getPostMessage(r, token), uptimeMillis);
}