android - Handler dispatchMessage

Question

额，有个疑问，求大神赐教。
MyHandler继承自Handler:

    class MyHandler extends Handler {
        @Override
        public void dispatchMessage(Message msg) {
            super.dispatchMessage(msg);
            Log.e(TAG, "disaptch message");
        }

        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            Log.e(TAG, "handle message");
        }
    }

然后写了一个Message，设置了它的callback，然后把这个message发送出去。

        mMyHandler = new MyHandler();
        Message msg = Message.obtain(mMyHandler, new Runnable() {
            @Override
            public void run() {
                Log.e(TAG, "Message Callback");
            }
        });
        mMyHandler.sendMessage(msg);

问题是，既然MyHandler的dispatchMessage方法被我复写了，那么在Looper调用MyHandler.dispatchMessge
方法时，应该不会去调Message的callback，那么Log.e(TAG, "Message Callback");应该就不会执行，但为什么还是会打印出来？

Answer 1

Is the super.dispatchMessage(msg); method not executed? You overridden it, but the original method is still executed. Why is it not executed?

Answer 2

super.dispatchMessage(msg) source code is to first determine if there is an incorrect callback interface, and if so, execute the callback.