用于打印当前MessageQueue中的所有Message

Helper.java

// usage: Choreographer.getInstance().postFrameCallback(new Helper());
public class Helper implements Choreographer.FrameCallback {

    private static final String TAG = "IndexHelper";

    private Field messagesField;
    private Field nextField;

    public Helper() {
        try {
            messagesField = MessageQueue.class.getDeclaredField("mMessages");
            messagesField.setAccessible(true);
            nextField = Message.class.getDeclaredField("next");
            nextField.setAccessible(true);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        }
    }

    private void printMessages() {
        MessageQueue queue = Looper.myQueue();
        try {
            Message msg = (Message) messagesField.get(queue);
            StringBuilder sb = new StringBuilder();
            while (msg != null) {
                sb.append(msg.toString());
                sb.append("\n");
                msg = (Message) nextField.get(msg);
            }
            Log.i(TAG, sb.toString());
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void doFrame(long frameTimeNanos) {
        Choreographer.getInstance().postFrameCallback(this);

        printMessages();
    }
}