Android HandlerThread的用法

HandlerThread 继承自Thread,内部封装了Looper。

首先Handler和HandlerThread的主要区别是：Handler与Activity在同一个线程中，HandlerThread与Activity不在同一个线程，而是别外新的线程中(Handler中不能做耗时的操作)。

用法：

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Handler.Callback;
import android.os.HandlerThread;
import android.os.Message;  

public class MainActivity extends Activity {
    HandlerThread handlerThread = new HandlerThread("test");
    Handler handler;  

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        System.out.println("cur_id="+Thread.currentThread().getId());  

        handlerThread.start();
        System.out.println("handlerThread.id=" + handlerThread.getId());
        //post(runnable)，只是直接运行了run()，run()内ThreadId与UIThread是一样的
//      handler = new Handler();
        //post(runnable)，将runnable运行在handlerThread中，这是非UIThread的
        handler = new Handler(handlerThread.getLooper(), new Callback() {  

            @Override
            public boolean handleMessage(Message msg) {
                System.out.println("receive message.whatA=" + msg.what);
                if (msg.what == ) {
                    return true;//不再向外层传递
                } else {
                    return false; //外层的handleMessage() 继续执行
                }  

            }
        }) {
            @Override
            public void handleMessage(Message msg) {
                // TODO Auto-generated method stub
                super.handleMessage(msg);
                System.out.println("receive message.whatB=" + msg.what);
            }
        };
        handler.post(new Runnable() {  

            @Override
            public void run() {
                System.out.println("handler_post_cur_id="+Thread.currentThread().getId());
                handler.sendEmptyMessage();
                handler.sendEmptyMessage();
            }
        });  

    }  

}  

运行结果：

- ::31.590: I/System.out(): cur_id=
- ::31.590: I/System.out(): handlerThread.id=
- ::31.590: I/System.out(): handler_post_cur_id=
- ::31.600: I/System.out(): receive message.whatA=
- ::31.600: I/System.out(): receive message.whatA=
- ::31.600: I/System.out(): receive message.whatB=