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 == 1) {  
                    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(1);  
                handler.sendEmptyMessage(2);  
            }  
        });  
          
    }  
  
}  

运行结果：

01-23 07:12:31.590: I/System.out(12386): cur_id=1  
01-23 07:12:31.590: I/System.out(12386): handlerThread.id=1866  
01-23 07:12:31.590: I/System.out(12386): handler_post_cur_id=1866  
01-23 07:12:31.600: I/System.out(12386): receive message.whatA=1  
01-23 07:12:31.600: I/System.out(12386): receive message.whatA=2  
01-23 07:12:31.600: I/System.out(12386): receive message.whatB=2