Handler主線程子線程之間的互相通信

 

Handler主線程子線程之間的互相通信

 

package com.wyl.dansnote;


import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class SecActivity extends Activity implements OnClickListener{
    Button btn_main_to_work;
    Button btn_work_to_main;
    Handler handler;
    Handler handler_main_to_work;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.sec_main);
        initViews();
        initMainHandler();//子線程向主線程發送消息
        new MainToWorkThread().start();//主線程向子線程發送消息
        initClicks();
    }
    

    private void initMainHandler() {
        handler = new MainHandler();
    }
    class MainHandler extends Handler{
        @Override
        public void handleMessage(Message msg) {
            String msg_rtn = (String)msg.obj;
//            System.out.print("MainHandler.handleMessage():"+msg_rtn+",當前線程："+Thread.currentThread().getName());
            Toast.makeText(SecActivity.this, "MainHandler.handleMessage():"+msg_rtn+",當前線程："+Thread.currentThread().getName(), 100).show();
        }
    }
    //子線程向主線程發送消息
    class WorktoMainThread extends Thread{
        @Override
        public void run() {
            Message msg = handler.obtainMessage();
            msg.obj = "我是模擬的網絡數據";
            handler.sendMessage(msg);
            System.out.println("開始發送網絡數據：");
            //暫時還不清楚為什么這個線程里使用Toast的時候一定要加上Looper.prepare()，否則就報錯
//            Looper.prepare();
//            Toast.makeText(SecActivity.this, Thread.currentThread().getName()+"開始發送網絡數據:", 100).show();
        }
    }
    
    class MainToWorkThread extends Thread{
        @Override
        public void run() {
            Looper.prepare();
            handler_main_to_work = new Handler(){
                @Override
                public void handleMessage(Message msg) {
                    String msg_get = (String)msg.obj;
//                    handler_main_to_work.sendMessage(msg);
                    Toast.makeText(SecActivity.this, Thread.currentThread().getName()+",MaintoWorkHandler.handleMessage()開始接收消息:"+msg_get, 100).show();
                }
            };
            Message msg = handler_main_to_work.obtainMessage();
            String msg_get = (String) msg.obj;
            System.out.println("MainToWorkThread獲取到的消息："+msg_get);
            Looper.loop();
        }
    }

    private void initClicks() {
        btn_main_to_work.setOnClickListener(this);
        btn_work_to_main.setOnClickListener(this);
    }

    private void initViews() {
        btn_main_to_work = (Button) findViewById(R.id.id_btn_w_to_main);
        btn_work_to_main = (Button) findViewById(R.id.id_btn_main_to_w);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.id_btn_w_to_main:
            new WorktoMainThread().start();
            break;
        case R.id.id_btn_main_to_w:
            Message msg = handler_main_to_work.obtainMessage();
            msg.obj = "我是點擊的時候發送給子線程的消息";
            handler_main_to_work.sendMessage(msg);
            break;
        default:
            break;
        }
    }
}