Android Handler简单例子

package com.example.handler;import android.os.Bundle;import android.app.Activity;import android.app.ProgressDialog;import android.content.res.Resources;import android.os.Handler;import android.os.Message;import android.util.Log;import android.view.View;import android.widget.Button;public class MainActivity extends Activity {        //声明变量    private Button b1;    private ProgressDialog pd;        //定义Handler对象    private Handler handler =new Handler(){        @Override        //当有消息发送出来的时候就执行Handler的这个方法        public void handleMessage(Message msg){            super.handleMessage(msg);            //只要执行到这里就关闭对话框            pd.dismiss();        }    };            /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);            Resources res=  this.getResources();        //查看UI组件所在的线程名        Log.i("tag", "onCreate()-->"+Thread.currentThread().getName());                //定义UI组件        b1= (Button)findViewById(R.id.Button01);        //给按钮绑定单击事件监听器        b1.setOnClickListener(new View.OnClickListener() {                        @Override            public void onClick(View v) {                //点击按钮后去处理长耗时操作                processThread();            }        });    }            private void processThread(){                //构建一个下载进度条        pd= ProgressDialog.show(MainActivity.this, "下载文件", "正在下载……");        Log.i("tag", "processThread()-->"+Thread.currentThread().getName());                new Thread(){                        @Override            public void run(){                Log.i("tag", "run()-->"+Thread.currentThread().getName());                //在新线程里执行长耗时方法                longTimeMethod();                //执行完毕后给handler发送一个空消息                handler.sendEmptyMessage(0);            }                    }.start();    }        //模拟下载文件的长耗时方法    private void longTimeMethod(){        try {            Log.i("tag", "longTimeMethod-->"+Thread.currentThread().getName());            Thread.sleep(10000);        } catch (InterruptedException e) {            e.printStackTrace();        }    }}

转自：http://android.yaohuiji.com/archives/770