--------------------------------------------AndroidManifest.xml----------------------------------
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.ch22"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="15" />
<application
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
--------------------------------------------Layout activity_main.xml-----------------------------
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/LinearLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<Button
android:id="@+id/btn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="Button"/>
</LinearLayout>
--------------------------------------------MainActivity.java--------------------------------------
package com.ch22;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
/**
*
* 项目名称：com.ch22
* 类名称：MainActivity
* 类描述：Handler
* 创建人：方勇
* 创建时间：2012-12-10 下午8:29:04
* Copyright (c) 方勇-版权所有
*/
public class MainActivity extends Activity {
private Button btn;
/* 更新UI主线程对象 */
private Handler handler = new Handler() {
/* 异步接受消息 */
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
/* 获取Map数据 */
Bundle bundle = msg.getData();
/* 取得颜色值 */
int color = bundle.getInt("color");
MainActivity.this.btn.setBackgroundColor(color);
Log.i("fy", "Handler=" + Thread.currentThread().getName());
}
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findView();
setListeners();
Log.i("fy", "MainHandler=" + Thread.currentThread().getName());
}
/* 实例化UI */
private void findView() {
this.btn = (Button) findViewById(R.id.btn);
}
/* 设置监听 */
private void setListeners() {
btn.setOnClickListener(new btnOnClickListener());
}
class btnOnClickListener implements OnClickListener {
public void onClick(View v) {
MyThread my = new MyThread();
/* 启动线程 */
new Thread(my).start();
}
};
class MyThread implements Runnable {
public void run() {
try {
Thread.sleep(3000);// 子线程睡眠3秒
} catch (InterruptedException e) {
e.printStackTrace();
}
/* 实例化消息 */
Message msg = new Message();
Bundle bundle = new Bundle();
bundle.putInt("color", Color.RED);
msg.setData(bundle);
/* 发送消息，告诉老大(主线程)请更新 */
MainActivity.this.handler.sendMessage(msg);
Log.i("fy", "MyThread=" + Thread.currentThread().getName());
}
};
}
--------------------------------------------结果-----------------------------------------------------
点击按钮前
点击按钮后的3秒,按钮变为红色
