HandlerActivity.java

package com.lx;

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.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;

public class HandlerActivity extends Activity {

private TextView textView;
private MyHandler myHandler;
private Button button;
private ProgressBar progressBar;
private MyThread m = new MyThread();
/** Called when the activity is first created. */

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.handlermain);
textView = (TextView) findViewById(R.id.text);
button = (Button) findViewById(R.id.startButton);
progressBar = (ProgressBar) findViewById(R.id.bar);
progressBar.setMax(100);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
myHandler = new MyHandler();
new Thread(m).start();
System.out.println("onCreate--The Thread is: "
+ Thread.currentThread().getId());
}
});
}

// 在对UI进行更新时，执行时所在的线程为主UI线程
class MyHandler extends Handler {// 继承Handler类时，必须重写handleMessage方法
public MyHandler() {
}

public MyHandler(Looper loop) {
super(loop);
}

@Override
public void handleMessage(Message msg) {// 执行接收到的通知，此时执行的顺序是按照队列进行，即先进先出
System.out.println("handleMessage--The ThreadId is: "
+ Thread.currentThread().getId());
super.handleMessage(msg);
Bundle b = msg.getData();
String textStr0 = textView.getText().toString();
String textStr1 = b.getString("textStr");
HandlerActivity.this.textView.setText(textStr0 + " " + textStr1);// 更改TextView中的值
int barValue = b.getInt("barValue");
HandlerActivity.this.progressBar.setProgress(barValue);
}

}

// 该线程将会在单独的线程中运行

class MyThread implements Runnable {
int i = 1;
@Override
public void run() {
while (i < 11) {
System.out.println("MyThread--run ThreadId is: "
+ Thread.currentThread().getId());
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Message msg = new Message();
Bundle b = new Bundle();
b.putString("textStr", "线程运行" + i + "次");
b.putInt("barValue", i * 10);
i++;
msg.setData(b);
HandlerActivity.this.myHandler.sendMessage(msg);// 通过sendMessage向Handler发送更新UI的消息
}
}
}

}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent" >

<TextView android:id="@+id/text"
android:layout_width="fill_parent"
android:layout_height="wrap_content"

>
</TextView>

<Button android:id="@+id/startButton"
android:layout_width="fill_parent"
android:layout_height="wrap_content"

>
</Button>

<ProgressBar android:id="@+id/bar"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>


</ProgressBar>

</LinearLayout>