Android:UI更新方法三:Handler+Worker Thread

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity" >

<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="50dp"
android:background="#ff999999"
android:text="@string/hello_world" />

<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />

</LinearLayout>

package com.example.updateui;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity
{
private static final String TAG = MainActivity.class.getSimpleName();
private static final int REFRESH_ACTION = 1;
private Button mButton;
private TextView mTextView;
private int mCount = 0;

@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextView = (TextView) findViewById(R.id.textView1);
mButton = (Button) findViewById(R.id.button1);
mButton.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View arg0)
{
// TODO Auto-generated method stub
new Thread(new Runnable() // 工作线程刷新UI
{

@Override
public void run()
{
// TODO Auto-generated method stub
while (!Thread.currentThread().interrupted())
{
/** 这段代码也可以：
* Message msg = new Message(); msg.what =
* MainActivity.REFRESH_ACTION;
* mHandler.sendMessage(msg);
*/
//发送消息到UI线程进行刷新
mHandler.obtainMessage(MainActivity.REFRESH_ACTION).sendToTarget();
try
{
Thread.sleep(1000);
}
catch (InterruptedException e)
{
Thread.currentThread().interrupt();
}
}
}

}).start();

}
});
}

private Handler mHandler = new Handler()
{
@Override
public void handleMessage(Message msg)
{
// 处理消息
switch (msg.what)
{
case MainActivity.REFRESH_ACTION:
mCount++;
mTextView.setText("I'm updated:" + mCount);// 更新UI，这里已经是UI线程
Log.i(TAG, "handleMessage");
break;
}
super.handleMessage(msg);
}

};

@Override
public boolean onCreateOptionsMenu(Menu menu)
{
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}

}