android:zoomcontrols

package com.zoomcontrol;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.TextView;
import android.widget.ZoomControls;

public class ZoomControlActivity extends Activity {
private ZoomControls zoomControls;
static long size = 12;
private TextView text;

/*
* (non-Javadoc)
*
* @see android.app.Activity#onCreate(android.os.Bundle)
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.mian);
setTitle("ZoomControls");
zoomControls = (ZoomControls) findViewById(R.id.zoomcontrols);
text = (TextView) findViewById(R.id.text);
zoomControls.setOnZoomInClickListener(new OnClickListener() {
@Override
public void onClick(View v) {

size = size + 2;
text.setTextSize(size);
}
});
zoomControls.setOnZoomOutClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
size = size - 2;
text.setTextSize(size);
}
});
}
}

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

<TextView
android:id="@+id/text"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ZoomControls实例"
android:textSize="12px" />

<ZoomControls
android:id="@+id/zoomcontrols"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom" />

</LinearLayout>