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>