android 缩放控制（ZoomControls）

在main.xml中

<?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"

android:gravity="center_horizontal">

<TextView

android:id="@+id/text"

android:layout_marginTop="15dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:textSize="20dp"

android:text="不积跬步无以至千里" />

<ZoomControls

android:id="@+id/zoomcontrols"

android:layout_marginTop="15dp"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:gravity="bottom"/>

</LinearLayout>

在MyZoomControlsDemo.java程序中

package com.li.zoomcontrols;

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 MyZoomControlsDemo extends Activity {

private TextView text = null;

private ZoomControls zoomControls = null;

private int size = 20; //保存文字大小的变量

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

super.setContentView(R.layout.main);

this.text = (TextView)super.findViewById(R.id.text);

this.zoomControls = (ZoomControls)super.findViewById(R.id.zoomcontrols);

this.zoomControls.setOnZoomInClickListener(new OnZoomInClickListenerImpl());

this.zoomControls.setOnZoomOutClickListener(new OnZoomOutClickListenerImpl());

}

private class OnZoomInClickListenerImpl implements OnClickListener{

public void onClick(View v) {

MyZoomControlsDemo.this.size = size + 2;

MyZoomControlsDemo.this.text.setTextSize(size);

}

}

private class OnZoomOutClickListenerImpl implements OnClickListener{

public void onClick(View v) {

MyZoomControlsDemo.this.size = size - 2;

MyZoomControlsDemo.this.text.setTextSize(size);

}

}

}