下面是一个功能强大的改造的例子：
可以实现以下需求：
1.两个手指进行缩放布局
2.所有子控件也随着缩放，
3.子控件该有的功能不能丢失（像button有可被点击的功能，缩放后不能丢失该功能）
运行效果图：
java代码如下
MainActivity.java:
public class MainActivity extends ActionBarActivity {
private ScaleGestureDetector mScaleGestureDetector = null;
private View view;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// setContentView(R.layout.test);
view = View.inflate(this, R.layout.activity_main, null);
setContentView(view);
mScaleGestureDetector = new ScaleGestureDetector(this,
new ScaleGestureListener());
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// 返回给ScaleGestureDetector来处理
return mScaleGestureDetector.onTouchEvent(event);
}
public class ScaleGestureListener implements
ScaleGestureDetector.OnScaleGestureListener {
private float scale;
private float preScale = 1;// 默认前一次缩放比例为1
@Override
public boolean onScale(ScaleGestureDetector detector) {
float previousSpan = detector.getPreviousSpan();
float currentSpan = detector.getCurrentSpan();
if (currentSpan < previousSpan) {
// 缩小
// scale = preScale-detector.getScaleFactor()/3;
scale = preScale - (previousSpan - currentSpan) / 1000;
} else {
// 放大
// scale = preScale+detector.getScaleFactor()/3;
scale = preScale + (currentSpan - previousSpan) / 1000;
}
// 缩放view
ViewHelper.setScaleX(view, scale );// x方向上缩小
ViewHelper.setScaleY(view, scale );// y方向上缩小
return false;
}
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
// 一定要返回true才会进入onScale()这个函数
return true;
}
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
preScale = scale;//记录本次缩放比例
}
}
}
布局文件(activity_main.xml)：
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:background="@drawable/home_tools"
> <TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="测试" /> <ImageView
android:id="@+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/abc_ic_voice_search_api_holo_light" /> <ImageButton
android:id="@+id/imageButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/selector_button2" /> <ImageButton
android:id="@+id/imageButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="@drawable/selector_button1"
android:layout_gravity="center"
/> </LinearLayout>
selector_button1.xml：
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
<item android:drawable="@drawable/home_tools" android:state_pressed="true"></item>
<item android:drawable="@drawable/home_*"></item>
</selector>
selector_button2.xml
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android" >
<item android:drawable="@drawable/home_sysoptimize" android:state_pressed="true"></item>
<item android:drawable="@drawable/home_taskmanager"></item>
</selector>
如果想要整个布局能够移动，可以看下面的帖子：