Android中属性动画Property Animation使用示例(二)

package cc.cn;

import android.animation.ValueAnimator;
import android.animation.ValueAnimator.AnimatorUpdateListener;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup.MarginLayoutParams;
import android.widget.Button;
/**
* Demo描述:
* 属性动画中ValueAnimator使用实例
* 利用ValueAnimator使控件发生位移(变化Margin值)
*
* ValueAnimator是Property Animation很重要的一个类
* ValueAnimator可跟踪记录对象属性已经变化的时间及当前这个时间点的值
*
* 参考资料:
* 1 http://blog.csdn.net/linmiansheng/article/details/18716841 * 2 http://blog.csdn.net/linmiansheng/article/details/18763987 * 3 关于属性动画的中文文档,请参见:
*   http://blog.csdn.net/think_soft/article/details/7703684 *   http://wiki.eoeandroid.com/Property_Animation *   Thank you very much
*
*/
public class MainActivity extends Activity {
private Button mValueAnimatorButton;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
init();
}

private void init(){
mValueAnimatorButton=(Button) findViewById(R.id.valueAnimatorButton);
//ValueAnimator.ofInt(int,int)设定了值的变化范围
final ValueAnimator valueAnimator=ValueAnimator.ofInt(20,100);
//利用AnimatorUpdateListener监听动画的执行
valueAnimator.addUpdateListener(new AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator va) {
//得到动画当前执行的值
//这些值均在(20,100)之间
Integer animatedValue = (Integer)va.getAnimatedValue();
System.out.println("animatedValue="+animatedValue);
MarginLayoutParams marginLayoutParams = (MarginLayoutParams) mValueAnimatorButton.getLayoutParams();
marginLayoutParams.leftMargin = animatedValue;
//不断修改Button的Margin值
mValueAnimatorButton.setLayoutParams(marginLayoutParams);
}
});
valueAnimator.setDuration(2000);
//valueAnimator.setRepeatCount(1);
//valueAnimator.setRepeatMode(ValueAnimator.REVERSE);
valueAnimator.setTarget(mValueAnimatorButton);

mValueAnimatorButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
valueAnimator.start();
}
});
}
}

<?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" >

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

</LinearLayout>