布局添加动画效果

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:animateLayoutChanges="true"
    android:id="@+id/myLinearLayout"
    >


    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button2" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button3" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button4" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button5" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="New Button"
        android:id="@+id/button6" />
</LinearLayout>

public class MainActivity extends Activity{
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 找到我们设置的布局
        LinearLayout rootView = (LinearLayout)this.findViewById(R.id.myLinearLayout);

        ScaleAnimation as = new ScaleAnimation(0, 1, 0, 1);  // 缩放动画
        as.setDuration(5000); //动画时间5s

        // 布局动画控制器
        LayoutAnimationController lac = new LayoutAnimationController(as, 0.5f);
        lac.setOrder(LayoutAnimationController.ORDER_REVERSE); // 动画类型  从下往上  默认是从上往下
        /**
         LayoutAnimationController.ORDER_NORMAL;  //顺序显示
         LayoutAnimationController.ORDER_REVERSE; //反显示
         LayoutAnimationController.ORDER_RANDOM   //随机显示
         * */

        rootView.setLayoutAnimation(lac);

        System.out.println("onCreate");
    }
}