图片缓慢放大

MainActivity.java

package com.example.mysamll.app.imgscale;

import android.app.Activity;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Animation animation = AnimationUtils.loadAnimation(this,R.anim.enlarge);
        animation.setFillAfter(true);
        ((ImageView) findViewById(R.id.my_img)).startAnimation(animation);
        animation.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {
                Toast.makeText(MainActivity.this,"stop!",Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });

    }
}

actity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.mysamll.app.imgscale.MainActivity">

    <ImageView
        android:id="@+id/my_img"
        android:src="@mipmap/bird"
        android:scaleType="fitXY"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</RelativeLayout>

/res/anim/enlarge.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:shareInterpolator="false">

    <scale
        android:duration="8000"
        android:fromXScale="1.0"
        android:fromYScale="1.0"
        android:pivotX="50%"
        android:pivotY="50%"
        android:toXScale="1.3"
        android:toYScale="1.3"
        />

</set>