面对的问题，在淡化动画在android

Question

我正在做一个简单的alpha动画的例子，在点击一个按钮的图像显示为褪色，问题是，当我运行这个，并在点击按钮的应用程序停止。有人能告诉我我哪里做错了吗?以下是我的代码:-

MainActivity.java

public class MainActivity extends ActionBarActivity {
private ImageView imageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageView=(ImageView)findViewById(R.id.image_view);
}
public void onAlphaButtonClick(){
Animation
 animation=AnimationUtils.loadAnimation(getApplicationContext()
,R.anim.alpha);
}

res/动物/alpha.xml

<?xml version="1.0" encoding="utf-8"?>
<alpha xmlns:android="http://schemas.android.com/apk/res/android">
android:duration="5000"
android:fromAlpha="0.25"
android:toAlpha="1.0"
</alpha>

activity_main.xml

<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"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:paddingBottom="@dimen/activity_vertical_margin"
android:orientation="vertical"
>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Alpha"
android:id="@+id/button"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true" />
<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/image_view"
android:src="@drawable/image"
android:layout_marginBottom="155dp"
android:layout_above="@+id/button"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true" />
</RelativeLayout>

Answer 1

<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Alpha"
android:id="@+id/button"
<!-- You need to add this line -->
android:onClick="onAlphaButtonClick"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true" />