Android AlertDialog淡入淡出动画

1.将下面的2个xml动画文件放入res/anim文件夹

1.1dialog_enter 进入动画

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<scale
android:interpolator= "@android:anim/decelerate_interpolator"
android:fromYScale="1.3"
android:toYScale="1"
android:fromXScale="1.3"
android:toXScale="1"
android:pivotX="50%"
android:pivotY="50%"
android:startOffset="0"
android:duration="200"
/>

<alpha
android:fromAlpha="0.0"
android:toAlpha="1.0"
android:duration="300"
/>

</set>

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
<scale
android:interpolator= "@android:anim/decelerate_interpolator"
android:fromYScale="1"
android:toYScale="1.3"
android:fromXScale="1"
android:toXScale="1.3"
android:pivotX="50%"
android:pivotY="50%"
android:startOffset="0"
android:duration="300"
/>

<alpha
android:fromAlpha="1.0"
android:toAlpha="0.0"
android:duration="300"
/>
</set>

<!-- dialog动画 -->
<style name="dialog_style" parent="android:Animation">
<item name="android:windowEnterAnimation">@anim/dialog_enter</item>
<item name="android:windowExitAnimation">@anim/dialog_exit</item>
</style>

@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
// TODO Auto-generated method stub

alertDialog = new AlertDialog.Builder(getActivity(), R.style.Theme_Transparent).create();
Window window = alertDialog.getWindow();
window.setGravity(Gravity.CENTER);
window.setWindowAnimations(R.style.dialog_style);
View view = View.inflate(getActivity(), R.layout.recommend_fragment, null);
initView(view);

alertDialog.setView(view, 0, 0, 0, 0);
return alertDialog;
}