android activity 切换动画问题

我自定义Activity切换动画，但是没有效果，求助时什么问题？用的Theme，没有用OverridePendingAnimation
这是代码

<activity
            android:name=".activities.CardCommentActivity"
            android:screenOrientation="portrait"
            android:theme="@style/cardCommentActivityStyle"
            android:windowSoftInputMode="adjustResize" />

 <style name="cardCommentActivityStyle" parent="AppTheme.NoActionBar">
        <item name="android:windowAnimationStyle">@style/commentActivityAnimation</item>
    </style>

    <style name="commentActivityAnimation" parent="@android:style/Animation.Activity">
        <item name="android:activityOpenEnterAnimation">@anim/activity_slide_in</item>
        <item name="android:activityOpenExitAnimation">@anim/activity_slide_out</item>
        <item name="android:activityCloseEnterAnimation">@anim/activity_slide_in</item>
        <item name="android:activityCloseExitAnimation">@anim/activity_slide_out</item>
    </style>

http://www.cnblogs.com/sunzn/p/3854009.html