使用 “android.support.PARENT_ACTIVITY”属性定义默认的返回。
···

<activity android:label="@string/app_name" android:name=".activity.HomeActivity" android:launchMode="singleTask" android:screenOrientation="portrait" android:configChanges="keyboardHidden|orientation" />
    <activity android:label="@string/search_title" android:name=".activity.SearchActivity" android:launchMode="singleTop" android:screenOrientation="portrait" android:configChanges="keyboardHidden|orientation" android:parentActivityName=".activity.HomeActivity">
        <intent-filter>
            <action android:name="android.intent.action.SEARCH" />
        </intent-filter>
        <meta-data android:name="android.app.searchable" android:resource="@xml/searchable" />
        <meta-data android:name="android.support.PARENT_ACTIVITY" android:value=http://www.mamicode.com/".activity.HomeActivity" />> 
···
定义默认的android的返回路径