Web.Config 重定向规则，IIS 会根据里面的规则自动重定向；

# web redirect to Home page
<rule name="Root Hit Force HTTPS Redirection" enabled="true" stopProcessing="true">
    <match url="^$" ignoreCase="false" />
    <conditions>
        <add input="{HTTPS}" pattern="^OFF$" />
        <add input="{HTTP_METHOD}" pattern="GET" />
    </conditions>
    <action type="Redirect" url="https://{HTTP_HOST}/en/" redirectType="Permanent" />
</rule>
<rule name="Root Hit Force HTTPS root" enabled="true" stopProcessing="true">
    <match url="^$" />
    <conditions>
        <add input="{HTTP_METHOD}" pattern="GET" />
    </conditions>
    <action type="Redirect" url="https://{HTTP_HOST}/en/" redirectType="Permanent" />
</rule>