这是我到目前为止所尝试的。
 <rule name="https main site to http" stopProcessing="true">
       <match url="^(.*)$" ignoreCase="true" />
       <conditions>
            <add input="{HTTPS}" pattern="Off" />
       </conditions>
       <action type="Redirect" url="http://{HTTP_HOST}/{REQUEST_URI}" />
 </rule>