解决api 跨域 webconfig添加节点

<system.webServer>
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*"/>
<add name="Access-Control-Allow-Methods" value="GET,POST,PUT,DELETE,OPTIONS"/>
<add name="Access-Control-Allow-Headers" value="Content-Type"/>
</customHeaders>
</httpProtocol>
</system.webServer>