把下面的代码放在web.config文件中的 system.webServer 节点下
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="*" />
<add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE" />
</customHeaders>
</httpProtocol>