在web.config里system.webServer节点添加一下代码
<httpProtocol>
<customHeaders>
<!-- 跨域 -->
<remove name="Access-Control-Allow-Origin" />
<remove name="Access-Control-Allow-Headers" />
<remove name="Access-Control-Allow-Methods" />
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="Content-Type" />
<add name="Access-Control-Allow-Methods" value="*" />
</customHeaders>
</httpProtocol>