system.webServer节点写配置
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="Content-Type,X-Requested-With" />
<add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE, OPTIONS" />
</customHeaders>
</httpProtocol>
默认会在网站的所有请求头部加上
当webconfig 配置了相关跨域的节点,在一般处理程序就不要再请求头部加上这些信息
否则会报错