1、Web.config 设置跨域

<httpProtocol>

  <customHeaders>

    <add name="Access-Control-Allow-Origin" value="*" />

    <add name="Access-Control-Allow-Headers" value="Content-Type" />

    <add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE,OPTIONS" />

  </customHeaders>

</httpProtocol>

2、Global.asax中配置OPTIONS

protected void Application_BeginRequest()

{

    if (Request.Headers.AllKeys.Contains("Origin") && Request.HttpMethod == "OPTIONS")

    {

        Response.Flush();

    }

}