ajax跨域请求Webservice：已阻止跨源请求：CORS 头缺少 'Access-Control-Allow-Origin'

在Web.Config中加入

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