<system.webServer>

    <!--IIS7/7.5上必须加这个配置,否则访问报错-->

    <modules runAllManagedModulesForAllRequests="true">

      <remove name="WebDAVModule"/>

    </modules>

    <validation validateIntegratedModeConfiguration="false"/>

    <!--以下配置为了让IIS7+支持Put/Delete方法(CORS)-->

    <httpProtocol>

      <customHeaders>

        <!--<add name="Access-Control-Allow-Origin" value="http://*.com" />-->

        <!--<add name="Access-Control-Allow-Origin" value="http://local*:49356" />-->

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

        <add name="Access-Control-Allow-Headers" value="Accept,Content-Type,X-Requested-With"/>

        <add name="Access-Control-Allow-Credentials" value="true"/>

        <!-- 跨域session保持 -->

      </customHeaders>

    </httpProtocol>

 <handlers>

      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_64bit"/>

      <remove name="ExtensionlessUrlHandler-ISAPI-4.0_32bit"/>

      <remove name="WebDAV"/>

      <remove name="OPTIONSVerbHandler"/>

      <!--跨域重点配置-->

      <add name="ExtensionlessUrlHandler-ISAPI-4.0_32bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework\v4.0.30319\aspnet_isapi.dll" resourceType="Unspecified" requireAccess="Script" preCondition="classicMode,runtimeVersionv4.0,bitness32" responseBufferLimit="0"/>

      <add name="ExtensionlessUrlHandler-ISAPI-4.0_64bit" path="*." verb="GET,HEAD,POST,DEBUG,PUT,DELETE,PATCH,OPTIONS" modules="IsapiModule" scriptProcessor="%windir%\Microsoft.NET\Framework64\v4.0.30319\aspnet_isapi.dll" resourceType="Unspecified" requireAccess="Script" preCondition="classicMode,runtimeVersionv4.0,bitness64" responseBufferLimit="0"/>

    </handlers>
</system.webServer>

<remove name="OPTIONSVerbHandler"/>

 //cros  跨域请求配置

    protected void Application_BeginRequest(object sender, EventArgs e)

    {

        string origin = HttpContext.Current.Request.Headers["Origin"];

        if (origin != null)

        {

            HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", origin);

        }

        else

        {

            HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*");

        }

        if (HttpContext.Current.Request.HttpMethod == "OPTIONS" && Request.RawUrl.ToLower().Contains(".asmx/"))

        {

            HttpContext.Current.Response.End();

        }

    }