在ASP.Net webapi中可以使用 Microsoft.AspNet.WebApi.Cors 来实现：
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
// New code
config.EnableCors();
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
}
}
[EnableCors(origins: "http://mywebclient.azurewebsites.net", headers: "*", methods: "*")]
public class TestController : ApiController
{
// Controller methods not shown...
}
但在MVC中不能使用这个，需要自定义一个类：
public class AllowCrossSiteJsonAttribute: ActionFilterAttribute
{
private string[] _domains;
public AllowCrossSiteJsonAttribute(string domain)
{
_domains= new string[] { domain };
}
public AllowCrossSiteJsonAttribute(string[] domains)
{
_domains = domains;
}
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
var context = filterContext.RequestContext.HttpContext;
var host = context.Request.UrlReferrer?.Host;
if (host != null && _domains.Contains(host))
{
filterContext.RequestContext.HttpContext.Response.AddHeader("Access-Control-Allow-Origin", "*");
}
base.OnActionExecuting(filterContext);
}
}
在被访问的控制器上加上AllowCrossSiteJson：
[AllowCrossSiteJson("localhost")]
public JsonResult Index()
{
var holidays = new List<Holiday>
{
new Holiday
{
Title="2 Weeks in Rhodes",
Price=,
ImgUrl="http://media.wiley.com/product_data/coverImage/84/04702927/0470292784.jpg"
},
new Holiday
{
Title="1 Weeks in Barbados",
Price=,
ImgUrl="http://media.wiley.com/product_data/coverImage/84/04702927/0470292784.jpg"
}
};
return Json(holidays, JsonRequestBehavior.AllowGet);
}