联系 self-hosted WebApi 服务时出现 CORS Pre-flight 错误

Question

当 Web 门户联系 self-hosted WebAPI 服务时出现此错误，该服务位于 Web 门户服务器以外的其他服务器：

Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'someportaldomain' is therefore not allowed access.

self-hosted 服务总是在每个响应中 return "Access-Control-Allow-Origin" header，但是如果浏览器决定在调用 url, 用户在 js 控制台上得到这个错误。

Answer 1

我post这里的答案，因为我没有找到任何直接的答案，不得不从几个post中把它拉出来。

解决方案是将 Options 方法添加到自托管服务，如下所示：

[ServiceContract]    
public interface IACT_HttpService
{
    //[FaultContract(typeof(ValidationFault))]
    [WebInvoke(Method = "OPTIONS", UriTemplate = "*")]
    void GetOptions();

  //My other methods
  ...
}


public class ACT_HttpService : IACT_HttpService
{
    //Adjust this method to restrict the origin as needed
    public void GetOptions()
    {
        log.Debug("Get options fired");
        //These headers are handling the "pre-flight" OPTIONS call sent by the browser
        WebOperationContext.Current.OutgoingResponse.Headers.Add("Access-Control-Allow-Methods", "POST,GET,PUT,DELETE,OPTIONS");
        //Add here any special header you have
        WebOperationContext.Current.OutgoingResponse.Headers.Add("Access-Control-Allow-Headers", "X-Requested-With,Content-Type");
        WebOperationContext.Current.OutgoingResponse.Headers.Add("Access-Control-A}llow-Origin", "*");            

        WebOperationContext.Current.OutgoingResponse.StatusCode = System.Net.HttpStatusCode.OK;
    }

联系 self-hosted WebApi 服务时出现 CORS Pre-flight 错误

CORS Pre-flight error when contacting self-hosted WebApi service

asp.net

asp.net-mvc

cors

preflight