如何在Win8应用程序中使用代理连接HTTPS

我可以通过http连接，但无法连接https

HttpRequestException消息：

发送请求时出错。 System.Net.WebExceptionStatus.TrustFailure

HttpClientHandler clienthandler = new HttpClientHandler();
        HttpClient client = new HttpClient(clienthandler);
        HttpRequestMessage req = new HttpRequestMessage(HttpMethod.Post, "https://www.google.com.hk/");
        req.Headers.Referrer = new Uri("https://www.google.com.hk/");
        HttpResponseMessage mes = await client.SendAsync(req);