UWP 带有header的webrequest请求

 var url = new Uri("http://www.baidu.com", UriKind.Absolute);            var httpClient = new System.Net.Http.HttpClient();            httpClient.DefaultRequestHeaders.Add("apikey", "123456");            var reponse = await httpClient.GetStreamAsync(url);            var streamReader = new StreamReader(reponse, Encoding.UTF8);            var jsonString = streamReader.ReadToEnd();            var jsonObject = JsonObject.Parse(jsonString);
网址：https://msdn.microsoft.com/zh-cn/library/windows/apps/windows.ui.xaml.controls.webview.navigatewithhttprequestmessage.aspx