Global.asax.cs

gistfile1.txt

//taken from https://blogs.msmvps.com/kenlin/2018/01/18/2694/
protected void Application_BeginRequest(object sender, EventArgs e)
{
  if (HttpContext.Current.Request.HttpMethod == "OPTIONS")
  {
    //These headers are handling the "pre-flight" OPTIONS call sent by the browser
    HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE");
    HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Accept");
    HttpContext.Current.Response.AddHeader("Access-Control-Allow‌​-Credentials", "true");
    HttpContext.Current.Response.AddHeader("Access-Control-Max-Age", "1728000");
    HttpContext.Current.Response.End();
  }
}