Allow Cross-origin resource sharing - CORS - In WebApi2 In Global.asax.cs

Allow_CORS_In_WebApi2_In_Global.asax.cs

using System.Linq;
        
private readonly string[] authorizedSites = new string[]
{
  "https://site1.com",
  "https://site2.com"
};

private void SetAccessControlAllowOrigin() 
{
  string origin = HttpContext.Current.Request.Headers.Get("Origin");

  if (authorizedSites.Contains(origin)) 
      HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", origin);
}

protected void Application_BeginRequest() 
{
  SetAccessControlAllowOrigin();
}