解决js,webservice 跨域问题的，服务器端添加代码

public class Global : System.Web.HttpApplication
    {
        protected void Application_BeginRequest(object sender, EventArgs e)
        {
            if (HttpContext.Current != null && HttpContext.Current.Response != null)
            {
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*"); // take care

                if (HttpContext.Current.Request.HttpMethod == "OPTIONS")
                {
                    HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS");
                    HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "Content-Type, Authorization, Accept,X-Requested-With");
                    HttpContext.Current.Response.End();
                }
            }
        }

    }