使用webapi时有时会为了数据安全性加以访问者ip验证，就需要在API项目中进行处理

1. 获取访问者IP地址 代码直接上 不罗嗦

 /// <summary>
 /// 获取访问者IP地址
 /// </summary>
 /// <returns></returns>
 public static string GetHostAddress()
 {
       string userIP = "127.0.0.1";

       try
       {
           if (System.Web.HttpContext.Current == null || System.Web.HttpContext.Current.Request == null || System.Web.HttpContext.Current.Request.ServerVariables == null)
               return "";

           string CustomerIP = "";

           //CDN加速后取到的IP 
           CustomerIP = System.Web.HttpContext.Current.Request.Headers["Cdn-Src-Ip"];
           if (!string.IsNullOrEmpty(CustomerIP))
           {
               return CustomerIP;
           }

           CustomerIP = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];


           if (!String.IsNullOrEmpty(CustomerIP))
               return CustomerIP;

           if (System.Web.HttpContext.Current.Request.ServerVariables["HTTP_VIA"] != null)
           {
               CustomerIP = System.Web.HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
               if (CustomerIP == null)
                   CustomerIP = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
           }
           else
           {
               CustomerIP = System.Web.HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];

           }

           if (string.Compare(CustomerIP, "unknown", true) == 0)
               return System.Web.HttpContext.Current.Request.UserHostAddress;
           return CustomerIP;
       }
       catch { }

       return userIP;
   }
   /// <summary>
   /// 检查IP地址格式
   /// </summary>
   /// <param name="ip"></param>
   /// <returns></returns>
   public static bool IsIP(string ip)
   {
       return System.Text.RegularExpressions.Regex.IsMatch(ip, @"^((2[0-4]\d|25[0-5]|[01]?\d\d?)\.){3}(2[0-4]\d|25[0-5]|[01]?\d\d?)$");
   }

1. 给WebAPI 添加过滤

public class CheckSecurityFilter : AuthorizeAttribute
  {
        private HttpContext Context
        {
            get { return HttpContext.Current; }
        }
        public override void OnAuthorization(HttpActionContext actionContext)
        {
            //检查IP 
            if (!CheckIP())
            {
                 HandleUnauthorizedRequest(actionContext);
                Context.Response.Write("当前IP没有权限!");
                Context.Response.End();
            }
        }
   }

1. 3.