C# 获取客户端IP地址

/// <summary>
/// 获取客户端IP地址
/// </summary>
/// <returns></returns>
public static string GetClientIP()
{
string result = HttpContext.Current.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];
if (null == result || result == String.Empty)
{
result = HttpContext.Current.Request.ServerVariables["REMOTE_ADDR"];
}

if (null == result || result == String.Empty)
{
result = HttpContext.Current.Request.UserHostAddress;
}
return result;
}