Web API 下的 ActionFilter 与 ExceptionFilter

本文重点会标红。

背景需求，在进入action之前做sign验证，以及反正错误时，记录log，返回错误的json形式信息。

#region  普通 ActionFilter add by caoheyang 20150319    /// <summary>    /// sign 以及参数合法性验证过滤器 add by caoheyang 20150318    /// </summary>    public class SignOpenApiAttribute : System.Web.Http.Filters.ActionFilterAttribute    {        /// <summary>        /// 重写OnActionExecuting方法   在进入控制器之前验证 sign以及 参数合法性信息 add by caoheyang 20150318        /// </summary>        /// <param name="actionContext"></param>        public override void OnActionExecuting(System.Web.Http.Controllers.HttpActionContext actionContext)        {            lock (actionContext)            {                dynamic paramodel = actionContext.ActionArguments["paramodel"]; //当前请求的参数对象                 if (actionContext.ModelState.Count > 0 || paramodel == null) //参数错误，请求中止                    actionContext.Response = actionContext.ActionDescriptor.ResultConverter.Convert                            (actionContext.ControllerContext, ResultModel<object>.Conclude(OrderApiStatusType.ParaError));                IGroupProvider groupProvider = new GroupProvider();                GroupApiConfigModel groupCofigInfo = groupProvider.GetGroupApiConfigByAppKey(paramodel.app_key, paramodel.v).Data;                if (groupCofigInfo != null && groupCofigInfo.IsValid == 1)//集团可用，且有appkey信息                {                    string signStr = groupCofigInfo.AppSecret + "app_key=" + paramodel.app_key + "timestamp" + paramodel.timestamp + "v=" + paramodel.v + groupCofigInfo.AppSecret;                    string sign = MD5.Encrypt(signStr);                    paramodel.group = ParseHelper.ToInt(groupCofigInfo.GroupId, 0);                    actionContext.ActionArguments["paramodel"] = paramodel; ;                    if (sign != paramodel.sign)   //sign错误，请求中止                        actionContext.Response = actionContext.ActionDescriptor.ResultConverter.Convert                            (actionContext.ControllerContext, ResultModel<object>.Conclude(OrderApiStatusType.SignError)); //此处标红需要与 apicontroller里应用fillter的action返回值一直。                }                else                    actionContext.Response = actionContext.ActionDescriptor.ResultConverter.Convert                           (actionContext.ControllerContext, ResultModel<object>.Conclude(OrderApiStatusType.SignError));  //sign错误，请求中止            }        }    }    #endregion    #region  ExceptionFilter add by caoheyang 20150319    /// <summary>    /// 自定义全局异常处理类  add by caoheyang 20150319   全局过滤器，记录log    /// </summary>    public class OpenApiHandleErrorAttribute : ExceptionFilterAttribute    {        /// <summary>        /// 重写异常处理方法 add by caoheyang 20150205  其次执行        /// </summary>        /// <param name="filterContext">上下文对象  该类继承于ControllerContext</param>        public override void OnException(HttpActionExecutedContext filterContext)        {            LogHelper.LogWriterFromFilter(filterContext.Exception);        }    }    /// <summary>  action过滤器，当内部代码发生异常时，改变当前的请求服务器端返回信息    /// 自定义action异常处理类,捕获异常，返回系统错误提示信息  add by caoheyang 20150319    /// </summary>    public class OpenApiActionErrorAttribute : ExceptionFilterAttribute    {        /// <summary>        /// 重写异常处理方法 add by caoheyang 20150205    首先执行          /// </summary>        /// <param name="filterContext">上下文对象  该类继承于ControllerContext</param>        public override void OnException(HttpActionExecutedContext filterContext)        {            filterContext.Response = filterContext.ActionContext.ActionDescriptor.ResultConverter.              Convert(filterContext.ActionContext.ControllerContext, ResultModel<object>.Conclude(OrderApiStatusType.SystemError));

            //此处标红需要与 apicontroller里应用fillter的action返回值一直。

} } #endregion

ApiController eg。

 // POSR: Order GetStatus    paramodel 固定 必须是 paramodel        /// <summary>        /// 订单状态查询功能  add by caoheyang 20150316        /// </summary>        /// <returns></returns>        [HttpPost]        [SignOpenApi] //sign验证过滤器 设计参数验证，sign验证 add by caoheyang 201503167        [OpenApiActionError] //异常过滤器 add by caoheyang 一旦发生异常，客户端返回系统内部错误提示        public ResultModel<object> GetStatus(ParaModel<GetStatusPM_OpenApi> paramodel)        {                  }