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)
        {
          
        }