Web API应用架构在Winform混合框架中的应用（2）--自定义异常结果的处理

错误时微信会返回错误码等信息，JSON数据包示例如下（该示例为AppID无效错误）:



{"errcode":40013,"errmsg":"invalid appid"}

    /// <summary>
    ///接口返回的错误信息/// </summary>
    public classBaseResultJson

    {/// <summary>
        ///错误代码/// </summary>
        public int errcode { get; set; }/// <summary>
        ///如果不成功，返回的错误信息/// </summary>
        public string errmsg { get; set; }/// <summary>
        ///是否成功/// </summary>
        public bool success { get; set; }

    }

            //如果没有通过，则抛出异常，由异常过滤器统一处理
            if (!result.success)

            {throw newMyApiException(result.errmsg, result.errcode);

            }

    /// <summary>
    ///所有接口基类/// </summary>
[ExceptionHandling]public class BaseApiController : ApiController

    /// <summary>
    ///API自定义错误过滤器属性/// </summary>
    public classExceptionHandlingAttribute : ExceptionFilterAttribute

    {/// <summary>
        ///统一对调用异常信息进行处理，返回自定义的异常信息/// </summary>
        /// <param name="context">HTTP上下文对象</param>
        public override voidOnException(HttpActionExecutedContext context)

        {//自定义异常的处理
            MyApiException ex = context.Exception asMyApiException;if (ex != null)

            {throw new HttpResponseException(newHttpResponseMessage(HttpStatusCode.InternalServerError)

                {//封装处理异常信息，返回指定JSON对象
                    Content = new StringContent(new BaseResultJson(ex.Message, false, ex.errcode).ToJson()),

                    ReasonPhrase= "Exception"});



            }//记录关键的异常信息
Debug.WriteLine(context.Exception);//常规异常的处理
            string msg = string.IsNullOrEmpty(context.Exception.Message) ? "接口出现了错误，请重试或者联系管理员": context.Exception.Message;throw new HttpResponseException(newHttpResponseMessage(HttpStatusCode.InternalServerError)

            {

                Content= newStringContent(msg),

                ReasonPhrase= "Critical Exception"});

        }

    }

{"errcode":404,"errmsg":"请求的资源不支持 http 方法“POST”。","success":false}

            HttpHelper helper = newHttpHelper();

            helper.ContentType= "application/json";string content = helper.GetHtml(url, postData, true);

            VerifyErrorCode(content);



            T result= JsonConvert.DeserializeObject<T>(content);return result;

                BaseResultJson errorResult = JsonConvert.DeserializeObject<BaseResultJson>(content);//非成功操作才记录异常，因为有些操作是返回正常的结果（{"errcode": 0, "errmsg": "ok"}）
                if (errorResult != null && !errorResult.success)

                {string error = string.Format("请求发生错误！错误代码：{0}，说明：{1}", (int)errorResult.errcode, errorResult.errmsg);

                    LogTextHelper.Error(errorResult.ToJson());throw new Exception(error);//抛出错误
                }

    public static classWebApiConfig

    {public static voidRegister(HttpConfiguration config)

        {

    

            ..............



            config.MessageHandlers.Add(new CustomErrorMessageDelegatingHandler());

    /// <summary>
    ///API自定义错误消息处理委托类。///用于处理访问不到对应API地址的情况，对错误进行自定义操作。/// </summary>
    public classCustomErrorMessageDelegatingHandler : DelegatingHandler

    {protected override Task<HttpResponseMessage>SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)

        {return base.SendAsync(request, cancellationToken).ContinueWith<HttpResponseMessage>((responseToCompleteTask) =>{

                HttpResponseMessage response=responseToCompleteTask.Result;

                HttpError error= null;if (response.TryGetContentValue<HttpError>(outerror))

                {//添加自定义错误处理//error.Message = "Your Customized Error Message";
}if (error != null)

                {//获取抛出自定义异常，有拦截器统一解析
                    throw new HttpResponseException(newHttpResponseMessage(HttpStatusCode.NotFound)

                    {//封装处理异常信息，返回指定JSON对象
                        Content = new StringContent(new BaseResultJson(error.Message, false, 404).ToJson()),

                        ReasonPhrase= "Exception"});

                }else{returnresponse;

                }

            });

        }

    }

{"errcode":404,"errmsg":"找不到与请求 URI“http://localhost:9001/api/SystemType/Delete?signature=72f8d706c79dc14d70fc3f080d4706748d754021&timestamp=1443194061&nonce=0.650359861866666663&appid=website_9A39C2A8&token=eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJpc3MiOiIxIiwiaWF0IjoxNDQzMTk0MDM4LCJqdGkiOiI1YmEyYmE5Ni0yZTA4LTQ1ZTgtYTAwNy01MmY3OTkzYTg2NzEiLCJuYW1lIjoiYWRtaW4iLCJjaGFubmVsIjoiMCIsInNoYXJlZGtleSI6IjEyMzRhYmNkIn0.RRXQmmSCJzDK5Or6rmBL5wjd-YIJoEQFc0pOzqhR6IU”匹配的 HTTP 资源。","success":false}