<span>public<span> <span>class<span> <span>JsonExceptionFilterAttribute<span> <span>:<span> <span>FilterAttribute<span>,<span> <span>IExceptionFilter<span>
<span>{<span>
<span>public<span> <span>void<span> <span>OnException<span>(<span>ExceptionContext<span> filterContext<span>)<span>
<span>{<span>
<span>if<span> <span>(<span>filterContext<span>.<span>RequestContext<span>.<span>HttpContext<span>.<span>Request<span>.<span>IsAjaxRequest<span>())<span>
<span>{<span>
filterContext<span>.<span>HttpContext<span>.<span>Response<span>.<span>StatusCode<span> <span>=<span> <span>500<span>;<span>
filterContext<span>.<span>ExceptionHandled<span> <span>=<span> <span>true<span>;<span>
filterContext<span>.<span>Result<span> <span>=<span> <span>new<span> <span>JsonResult<span>
<span>{<span>
<span>Data<span> <span>=<span> <span>new<span>
<span>{<span>
errorMessage <span>=<span> filterContext<span>.<span>Exception<span>.<span>Message<span>
<span>},<span>
<span>JsonRequestBehavior<span> <span>=<span> <span>JsonRequestBehavior<span>.<span>AllowGet<span>
<span>};<span>
<span>}<span>
<span>}<span>
<span>}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
之后，我们要给FuckJson()方法加上这个“特征”（Attribute在C#中最好不要翻译为属性），然后故意抛个错做测试。修改后的方法如下：
复制代码 代码如下:
<span>[<span>JsonExceptionFilterAttribute<span>]<span>
<span>public<span> <span>JsonResult<span> <span>FuckJson<span>()<span>
<span>{<span>
<span>try<span>
<span>{<span>
<span>throw<span> <span>new<span> <span>Exception<span>(<span>"oh shit!"<span>);<span>
<span>return<span> <span>new<span> <span>JsonResult<span>()<span>
<span>{<span>
<span>Data<span> <span>=<span> <span>new<span> <span>List<span><string><span>()<span> <span>{<span> <span>"fuck"<span>,<span> <span>"shit"<span> <span>},<span> <span>JsonRequestBehavior<span> <span>=<span> <span>JsonRequestBehavior<span>.<span>AllowGet<span>
<span>};<span>
<span>}<span>
<span>catch<span> <span>(<span>Exception<span> ex<span>)<span>
<span>{<span>
<span>throw<span> ex<span>;<span>
<span>}<span>
<span>}</span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span></span>
捕获异常后，你也可以先记一下log、或是根据你自己的需要处理一下这个异常，然后再throw。
最后我们的AJAX请求代码也得做修改，增加一个error的处理：
复制代码 代码如下: