我已经在StackOverflow上阅读了十二个类似的问题,但是我似乎无法理解这一点。关于web.config和HandleErrorAttribute中的自定义错误节点,如何调用Error.cshtml?最终,这个问题的答案可能是已经存在的有关ASP.NET MVC错误处理的几个问题之一。但是,事实是,我不知道是哪一个。
Answers:
在您的Global.asax内部,您可以使用以下方法:
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new HandleErrorAttribute());
}
这会将HandleErrorAttribute注册为全局操作过滤器。这意味着此处理程序将自动应用于所有控制器操作。现在,通过查看源代码来看看如何实现此属性:
[SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes", Justification = "This attribute is AllowMultiple = true and users might want to override behavior.")]
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = true)]
public class HandleErrorAttribute : FilterAttribute, IExceptionFilter {
private const string _defaultView = "Error";
private readonly object _typeId = new object();
private Type _exceptionType = typeof(Exception);
private string _master;
private string _view;
public Type ExceptionType {
get {
return _exceptionType;
}
set {
if (value == null) {
throw new ArgumentNullException("value");
}
if (!typeof(Exception).IsAssignableFrom(value)) {
throw new ArgumentException(String.Format(CultureInfo.CurrentCulture,
MvcResources.ExceptionViewAttribute_NonExceptionType, value.FullName));
}
_exceptionType = value;
}
}
public string Master {
get {
return _master ?? String.Empty;
}
set {
_master = value;
}
}
public override object TypeId {
get {
return _typeId;
}
}
public string View {
get {
return (!String.IsNullOrEmpty(_view)) ? _view : _defaultView;
}
set {
_view = value;
}
}
public virtual void OnException(ExceptionContext filterContext) {
if (filterContext == null) {
throw new ArgumentNullException("filterContext");
}
if (filterContext.IsChildAction) {
return;
}
// If custom errors are disabled, we need to let the normal ASP.NET exception handler
// execute so that the user can see useful debugging information.
if (filterContext.ExceptionHandled || !filterContext.HttpContext.IsCustomErrorEnabled) {
return;
}
Exception exception = filterContext.Exception;
// If this is not an HTTP 500 (for example, if somebody throws an HTTP 404 from an action method),
// ignore it.
if (new HttpException(null, exception).GetHttpCode() != 500) {
return;
}
if (!ExceptionType.IsInstanceOfType(exception)) {
return;
}
string controllerName = (string)filterContext.RouteData.Values["controller"];
string actionName = (string)filterContext.RouteData.Values["action"];
HandleErrorInfo model = new HandleErrorInfo(filterContext.Exception, controllerName, actionName);
filterContext.Result = new ViewResult {
ViewName = View,
MasterName = Master,
ViewData = new ViewDataDictionary<HandleErrorInfo>(model),
TempData = filterContext.Controller.TempData
};
filterContext.ExceptionHandled = true;
filterContext.HttpContext.Response.Clear();
filterContext.HttpContext.Response.StatusCode = 500;
// Certain versions of IIS will sometimes use their own error page when
// they detect a server error. Setting this property indicates that we
// want it to try to render ASP.NET MVC's error page instead.
filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;
}
}
源代码包含注释,并且不仅仅是自我解释。它检查的第一件事是您是否在web.config中启用了自定义错误(即<customErrors mode="On">
)。如果没有,它什么也不做=> YSOD。如果启用了自定义错误,则它将呈现“错误”视图,并向其传递一个包含异常堆栈跟踪和其他有用信息的模型。