如何在ASP.NET MVC中调用Error.cshtml？

我已经阅读了StackOverflow上的十几个类似的问题，但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，Error.cshtml是如何被调用的？ 最终，这个问题的答案可能是对ASP.NET MVCerror handling已经存在的几个问题之一的答案。 但事实是，我不知道是哪一个。

Answer 1

在你的Global.asax里面有以下方法：

public static void RegisterGlobalFilters(GlobalFilterCollection filters) { filters.Add(new HandleErrorAttribute()); } 

这将HandleErrorAttribute注册为全局操作filter。 这意味着这个处理程序会自动应用于所有的控制器动作。 现在我们来看看如何通过查看源代码来实现这个属性：

 [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，而不是自我解释。 它检查的第一件事是你是否已经在你的web.config中启用了自定义错误（即<customErrors mode="On"> ）。 如果你没有，它什么都不做=> YSOD。 如果您启用了自定义错误，那么它会呈现错误视图，向其传递一个包含exception堆栈跟踪和其他有用信息的模型。