我读过StackOverflow上十几个类似的问题,但我似乎无法把握这一点。 至于在web.config和HandleErrorAttribute自定义错误节点,请问Error.cshtml曾经得到的叫什么? 最终,这个问题的答案可能是答案的那些几个问题已经在那里关于ASP.NET MVC的错误处理一个。 但是,事情的事实是,我不知道是哪一个。
Answer 1:
Inside your Global.asax you have the following method:
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new HandleErrorAttribute());
}
This registers the HandleErrorAttribute as global action filter. This means that this handler is automatically applied to all controller actions. Now let's take a look at how this attribute is implemented by looking at the source code:
[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;
}
}
The source code contains comments and is more than self explanatory. The first thing it checks is whether you have enabled custom errors in your web.config (i.e. <customErrors mode="On">
). If you haven't it does nothing => YSOD. If you have enabled custom errors then it renders the Error view passing it a model containing the exception stacktrace and other useful information.
文章来源: How is Error.cshtml called in ASP.NET MVC?
标签:
asp.net-mvc-3