MVC源码分析 - Error过滤器

<system.web>
  <!--mode : Off / On / RemoteOnly-->
  <customErrors mode="RemoteOnly">
    <error statusCode="404" redirect="~/NotFound/Index"/>
  </customErrors>
</system.web>

[HandleError(ExceptionType = typeof(Exception), View = "Error500", Master = "_Layout1")]
public ActionResult Index()
{
    throw new Exception("Home/Index 主动抛出的异常");
}

public ActionResult Index()
{
    throw new Exception("Home/Index 主动抛出的异常");
}

protected override void OnException(ExceptionContext filterContext)
{
    filterContext.HttpContext.Response.Redirect("~/Errors/MyError?msg=" + filterContext.Exception.Message);
}

public ActionResult MyError(string msg)
{
    ViewBag.Msg = msg;
    return View();
}

public class MyErrorsAttribute : HandleErrorAttribute
{
    public override void OnException(ExceptionContext filterContext)
    {
        base.OnException(filterContext);
        //标记此错误已经处理过, 如果别的错误捕捉器捕捉到此错误, 就不会重复处理了.
        filterContext.ExceptionHandled = true;
        filterContext.HttpContext.Response.Redirect("~/Errors/MyError?msg=" + filterContext.Exception.Message);
    }
}

public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new MyErrorsAttribute());
    }
}

[MyErrors]
public ActionResult Index()
{
    throw new Exception("Foot/Index 主动抛出的异常");
}