c# – AggregateException.Flatten()丢失堆栈跟踪信息.丢失的信息是否重要？

AggregateException.Flatten方法的文档 on MSDN说明如下：“如果任何内部异常本身是AggregateException的实例,则此方法将以递归方式展平所有这些异常.新AggregateException中返回的内部异常将是所有内部异常的并集.来自异常树的内部异常,以提供的AggregateException实例为根.“

这听起来很可疑,就像我们将丢失堆栈跟踪信息一样,所以我看一下实现on Reference Source,看起来堆栈跟踪信息确实会丢失.

所以我们进行了测试：

try
{
    try
    {
        try
        {
            throw new InvalidOperationException();
        }
        catch (Exception e)
        {
            try
            {
                throw new FormatException();
            }
            catch (Exception e2)
            {
                throw new AggregateException(e,e2);
            }
        }
    }
    catch (Exception e)
    {
        try
        {
            throw new NotImplementedException();
        }
        catch (Exception e2)
        {
            throw new AggregateException(e,e2);
        }
    }
}
catch (Exception e)
{
    File.AppendAllText(@"C:\tmp.txt",e.ToString());
    File.AppendAllText(@"C:\tmp.txt",((AggregateException)e).Flatten().ToString());
}

测试结果如下：

System.AggregateException: One or more errors occurred. ---> System.AggregateException: One or more errors occurred. ---> system.invalidOperationException: Operation is not valid due to the current state of the object.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 29
   --- End of inner exception stack trace ---
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 39
   --- End of inner exception stack trace ---
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 51
---> (Inner Exception #0) System.AggregateException: One or more errors occurred. ---> system.invalidOperationException: Operation is not valid due to the current state of the object.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 29
   --- End of inner exception stack trace ---
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 39
---> (Inner Exception #0) system.invalidOperationException: Operation is not valid due to the current state of the object.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 29<---

---> (Inner Exception #1) System.FormatException: One of the identified items was in an invalid format.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 35<---
<---

---> (Inner Exception #1) System.NotImplementedException: The method or operation is not implemented.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 47<---
System.AggregateException: One or more errors occurred. ---> System.NotImplementedException: The method or operation is not implemented.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 47
   --- End of inner exception stack trace ---
---> (Inner Exception #0) System.NotImplementedException: The method or operation is not implemented.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 47<---

---> (Inner Exception #1) system.invalidOperationException: Operation is not valid due to the current state of the object.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 29<---

---> (Inner Exception #2) System.FormatException: One of the identified items was in an invalid format.
   at ConsoleApplication6.Program.Main(String[] args) in C:\Projects\ConsoleApplication6\ConsoleApplication6\Program.cs:line 35<---

请注意,在展平的AggregateException中没有提到第39行！

丢失的信息是否重要？或者有没有理由认为,当我们压平AggregateException时,我们会丢失第39行？

解决方法

如果我正确理解了您的示例,那么您将说丢失了抛出AggregateException时创建的堆栈跟踪.这是预期的,因为Flatten()将过滤掉属于InnerExceptions层次结构的任何AggregateExceptions.我不会说信息丢失,因为在大多数情况下,有用的信息将在非AggregateException实例中.