我要实现自定义的异常处理在我的图书馆，让我知道发生了异常的地方，所以我这样做：

I want to implement custom exception handling in my library so that I know where an exception occurred, so I am doing this:

try
{
    DoSomething();
}
catch(Exception ex)
{
    //LibraryException refers to any exception in the libraries exception hierarchy
    throw new LibraryException(ex.Message, ex);
}

这应该避免？

Should this be avoided?

是否有任何性能影响？

什么是醒目的影响，嵌套和重新抛出异常？

What are the implications of catching, nesting and re-throwing exceptions?

推荐答案

唯一潜在的问题是，你赶上一个非特异性异常，所以不符合在异常处理准则。

The only potential problem is that you're catching a non-specific Exception, so not conforming to the exception handling guidelines.

以下情况之一会比较一致这些准则：

One of the following would be more conformant with these guidelines:

try
{
    DoSomething();
}
catch(SomeException ex)
{
    throw new LibraryException(ex.Message, ex);
}

或

try
{
    DoSomething();
}
catch(Exception ex)
{
    if (ex is SomeException || ex is SomeOtherException)
    {
        throw new LibraryException(ex.Message, ex);
    }
    throw;
}

至于性能，一旦异常被抛出，一些特殊情况发生，你可能不关心它包裹的小额外的开销。

As for performance, once an Exception has been thrown, something exceptional has happened, and you probably don't care about the small additional overhead of wrapping it.

从评论：

在大多数情况下，当一个库选择来包装异常将包被的库的范围，...

in most cases when a library chooses to wrap exceptions it will wrap all exceptions that are thrown outside of the scope of the library, ...

我不同意这一点，虽然这是无可否认的主观。库的一个例子，它包装的例外是的SqlMembershipProvider ，它封装了一些具体的例外在 ProviderException ，例如：

I disagree with this, though it's admittedly subjective. One example of a library that wraps exceptions is SqlMembershipProvider, which wraps some specific exceptions in a ProviderException, e.g.:

try
{
    new Regex(this._PasswordStrengthRegularExpression);
}
catch (ArgumentException exception)
{
    throw new ProviderException(exception.Message, exception);
}

但其他例外，如 SQLEXCEPTION ，一个来电，不能指望处理传播展开。

but other exceptions such as SqlException that a caller can't be expected to handle are propagated unwrapped.