问题描述
找不到MSDN文档中的任何这一点。
Can't find anything in the MSDN documentation on this.
即。是它足够的做，说：
I.e. is it enough to do, say:
using(PrincipalSearcher searcher = ...)
{
foreach (var principal in searcher.FindAll())
{
... do something ...
} // The PrincipalSearchResult<T> returned by searcher.FindAll is disposed here
}
这是我见过做最例子，或者我应该做的：
which is what most examples I've seen do, or should I do:
using(PrincipalSearcher searcher = ...)
{
foreach(var principal in searcher.FindAll())
{
using (principal)
{
// ... do something ...
}
}
}
后者（显式地处理迭代中的每个项目）看起来更安全 - 即符合指引，明确处理所有IDisposable的对象 - 但它是一个有点乱;例如，precludes使用LINQ的迭代搜索结果。
The latter (explicitly disposing each item during iteration) looks "safer" - i.e. conforms to the guideline to explicitly dispose all IDisposable objects - but it's a bit messy; for example, it precludes the use of LINQ to iterate over search results.
在回应@ RUP的评论：
In response to @Rup's comment:
您可以编写返回一个结果从父迭代器
是的，我认为这工作，使LINQ。类似下面的扩展方法：
Yes, I think that would work to enable LINQ. Something like the following extension method:
public static IEnumerable<T> EnumerateAndDispose<T>(this IEnumerable<T> collection) where T : IDisposable
{
foreach (T item in collection)
{
using (item)
{
yield return item;
}
}
}
可以使用的为：
which can be used as:
searcher.FindAll().EnumerateAndDispose().Select(... use LINQ ...)
不过，有必要吗？
But is it necessary?
推荐答案
一般speacking，在很多情况下，不调用Dispose（）不会造成大问题：写得好处置的对象将实施清理东西的必要了同样的逻辑终结。（免责声明：我不是说不叫处理：！这是有原因的。例如，最终确定可能发生了很多后来我只说明什么后果这里）
Generally speacking, in many cases, not calling Dispose() will not cause big problems: well written disposable objects will implement the same logic needed to clean things up in the finalizer. (Disclaimer: I'm not saying "do not call dispose": it is there for a reason! For example, Finalization can happen a lot later. I'm only describing what are the consequences here).
不过，AD对象是一个明显的例外;尤其是， SearchResultCollection 是众所周知的，从这个问题的痛苦（参考：MSDN（既类文档及其他物品），和<一href="http://books.google.it/books?id=exlzxcsE-7QC&lpg=PA696&ots=JE-bIYLmG-&dq=SearchResultCollection%20dispose&hl=it&pg=PA696#v=onepage&q=SearchResultCollection%20dispose&f=false">Active目录：设计，部署和运行Active Directory ）。看来，由于技术原因，不可能以释放资源在其终结，所以不调用dispose将导致内存泄漏。
However, AD objects are a notable exception; in particular, SearchResultCollection is known for suffering from this problem (references: MSDN (both the class docs and other articles), and Active Directory: Designing, Deploying, and Running Active Directory). It seems that for technical reasons it is not possible to release resources in its finalizer, so not calling dispose will lead to memory leaks.
正如斯科特和乔，很多MSDN的例子并不调用Dispose集合中的物品;然而，瑞安邓恩，前Windows Azure的技术专家与人合着的的.NET开发人员指南目录服务编程的，建议使用来调用的。从帖子：
As pointed out by Scott and Joe, many MSDN examples do not call dispose on the items in the collection; however, Ryan Dunn, former Windows Azure Technical Evangelist and co-author of the The .NET Developers Guide to Directory Services Programming, recommends to use to call dispose on each item in this blog post. From the post:
在一般情况下，始终明确以下对象类型调用Dispose（）：
- 的DirectoryEntry
- SearchResultCollection（从.FindAll（））
- 在DirectorySearcher从（如果您没有明确设置一个SearchRoot）
- DirectoryEntry
- SearchResultCollection (from .FindAll())
- DirectorySearcher (if you have not explicitly set a SearchRoot)
这是你可以有一个权威人士最近，我相信; 然而的我个人的意见是：
This is the closest you can have to an "authoritative source", I believe; however my personal opinion is:
- 如果可以的话，就调用dispose。它不会做任何不好的，特别是如果你能找回LINQ功能与乔的扩展方法
- 去使用反射/ ilspy /反汇编和/或如 dotTrace 的内存配置文件，真正看到是怎么回事（基本上，斯科特已经做了，但不断深入）
- if you can, do call dispose. It will not make any bad, especially if you can get back LINQ functionality with Joe's extension method
- go and use reflector/ilspy/ildasm AND/OR a memory profile like dotTrace to really see what is going on (basically, what Scott already did, but going deeper)
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