blocks|key|1523297|text|如果在finalization上下文中调用Dispose()并抛出异常，您的进程将被终止。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1523298|如果您怀疑Foo.Dispose()抛出了一个异常，我会尽可能最后处理它，并将它包装在try/catch中。尽你所能在catch中摆脱它--将reference设置为null。从Dispose()抛出异常是非常糟糕的，应该避免。|1523299|不幸的是，如果这是有bet的第三方代码，你最好的办法就是让他们来修复它。你不应该在它之后手动清理它。|1523300|希望这能有所帮助。|1523301|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

If Dispose() is called inside of a finalization context and it throws an exception, your process will be terminated.

If you suspect that Foo.Dispose() is throwing an exception, I would dispose of it last if possible, and wrap it in try/catch. Do everything you can to get rid of it in the catch - set the reference to null. It is very bad to throw exceptions from Dispose() and should be avoided.

Unfortunately, if this is buggy third-party code, your best bet would be to get them to fix it. You shouldn't have to manually clean up after it.

Hope that helps.

blocks|key|1308325|text|因为你不必在using()语句中分配变量--为什么不使用'stacked‘using语句呢？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1308326|void+Dispose()
{
++++//+the+example+in+the+question+didn't+use+the+full+protected+Dispose(bool)+pattern
++++//+but+most+code+should+have+if+(!disposed)+{+if+(disposing)+{+...

++++using+(m_foo)
++++using+(m_bar)++
++++{
++++++++//+no+work,+using+statements+will+check+null+
++++++++//+and+call+Dispose()+on+each+object
++++}

++++m_bar+=+null;
++++m_foo+=+null;
}|code-block|syntax|javascript|1308327|“堆叠”using语句的扩展如下：|1308328|using+(m_foo)
{
++++using+(m_bar)+{+/*+do+nothing+but+call+Dispose+*/+}
}|1308329|因此Dispose()调用被放在单独的finally块中：|1308330|try+{
++++try+{+//+do+nothing+but+call+Dispose
++++}
++++finally+{+
++++++++if+(m_bar+!=+null)
++++++++++++m_bar.Dispose();+
++++}
finally+{+
++++if+(m_foo+!=+null)
++++++++m_foo.Dispose();
}|1308331|我很难在一个地方找到这方面的参考资料。“堆叠的”using语句可以在old+Joe+Duffy+blog+post中找到(参见“C#和VB+Using语句，C%2B%2B堆栈语义”一节)。IDisposable上的许多StackOverflow+answers都引用了Joe+Duffy的帖子。我还发现了一个recent+question，其中使用局部变量语句进行堆叠似乎很常见。除了C#+language+spec之外，我找不到finally块的链接(+C#+3.0规范中的8.13节)，并且只能在一个'using‘块中找到多个变量，这并不是我所建议的，但是如果你破坏IL，你会发现try/finally块是嵌套的。在null检查中，同样来自C#规范：“如果获取了null资源，则不会调用Dispose，也不会抛出任何异常。”|offset|length|1308332|entityMap|0|LINK|mutability|MUTABLE|url|http://www.bluebytesoftware.com/blog/PermaLink.aspx?guid=88e62cdf-5919-4ac7-bc33-20c06ae539ae|1|https://stackoverflow.com/questions/1329739/nested-using-statements-in-c|2|http://go.microsoft.com/fwlink/?LinkId=64165^0|0|0|0|0|0|0|Y|N|0|46|F|1|58|G|2|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|15|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|16|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|17|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|18|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|19|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|1A|8|@]|9|@$Q|1B|R|1C|1|1D]|$Q|1E|R|1F|1|1G]|$Q|1H|R|1I|1|1J]]|A|$]]|$1|S|3|-4|5|6|7|1K|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z]]|10|$5|V|W|X|A|$Y|11]]|12|$5|V|W|X|A|$Y|13]]]]

Because you don't have to allocate the variables in a using() statement - why not use 'stacked' using statements for this?

<pre><code>void Dispose()
{
 // the example in the question didn't use the full protected Dispose(bool) pattern
 // but most code should have if (!disposed) { if (disposing) { ...

 using (m_foo)
 using (m_bar) 
 {
 // no work, using statements will check null 
 // and call Dispose() on each object
 }

 m_bar = null;
 m_foo = null;
}
</code></pre>

The 'stacked' using statements are expanded like this:

<pre><code>using (m_foo)
{
 using (m_bar) { /* do nothing but call Dispose */ }
}
</code></pre>

So the Dispose() calls are put in seperate finally blocks:

<pre><code>try {
 try { // do nothing but call Dispose
 }
 finally { 
 if (m_bar != null)
 m_bar.Dispose(); 
 }
finally { 
 if (m_foo != null)
 m_foo.Dispose();
}
</code></pre>

I had a hard time finding a reference for this in one place. The 'stacked' using statements are found in an <a href="http://www.bluebytesoftware.com/blog/PermaLink.aspx?guid=88e62cdf-5919-4ac7-bc33-20c06ae539ae" rel="nofollow noreferrer">old Joe Duffy blog post</a> (see section 'C# and VB Using Statement, C++ Stack Semantics'). The Joe Duffy post is referenced by many StackOverflow answers on IDisposable. I also found a <a href="https://stackoverflow.com/questions/1329739/nested-using-statements-in-c">recent question</a> where stacked using statements for local variables appear to be common. I couldn't find the chaining of finally blocks anywhere but the <a href="http://go.microsoft.com/fwlink/?LinkId=64165" rel="nofollow noreferrer">C# language spec</a> (section 8.13 in C# 3.0 spec), and only for multiple varaibles within a single 'using' block, which isn't exactly what I'm proposing, but if you disasemble the IL you'll find the try/finally blocks are nested. On the null check, also from the C# spec: 'If a null resource is acquired, then no call to Dispose is made, and no exception is thrown.'

blocks|key|1308366|text|在我的例子中，这是因为一个线程在关闭窗体时访问UI元素。我通过中止form+close上的线程重新解决了这个问题。("FormClosing“事件)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1308367|FormClosing+%2B=+(o,+e)+=>+worker.Abort();|code-block|syntax|javascript|1308368|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

In my case it was because of a thread accessing UI element while closing the form. I resovled it by aborting the thread on form close. ("FormClosing" event)

<pre><code>FormClosing += (o, e) =&gt; worker.Abort();
</code></pre>

Recently, I was researching some tricky bugs about object not disposed.

I found some pattern in code. It is reported that some m_foo is not disposed, while it seems all instances of SomeClass has been disposed.

<pre><code>public class SomeClass: IDisposable
{
 void Dispose()
 {
 if (m_foo != null)
 {
 m_foo.Dispose();
 }
 if (m_bar != null)
 {
 m_bar.Dispose();
 } 
 }

 private Foo m_foo;

 private Bar m_bar;

}
</code></pre>

I suspects that Foo.Dispose might throw a exception, so that following code is not executed so m_bar is not disposed. 

Since Foo/Bar might be from third party, so it is not guaranteed to not throwing exception. 

If just wrap all Dispose invocation with try-catch, the code will turn to be clumsy.

What's best practice to handle this?

How to handle exception thrown from Dispose?

最近，我在研究一些关于object not disposed的棘手bug。我在代码中发现了一些模式。据报道，一些m_foo没有被释放，而SomeClass的所有实例似乎都已经被释放了。public class SomeClass: IDisposable{    void Dispose()    {       if...

问如何处理Dispose抛出的异常？
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