blocks|key|1522173|text|我猜，您可能希望存储所有线程，而不是让一个变量tThread来存储线程，所以应该有一个线程的List。所以就像这样：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1522174|Sub
++++Dim+threads+as+New+List(Of+Thread)
++++For+Each+lvItem+As+ListViewItem+In+_ListView.SelectedItems
++++++++tThread+=+New+Thread(AddressOf+Me.myFunction())
++++++++tThread+.Start()
++++++++threads.Add(tThread)
++++Next
End+Sub|code-block|syntax|javascript|1522175|否则，如果有其他问题，请提供更多详细信息。|1522176|entityMap^0|N|7|1A|4|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|N|$]]

I'm guessing that instead of having one variable <code>tThread</code> storing the thread, you probably meant to store all the threads, so instead have a <code>List</code> of them. So something like:

<pre><code>Sub
 Dim threads as New List(Of Thread)
 For Each lvItem As ListViewItem In _ListView.SelectedItems
 tThread = New Thread(AddressOf Me.myFunction())
 tThread .Start()
 threads.Add(tThread)
 Next
End Sub
</code></pre>

Otherwise, if there's another issue, please supply more details.

blocks|key|4005311|text|是否确实选择了这些项目？我在列表视图中尝试了以下几个项目，并按预期工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4005312|Private+Sub+Button2_Click(ByVal+sender+As+System.Object,+_
++++++++++++++++++++++++++ByVal+e+As+System.EventArgs)+Handles+Button2.Click

++++For+Each+lvItem+As+ListViewItem+In+ListView1.SelectedItems
++++++++Dim+t+As+Threading.Thread+=+New+Threading.Thread(AddressOf+myFunction)
++++++++t.Start(lvItem)
++++Next

End+Sub

Private+Sub+myFunction(ByVal+lvi+As+Object)
++++Dim+lvItem+As+ListViewItem+=+CType(lvi,+ListViewItem)
++++Debug.WriteLine(lvItem.Text)
End+Sub|code-block|syntax|javascript|4005313|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|$]]

Are you sure the items are selected? I tried the following with a few items in the listview and it worked as expected.

<pre><code>Private Sub Button2_Click(ByVal sender As System.Object, _
 ByVal e As System.EventArgs) Handles Button2.Click

 For Each lvItem As ListViewItem In ListView1.SelectedItems
 Dim t As Threading.Thread = New Threading.Thread(AddressOf myFunction)
 t.Start(lvItem)
 Next

End Sub

Private Sub myFunction(ByVal lvi As Object)
 Dim lvItem As ListViewItem = CType(lvi, ListViewItem)
 Debug.WriteLine(lvItem.Text)
End Sub
</code></pre>

blocks|key|1519634|text|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1519635|我想从ListView中选择多个文件(这是文件路径)，并将它们转换为mp3文件，但使用上述解决方案。它成功地转换了第一个选定的文件，但随后停止。|blockquote|1519636|1519637|1519638|为每个文件创建单独的线程并不是最优的。在某些情况下，这实际上会导致比按顺序执行所有线程更差的性能，因为您的系统将花费太多时间在不同线程之间来回切换。相反，您希望选择少量线程，并按这些线程对您的项进行时间排队。|1519639|有很多方法可以实现这一点：|1519640|1519641|您可以编写自定义代码，使线程数基于物理处理器核心数(通常大于2或核心数-1)。这是很多额外的工作，而且容易出错。|unordered-list-item|1519642|你可以使用ThreadPool.QueueUserWorkItem()中的内置功能。这很棒，但跟踪项目进度可能会比较麻烦。|offset|length|style|CODE|1519643|您可以使用Task+Parallel+Library。这需要.Net+4，但它可能是您目前最好的选择。预先学习这些概念的额外工作也将是一个巨大的回报，听起来微软正在围绕任务概念建立.Net+5中一些更重要的功能。|1519644|1519645|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/4yd16hza.aspx|1|http://msdn.microsoft.com/en-us/library/dd460717.aspx^0|0|0|0|0|0|0|0|0|5|U|5|U|0|0|5|L|1|0|0^^$0|@$1|2|3|-4|4|5|6|16|7|@]|8|@]|9|$]]|$1|A|3|B|4|C|6|17|7|@]|8|@]|9|$]]|$1|D|3|-4|4|5|6|18|7|@]|8|@]|9|$]]|$1|E|3|-4|4|5|6|19|7|@]|8|@]|9|$]]|$1|F|3|G|4|5|6|1A|7|@]|8|@]|9|$]]|$1|H|3|I|4|5|6|1B|7|@]|8|@]|9|$]]|$1|J|3|-4|4|5|6|1C|7|@]|8|@]|9|$]]|$1|K|3|L|4|M|6|1D|7|@]|8|@]|9|$]]|$1|N|3|O|4|M|6|1E|7|@$P|1F|Q|1G|R|S]]|8|@$P|1H|Q|1I|1|1J]]|9|$]]|$1|T|3|U|4|M|6|1K|7|@]|8|@$P|1L|Q|1M|1|1N]]|9|$]]|$1|V|3|-4|4|5|6|1O|7|@]|8|@]|9|$]]|$1|W|3|-4|4|5|6|1P|7|@]|8|@]|9|$]]]|X|$Y|$4|Z|10|11|9|$12|13]]|14|$4|Z|10|11|9|$12|15]]]]

<blockquote>
 I want to select multiple files (which are file paths) from ListView and convert them in mp3 files but with above solution. it converts first selected file successfully but then stops.
</blockquote>

Creating a separate thread for each file is sub-optimal. In some cases, this can actually result in worse performance than doing them all sequentially, because your system will spend too much time switching back and forth between different threads. Instead, you want to choose a small number of threads and queue your items for time by those threads. 

There are a lot of ways to implement this: 

<ul>
<li>You can write custom code that bases the number of threads on the number of physical processor cores (greater of 2 or the number of cores - 1 is common). This is a lot of extra work, and is error prone.</li>
<li>You can use the built-in in <a href="http://msdn.microsoft.com/en-us/library/4yd16hza.aspx" rel="nofollow"><code>ThreadPool.QueueUserWorkItem()</code></a>. This is great, but it can be tricky to track progress of your items.</li>
<li>You can use the <a href="http://msdn.microsoft.com/en-us/library/dd460717.aspx" rel="nofollow">Task Parallel Library</a>. This requires .Net 4, but it's probably your best option by far. The extra work upfront learning the concepts will also be a huge payoff, and it sounds like Microsoft is basing some of the more important features in .Net 5 around the Task concept.</li>
</ul>

Is there a way to start same Thread form <code>foreach</code> loop

<pre><code>Sub
For Each lvItem As ListViewItem In _ListView.SelectedItems
 tThread = New Thread(AddressOf Me.myFunction())
 tThread .Start()
Next
End Sub


Sub myFunction()
//Code
End Sub
</code></pre>

In my case, when i select one item from list it is working fine...but when i select more than one files it odes not work.

Starting same thread from a foreach loop not working

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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有没有办法启动相同线程形式的foreach循环？SubFor Each lvItem As ListViewItem In _ListView.SelectedItems    tThread = New Thread(AddressOf Me.myFunction())    tThread .Start()Next...

问从foreach循环启动同一线程不起作用
EN

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问从foreach循环启动同一线程不起作用EN