blocks|key|73182|text|是否可以通过某些键来识别每一项？如果是这样，那么您可以从键到项保存一个字典，当从服务器获得更新的列表时，您可以查找字典中的每个键并删除/更新相应的项。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|73183|若要从列表中删除项，可以将整个服务器数据复制到另一个字典中，并查阅本地列表的每个项。|73184|这个解决方案的复杂性是O(n)，而不是在列表上使用Except，后者是O(n%5E2)。|offset|length|style|CODE|73185|entityMap^0|0|0|P|6|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|N|8|@$F|O|G|P|H|I]]|9|@]|A|$]]|$1|J|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|K|$]]

Is it possible to identify each item by some key? If so, then you can hold a dictionary from key to item, and when you get the updated list from the server, you can look for each key in the dictionary and remove/update the corresponding item. 

To enable deletion of items from the list, you can copy the entire server data into another dictionary and consult it for each item of the local list.

The complexity of this solution is O(n), as opposed to using <code>Except</code> on lists, which would be O(n^2).

blocks|key|73187|text|如果通知包含整个远程列表，则可以使用Linq的Except|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|73188|List<int>+localList+=+new+List<int>()+{1,+2,+3};
List<int>+remoteList+=+new+List<int>()+{1,+2,+4};

var+addedItems+=+remoteList.Except(localList);
var+removedItems+=+localList.Except(remoteList);|code-block|syntax|javascript|73189|entityMap^0|N|6|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

If the notification consists of the whole remote list, you can use Linq's <code>Except</code>:

<pre><code>List&lt;int&gt; localList = new List&lt;int&gt;() {1, 2, 3};
List&lt;int&gt; remoteList = new List&lt;int&gt;() {1, 2, 4};

var addedItems = remoteList.Except(localList);
var removedItems = localList.Except(remoteList);
</code></pre>

blocks|key|2588308|text|这可以用LINQ来完成|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2588309|++++string[]+names1+=+System.IO.File.ReadAllLines(@"../../../names1.txt");
++++string[]+names2+=+System.IO.File.ReadAllLines(@"../../../names2.txt");

++++//+Create+the+query.+Note+that+method+syntax+must+be+used+here.
++++IEnumerable<string>+differenceQuery+=
++++++names1.Except(names2);

++++//+Execute+the+query.
++++Console.WriteLine("The+following+lines+are+in+names1.txt+but+not+names2.txt");
++++foreach+(string+s+in+differenceQuery)
++++++++Console.WriteLine(s);|code-block|syntax|javascript|2588310|entityMap^0|4|4|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

it could be done with <code>LINQ</code>

<pre><code> string[] names1 = System.IO.File.ReadAllLines(@"../../../names1.txt");
 string[] names2 = System.IO.File.ReadAllLines(@"../../../names2.txt");

 // Create the query. Note that method syntax must be used here.
 IEnumerable&lt;string&gt; differenceQuery =
 names1.Except(names2);

 // Execute the query.
 Console.WriteLine("The following lines are in names1.txt but not names2.txt");
 foreach (string s in differenceQuery)
 Console.WriteLine(s);
</code></pre>

I have a local copy of <code>System.Collections.Generic.List</code> which is populated by a server list of the same type. When the server list is changed (an item added to list or removed from list), my application gets a notification. 

In response to that notification, I want to update my local copy of the list. I dont want to clear the local copy and replace it entirely with the server copy. I want to find the difference and delete the ones that are deleted and add the ones that are added.

What's the best technique to do that?

Find difference in items of two System.Collections.Generic.Lists

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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我有一个System.Collections.Generic.List的本地副本，该副本由相同类型的服务器列表填充。当服务器列表被更改(添加到列表中的项或从列表中删除的项)时，我的应用程序将收到通知。作为对该通知的回应，我希望更新列表的本地副本。我不想清除本地副本，并将其完全替换为服务器副本。我想找出不同之处，删除被删...

问查找两个System.Collections.Generic.Lists的项的差异
EN

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问查找两个System.Collections.Generic.Lists的项的差异EN