blocks|key|4476806|text|Any只确定是否存在匹配，它不返回除bool之外的任何内容，并且需要执行查询。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4476807|您可以使用Where或First/FirstOrDefault|4476808|string+firstMastch+=+FilePrefixList.FirstOrDefault(s+=>+FileName.StartsWith(s));+//+null+if+no+match

var+allMatches+=+FilePrefixList.Where(s+=>+FileName.StartsWith(s));
string+firstMastch+=+allMatches.FirstOrDefault();+//+null+if+no+match|code-block|syntax|javascript|4476809|所以如果你只需要知道是否匹配就可以使用Any，否则你可以使用FirstOrDefault来获取第一个匹配或null(对于引用类型)。|4476810|由于Any需要执行查询，因此效率较低：|4476811|string+firstMatch+=+null;
if(FilePrefixList.Any(s+=>+FileName.StartsWith(s)))
{
++++//+second+execution
++++firstMatch+=+FilePrefixList.First(s+=>+FileName.StartsWith(s));
}|4476812|如果您想将所有匹配项放入一个单独的集合中，如List<string>|4476813|List<string>+matchList+=+allMatches.ToList();+//+or+ToArray()|4476814|如果您想输出所有匹配项，可以使用String.Join|4476815|string+matchingFiles+=+String.Join(",",+allMatches);++|4476816|entityMap^0|0|3|I|4|0|5|5|B|5|H|E|0|0|J|3|U|E|1H|4|0|2|3|0|0|M|C|0|0|G|B|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|1E|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1F|8|@$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]]|D|@]|E|$]]|$1|O|3|P|5|6|7|1M|8|@$9|1N|A|1O|B|C]]|D|@]|E|$]]|$1|Q|3|R|5|J|7|1P|8|@]|D|@]|E|$K|L]]|$1|S|3|T|5|6|7|1Q|8|@$9|1R|A|1S|B|C]]|D|@]|E|$]]|$1|U|3|V|5|J|7|1T|8|@]|D|@]|E|$K|L]]|$1|W|3|X|5|6|7|1U|8|@$9|1V|A|1W|B|C]]|D|@]|E|$]]|$1|Y|3|Z|5|J|7|1X|8|@]|D|@]|E|$K|L]]|$1|10|3|-4|5|6|7|1Y|8|@]|D|@]|E|$]]]|11|$]]

<code>Any</code> determines only if there is a match, it doesn't return anything apart from the <code>bool</code> and it needs to execute the query.

You can use <code>Where</code> or <code>First</code>/<code>FirstOrDefault</code>:

<pre><code>string firstMastch = FilePrefixList.FirstOrDefault(s =&gt; FileName.StartsWith(s)); // null if no match

var allMatches = FilePrefixList.Where(s =&gt; FileName.StartsWith(s));
string firstMastch = allMatches.FirstOrDefault(); // null if no match
</code></pre>

So <code>Any</code> is fine if all you need to know is if ther's a match, otherwise you can use <code>FirstOrDefault</code> to get the first match or <code>null</code>(in case of reference types).

Since <code>Any</code> needs to execute the query this is less efficient:

<pre><code>string firstMatch = null;
if(FilePrefixList.Any(s =&gt; FileName.StartsWith(s)))
{
 // second execution
 firstMatch = FilePrefixList.First(s =&gt; FileName.StartsWith(s));
}
</code></pre>

If you want to put all matches into a separate collection like a <code>List&lt;string&gt;</code>:

<pre><code>List&lt;string&gt; matchList = allMatches.ToList(); // or ToArray()
</code></pre>

If you want to output all matches you can use <code>String.Join</code>:

<pre><code>string matchingFiles = String.Join(",", allMatches); 
</code></pre>

blocks|key|4476863|text|请检查尝试这个:我们假设FilePrefixList是集合列表|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4476864|+class+A
++++++++{
++++++++++++public+int+ID+{+get;+set;+}
++++++++++++public+string+Name+{+get;+set;+}
++++++++}

+List<A>+FilePrefixList=+new++List<A>();
+++++++++++++FilePrefixList.Add(new+A
++++++++++++{
++++++++++++++++ID+=+1,
++++++++++++++++Name+=+"One"
++++++++++++});
++++++++++++FilePrefixList.Add(new+A
++++++++++++{
++++++++++++++++ID+=2,
++++++++++++++++Name+=+"Two"
++++++++++++});
++++++++++++FilePrefixList.Add(new+A
++++++++++++{
++++++++++++++++ID+=+3,
++++++++++++++++Name+=+"Three"
++++++++++++});|code-block|syntax|javascript|4476865|从列表中选择数据为：|4476866|var+listItems+=+FilePrefixList.Where(x+=>x.Name.StartsWith("T")).ToList();|4476867|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

please check try this:
we assuming FilePrefixList is collectionlist

<pre><code> class A
 {
 public int ID { get; set; }
 public string Name { get; set; }
 }

 List&lt;A&gt; FilePrefixList= new List&lt;A&gt;();
 FilePrefixList.Add(new A
 {
 ID = 1,
 Name = "One"
 });
 FilePrefixList.Add(new A
 {
 ID =2,
 Name = "Two"
 });
 FilePrefixList.Add(new A
 {
 ID = 3,
 Name = "Three"
 });
</code></pre>

select data from list is:

<pre><code>var listItems = FilePrefixList.Where(x =&gt;x.Name.StartsWith("T")).ToList();
</code></pre>

<pre><code>FilePrefixList.Any(s =&gt; FileName.StartsWith(s))
</code></pre>

Can I get <code>s</code> value here? I want to display the matched string.

List.Any get matched String

FilePrefixList.Any(s => FileName.StartsWith(s))我可以在这里获取s值吗？我想显示匹配的字符串。

问List.Any获取匹配字符串
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