C#（五十八）之C#List

前几天，看同事写的代码中有list相关的字眼，百度了一下，原来是C#中list泛型集合。

了解一下。

List：泛型集合，List<T>类是 ArrayList 类的泛型等效类。该类使用大小可按需动态增加的数组实现 IList<T> 泛型接口。

泛型的好处：它为使用c#语言编写面向对象程序增加了极大的效力和灵活性。不会强行对值类型进行装箱和拆箱，或对引用类型进行向下强制类型转换，所以性能得到提高。

使用命名空间：

<span style="background-color:#282c34"><span style="color:#abb2bf"><span style="color:#f92672">using</span> <span style="color:#f92672">System</span>.Collections.Generic;</span></span>

list一些方法和属性：

1. Capacity 用于获取或设置List可容纳元素的数量。当数量超过容量时，这个值会自动增长。您可以设置这个值以减少容量，也可以调用trin()方法来减少容量以适合实际的元素数目。

2. Count 属性，用于获取数组中当前元素数量

3. Item( ) 通过指定索引获取或设置元素。对于List类来说，它是一个索引器。

4. Add( ) 在List中添加一个对象的公有方法

5. AddRange( ) 公有方法，在List尾部添加实现了ICollection接口的多个元素

6. BinarySearch( ) 重载的公有方法，用于在排序的List内使用二分查找来定位指定元素.

7. Clear( ) 在List内移除所有元素

8. Contains( ) 测试一个元素是否在List内

9. CopyTo( ) 重载的公有方法，把一个List拷贝到一维数组内

10. Exists( ) 测试一个元素是否在List内

11. Find( ) 查找并返回List内的出现的第一个匹配元素

12. FindAll( ) 查找并返回List内的所有匹配元素

13. GetEnumerator( ) 重载的公有方法，返回一个用于迭代List的枚举器

14. Getrange( ) 拷贝指定范围的元素到新的List内

15. IndexOf( ) 重载的公有方法，查找并返回每一个匹配元素的索引

16. Insert( ) 在List内插入一个元素

17. InsertRange( ) 在List内插入一组元素

18. LastIndexOf( ) 重载的公有方法，，查找并返回最后一个匹配元素的索引

19. Remove( ) 移除与指定元素匹配的第一个元素

20. RemoveAt( ) 移除指定索引的元素

21. RemoveRange( ) 移除指定范围的元素

22. Reverse( ) 反转List内元素的顺序

23. Sort( ) 对List内的元素进行排序

24. ToArray( ) 把List内的元素拷贝到一个新的数组内

25. trimToSize( ) 将容量设置为List中元素的实际数目

1：声明list

①、List<T> mList = new List<T>();
T为列表中元素类型，现在以string类型作为例子

<span style="background-color:#282c34"><span style="color:#abb2bf">List<<span style="color:#e6c07b">string</span>> mList = <span style="color:#f92672">new</span> List<<span style="color:#e6c07b">string</span>>();</span></span>

②、List<T> testList =new List<T> (IEnumerable<T> collection);

以一个集合作为参数创建List：

<span style="background-color:#282c34"><span style="color:#abb2bf"><span style="color:#e6c07b">string</span>[] arr = { <span style="color:#98c379">"Ha"</span>, <span style="color:#98c379">"Hunter"</span>, <span style="color:#98c379">"Tom"</span>, <span style="color:#98c379">"Lily"</span>, <span style="color:#98c379">"Jay"</span>, <span style="color:#98c379">"Jim"</span>, <span style="color:#98c379">"Kuku"</span>, <span style="color:#98c379">"Locu"</span> };
List<<span style="color:#e6c07b">string</span>> mList = <span style="color:#f92672">new</span> List<<span style="color:#e6c07b">string</span>>(arr);</span></span>

2：添加元素 Add

添加一个元素

语法： List. Add(T item)

<span style="background-color:#282c34"><span style="color:#abb2bf">mList.<span style="color:#e2b93d">Add(<span style="color:#9ccc65">"cmailla"</span>)</span>;
foreach (<span style="color:#e6c07b">string</span> item <span style="color:#f92672">in</span> mList)
{Console.<span style="color:#e2b93d">WriteLine(item)</span>;
}</span></span>

3：指定位置添加元素 Insert

语法： Insert(int index, T item);

<span style="background-color:#282c34"><span style="color:#abb2bf">            mList.Insert(<span style="color:#d19a66">0</span>,<span style="color:#98c379">"qwert"</span>);foreach (<span style="color:#e6c07b">string</span> <span style="color:#e6c07b">item</span> <span style="color:#f92672">in</span> mList){Console.WriteLine(<span style="color:#e6c07b">item</span>);}Console.WriteLine(<span style="color:#98c379">"
"</span>);</span></span>

4：添加元素集合 AddRange

语法： List. AddRange(IEnumerable<T> collection)

<span style="background-color:#282c34"><span style="color:#abb2bf">            <span style="color:#e6c07b">string</span>[] dfg = { <span style="color:#98c379">"hiocvhi"</span>,<span style="color:#98c379">"jioosdfhio"</span>,<span style="color:#98c379">"erw"</span>};mList.AddRange(dfg);foreach (<span style="color:#e6c07b">string</span> <span style="color:#e6c07b">item</span> <span style="color:#f92672">in</span> mList){Console.WriteLine(<span style="color:#e6c07b">item</span>);}Console.WriteLine(<span style="color:#98c379">"
"</span>);</span></span>

5：删除指定元素

语法：List. Remove(T item)

<span style="background-color:#282c34"><span style="color:#abb2bf">            mList.Remove(<span style="color:#98c379">"erw"</span>);foreach (<span style="color:#e6c07b">string</span> <span style="color:#e6c07b">item</span> <span style="color:#f92672">in</span> mList){Console.WriteLine(<span style="color:#e6c07b">item</span>);}Console.WriteLine(<span style="color:#98c379">"
"</span>);</span></span>

6：删除指定下标元素

语法：List. RemoveAt(int index);

<span style="background-color:#282c34"><span style="color:#abb2bf">            mList.RemoveAt(<span style="color:#d19a66">3</span>);foreach (<span style="color:#e6c07b">string</span> <span style="color:#e6c07b">item</span> <span style="color:#f92672">in</span> mList){Console.WriteLine(<span style="color:#e6c07b">item</span>);}Console.WriteLine(<span style="color:#98c379">"
"</span>);</span></span>

7：从下标index开始，删除count个元素

语法：List. RemoveRange(int index, int count);

<span style="background-color:#282c34"><span style="color:#abb2bf">            mList.RemoveRange(<span style="color:#d19a66">3</span>,<span style="color:#d19a66">5</span>);foreach (<span style="color:#e6c07b">string</span> <span style="color:#e6c07b">item</span> <span style="color:#f92672">in</span> mList){Console.WriteLine(<span style="color:#e6c07b">item</span>);}Console.WriteLine(<span style="color:#98c379">"
"</span>);</span></span>

8：判断某个元素是否在该List中：

语法：List. Contains(T item) 返回值为：true/false

<span style="background-color:#282c34"><span style="color:#abb2bf">            bool s = mList.Contains(<span style="color:#98c379">"Ha"</span>);Console.WriteLine(s);Console.WriteLine(<span style="color:#98c379">"</span>
<span style="color:#98c379">");</span></span></span>

9：给List里面元素排序：

语法： List. Sort () 默认是元素第一个字母按升序

<span style="background-color:#282c34"><span style="color:#abb2bf">            mList<span style="color:#d19a66">.Sort</span>();foreach (var item in mList){Console<span style="color:#d19a66">.WriteLine</span>(item);}Console<span style="color:#d19a66">.WriteLine</span>("
");</span></span>

10：给List里面元素顺序反转：

语法： List. Reverse () 可以与List. Sort ()配合使用，达到想要的效果

<span style="background-color:#282c34"><span style="color:#abb2bf">            mList<span style="color:#d19a66">.Reverse</span>();foreach (var item in mList){Console<span style="color:#d19a66">.WriteLine</span>(item);}Console<span style="color:#d19a66">.WriteLine</span>("
");</span></span>

11：List清空：

语法：List. Clear ()

<span style="background-color:#282c34"><span style="color:#abb2bf">            mList<span style="color:#d19a66">.Clear</span>();foreach (var item in mList){Console<span style="color:#d19a66">.WriteLine</span>(item);}Console<span style="color:#d19a66">.WriteLine</span>("
");</span></span>

12：ist.FindAll方法：检索与指定谓词所定义的条件相匹配的所有元素

语法：public List<T> FindAll(Predicate<T> match);

Predicate是对方法的委托，如果传递给它的对象与委托中定义的条件匹配，则该方法返回 true。当前 List 的元素被逐个传递给Predicate委托，并在 List 中向前移动，从第一个元素开始，到最后一个元素结束。当找到匹配项时处理即停止。

Predicate 可以委托给一个函数或者一个拉姆达表达式:

正常委托：

<span style="background-color:#282c34"><span style="color:#abb2bf">        List<<span style="color:#e6c07b">string</span>> subList = mList.FindAll(ListFind); <span style="color:#b18eb1"><em>//委托给ListFind函数</em></span><span style="color:#b18eb1"><em>//ListFind函数</em></span><span style="color:#61aeee"><span style="color:#f92672">public</span> <span style="color:#f92672">static</span> <span style="color:#e6c07b">bool</span> <span style="color:#61aeee">ListFind</span>(<span style="color:#a6e22e"><span style="color:#e6c07b">string</span> name</span>)</span>{Console.WriteLine(name);<span style="color:#f92672">if</span> (name.Length > <span style="color:#d19a66">3</span>){<span style="color:#f92672">return</span> <span style="color:#56b6c2">true</span>;}<span style="color:#f92672">return</span> <span style="color:#56b6c2">false</span>;}</span></span>

匿名委托：

<span style="background-color:#282c34"><span style="color:#abb2bf">List<<span style="color:#e6c07b">string</span>> subList = mList.<span style="color:#e2b93d">FindAll( delegate(string name)</span> {Console.<span style="color:#e2b93d">WriteLine(name)</span>;<span style="color:#f92672">if</span> (name.Length > <span style="color:#d19a66">3</span>){return <span style="color:#56b6c2">true</span>;}return <span style="color:#56b6c2">false</span>;
});</span></span>

Lambda表达式：

<span style="background-color:#282c34"><span style="color:#abb2bf">List<string> subList = mList.FindAll(<span style="color:#61aeee"><span style="color:#a6e22e">name</span> =></span> {<span style="color:#e6c07b">Console</span>.WriteLine(name);<span style="color:#f92672">if</span> (name.<span style="color:#e6c07b">Length</span> > <span style="color:#d19a66">3</span>){<span style="color:#f92672">return</span> <span style="color:#56b6c2">true</span>;}<span style="color:#f92672">return</span> <span style="color:#56b6c2">false</span>;
});</span></span>

13：List.Find 方法：搜索与指定谓词所定义的条件相匹配的元素，并返回整个 List 中的第一个匹配元素。

语法：public T Find(Predicate<T> match);

<span style="background-color:#282c34"><span style="color:#abb2bf"><span style="color:#e6c07b">string</span> listFind1 = mList.<span style="color:#e2b93d">Find(ListFind)</span>;  <span style="color:#b18eb1"><em>//委托给ListFind函数</em></span>
Console.<span style="color:#e2b93d">WriteLine(listFind1)</span>;</span></span>

14：List.FindLast 方法：搜索与指定谓词所定义的条件相匹配的元素，并返回整个 List 中的最后一个匹配元素。

语法：public T FindLast(Predicate<T> match);

<span style="background-color:#282c34"><span style="color:#abb2bf"><span style="color:#e6c07b">string</span> listFind2 = mList.<span style="color:#e2b93d">FindLast(ListFind)</span>;  <span style="color:#b18eb1"><em>//委托给ListFind函数</em></span>
Console.<span style="color:#e2b93d">WriteLine(listFind2)</span>;</span></span>

15：List.TrueForAll方法：确定是否 List 中的每个元素都与指定的谓词所定义的条件相匹配。

语法：public bool TrueForAll(Predicate<T> match);

<span style="background-color:#282c34"><span style="color:#abb2bf"><span style="color:#e6c07b">bool</span> flag = mList.<span style="color:#e2b93d">TrueForAll(delegate(string name)</span>
{Console.<span style="color:#e2b93d">WriteLine(name)</span>;<span style="color:#f92672">if</span> (name.Length > <span style="color:#d19a66">3</span>){return <span style="color:#56b6c2">true</span>;}return <span style="color:#56b6c2">false</span>;
});</span></span>

16：List.Take(n)方法：获得前n行返回值为IEnumetable<T>，T的类型与List<T>的类型一样：就是复制

<span style="background-color:#282c34"><span style="color:#abb2bf">            IEnumerable<<span style="color:#e6c07b">string</span>> mmmlist = mList.Take(<span style="color:#d19a66">3</span>);foreach (<span style="color:#e6c07b">string</span> <span style="color:#e6c07b">item</span> <span style="color:#f92672">in</span> mmmlist){Console.WriteLine(<span style="color:#e6c07b">item</span>);}Console.WriteLine(<span style="color:#98c379">"
"</span>);</span></span>

17：List.Where方法：检索与指定谓词所定义的条件相匹配的所有元素。跟List.FindAll方法类似。

使用该方法定义存储集合的元素开头是：IEnumerable

<span style="background-color:#282c34"><span style="color:#abb2bf">            IEnumerable<<span style="color:#e6c07b">string</span>> whereList = mList.Where(ListFind);foreach (var <span style="color:#e6c07b">item</span> <span style="color:#f92672">in</span> whereList){Console.WriteLine(<span style="color:#e6c07b">item</span>);}Console.WriteLine(<span style="color:#98c379">"
"</span>);</span></span>

18：List.RemoveAll方法：移除与指定的谓词所定义的条件相匹配的所有元素。

语法： public int RemoveAll(Predicate<T> match);

<span style="background-color:#282c34"><span style="color:#abb2bf">            mList.RemoveAll<span style="color:#e6c07b">(name</span> => {<span style="color:#f92672">if</span> <span style="color:#e6c07b">(name</span>.Length <= <span style="color:#d19a66">6</span>){<span style="color:#f92672">return</span><span style="color:#e6c07b"> true</span>;}<span style="color:#f92672">else</span> {<span style="color:#f92672">return</span><span style="color:#e6c07b"> false</span>;}});foreach (var <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> mList){Console.WriteLine(<span style="color:#d19a66">item</span>);}Console.WriteLine(<span style="color:#98c379">"
"</span>);</span></span>

测试使用全部代码：

<span style="background-color:#282c34"><span style="color:#abb2bf"><span style="color:#d19a66">using</span> <span style="color:#e6c07b">System</span>;
<span style="color:#d19a66">using</span> <span style="color:#e6c07b">System</span>.Collections.Generic;
<span style="color:#d19a66">using</span> <span style="color:#e6c07b">System</span>.Linq;
<span style="color:#d19a66">using</span> <span style="color:#e6c07b">System</span>.Text;
<span style="color:#d19a66">using</span> <span style="color:#e6c07b">System</span>.Threading.Tasks;<span style="color:#d19a66">namespace</span> <span style="color:#61aeee">listys</span>
{<span style="color:#f92672">class</span> <span style="color:#e6c07b">Program</span>{<span style="color:#f92672">static</span> <span style="color:#d19a66">void</span> <span style="color:#e6c07b">Main</span>(<span style="color:#d19a66">string</span>[] <span style="color:#d19a66">args</span>){<span style="color:#b18eb1"><em>// 声明列表</em></span><span style="color:#b18eb1"><em>// List<string> mList = new List<string>();</em></span><span style="color:#d19a66">string</span>[] <span style="color:#d19a66">arr</span> <span style="color:#f92672">=</span> { <span style="color:#98c379">"Ha"</span>, <span style="color:#98c379">"Hunter"</span>, <span style="color:#98c379">"Tom"</span>, <span style="color:#98c379">"Lily"</span>, <span style="color:#98c379">"Jay"</span>, <span style="color:#98c379">"Jim"</span>, <span style="color:#98c379">"Kuku"</span>, <span style="color:#98c379">"Locu"</span> };<span style="color:#e6c07b">List</span><span style="color:#f92672"><</span><span style="color:#d19a66">string</span><span style="color:#f92672">></span> <span style="color:#d19a66">mList</span> <span style="color:#f92672">=</span> <span style="color:#d19a66">new</span> <span style="color:#e6c07b">List</span><span style="color:#f92672"><</span><span style="color:#d19a66">string</span><span style="color:#f92672">></span>(<span style="color:#d19a66">arr</span>);<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">mList</span>.Count);<span style="color:#d19a66">mList</span>.Add(<span style="color:#98c379">"cmailla"</span>);<span style="color:#61aeee">foreach</span> (<span style="color:#d19a66">string</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">mList</span>.Insert(<span style="color:#d19a66">0</span>,<span style="color:#98c379">"qwert"</span>);<span style="color:#61aeee">foreach</span> (<span style="color:#d19a66">string</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">string</span>[] <span style="color:#d19a66">dfg</span> <span style="color:#f92672">=</span> { <span style="color:#98c379">"hiocvhi"</span>,<span style="color:#98c379">"jioosdfhio"</span>,<span style="color:#98c379">"erw"</span>};<span style="color:#d19a66">mList</span>.AddRange(<span style="color:#d19a66">dfg</span>);<span style="color:#61aeee">foreach</span> (<span style="color:#d19a66">string</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">mList</span>.Remove(<span style="color:#98c379">"erw"</span>);<span style="color:#61aeee">foreach</span> (<span style="color:#d19a66">string</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">mList</span>.RemoveAt(<span style="color:#d19a66">3</span>);<span style="color:#61aeee">foreach</span> (<span style="color:#d19a66">string</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">mList</span>.RemoveRange(<span style="color:#d19a66">3</span>,<span style="color:#d19a66">5</span>);<span style="color:#61aeee">foreach</span> (<span style="color:#d19a66">string</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">bool</span> <span style="color:#d19a66">s</span> <span style="color:#f92672">=</span> <span style="color:#d19a66">mList</span>.Contains(<span style="color:#98c379">"Ha"</span>);<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">s</span>);<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">mList</span>.Sort();<span style="color:#61aeee">foreach</span> (<span style="color:#f92672">var</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">mList</span>.Reverse();<span style="color:#61aeee">foreach</span> (<span style="color:#f92672">var</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#b18eb1"><em>/*mList.Clear();foreach (var item in mList){Console.WriteLine(item);}Console.WriteLine("
");//*/</em></span><span style="color:#b18eb1"><em>// 正常委托</em></span><span style="color:#b18eb1"><em>// List<string> subList = mList.FindAll(ListFind); //委托给ListFind函数</em></span><span style="color:#b18eb1"><em>// 匿名委托</em></span><span style="color:#b18eb1"><em>/*List<string> subList = mList.FindAll( delegate(string name) {Console.WriteLine(name);if (name.Length > 3){return true;}return false;});//*/</em></span><span style="color:#e6c07b">List</span><span style="color:#f92672"><</span><span style="color:#d19a66">string</span><span style="color:#f92672">></span> <span style="color:#d19a66">subList</span> <span style="color:#f92672">=</span> <span style="color:#d19a66">mList</span>.FindAll(<span style="color:#d19a66">name</span> <span style="color:#f92672">=</span><span style="color:#f92672">></span> {<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">name</span>);<span style="color:#f92672">if</span> (<span style="color:#d19a66">name</span>.Length <span style="color:#f92672">></span> <span style="color:#d19a66">3</span>){<span style="color:#f92672">return</span> <span style="color:#56b6c2">true</span>;}<span style="color:#f92672">return</span> <span style="color:#56b6c2">false</span>;});<span style="color:#61aeee">foreach</span> (<span style="color:#d19a66">string</span> <span style="color:#d19a66">sss</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">subList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"element in subList: "</span> <span style="color:#f92672">+</span> <span style="color:#d19a66">sss</span>);}<span style="color:#d19a66">string</span> <span style="color:#d19a66">listFind1</span> <span style="color:#f92672">=</span> <span style="color:#d19a66">mList</span>.Find(<span style="color:#e6c07b">ListFind</span>);  <span style="color:#b18eb1"><em>//委托给ListFind函数</em></span><span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">listFind1</span>);<span style="color:#d19a66">string</span> <span style="color:#d19a66">listFind2</span> <span style="color:#f92672">=</span> <span style="color:#d19a66">mList</span>.FindLast(<span style="color:#e6c07b">ListFind</span>);  <span style="color:#b18eb1"><em>//委托给ListFind函数</em></span><span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">listFind2</span>);<span style="color:#d19a66">bool</span> <span style="color:#d19a66">flag</span> <span style="color:#f92672">=</span> <span style="color:#d19a66">mList</span>.TrueForAll(<span style="color:#61aeee">delegate</span>(string name){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">name</span>);<span style="color:#f92672">if</span> (<span style="color:#d19a66">name</span>.Length <span style="color:#f92672">></span> <span style="color:#d19a66">3</span>){<span style="color:#f92672">return</span> <span style="color:#56b6c2">true</span>;}<span style="color:#f92672">return</span> <span style="color:#56b6c2">false</span>;});<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">flag</span>);<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#e6c07b">IEnumerable</span><span style="color:#f92672"><</span><span style="color:#d19a66">string</span><span style="color:#f92672">></span> <span style="color:#d19a66">mmmlist</span> <span style="color:#f92672">=</span> <span style="color:#d19a66">mList</span>.Take(<span style="color:#d19a66">3</span>);<span style="color:#61aeee">foreach</span> (<span style="color:#d19a66">string</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mmmlist</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#e6c07b">IEnumerable</span><span style="color:#f92672"><</span><span style="color:#d19a66">string</span><span style="color:#f92672">></span> <span style="color:#d19a66">whereList</span> <span style="color:#f92672">=</span> <span style="color:#d19a66">mList</span>.Where(<span style="color:#e6c07b">ListFind</span>);<span style="color:#61aeee">foreach</span> (<span style="color:#f92672">var</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">whereList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#d19a66">mList</span>.RemoveAll(<span style="color:#d19a66">name</span> <span style="color:#f92672">=</span><span style="color:#f92672">></span> {<span style="color:#f92672">if</span> (<span style="color:#d19a66">name</span>.Length <span style="color:#f92672"><=</span> <span style="color:#d19a66">6</span>){<span style="color:#f92672">return</span> <span style="color:#56b6c2">true</span>;}<span style="color:#f92672">else</span> {<span style="color:#f92672">return</span> <span style="color:#56b6c2">false</span>;}});<span style="color:#61aeee">foreach</span> (<span style="color:#f92672">var</span> <span style="color:#d19a66">item</span> <span style="color:#f92672">in</span> <span style="color:#d19a66">mList</span>){<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#d19a66">item</span>);}<span style="color:#e6c07b">Console</span>.WriteLine(<span style="color:#98c379">"
"</span>);<span style="color:#e6c07b">Console</span>.ReadLine();}<span style="color:#b18eb1"><em>//ListFind函数</em></span><span style="color:#d19a66">public</span> <span style="color:#f92672">static</span> <span style="color:#d19a66">bool</span> <span style="color:#e6c07b">ListFind</span>(<span style="color:#d19a66">string</span> <span style="color:#d19a66">name</span>){<span style="color:#f92672">if</span> (<span style="color:#d19a66">name</span>.Length <span style="color:#f92672">></span> <span style="color:#d19a66">3</span>){<span style="color:#f92672">return</span> <span style="color:#56b6c2">true</span>;}<span style="color:#f92672">return</span> <span style="color:#56b6c2">false</span>;}}
}</span></span>

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