blocks|key|996878|text|public+static+bool+IsNullOrEmpty<T>(this+IEnumerable<T>+enumerable)+{
++++return+enumerable+==+null+%7C%7C+!enumerable.Any();
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|996879|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>public static bool IsNullOrEmpty&lt;T&gt;(this IEnumerable&lt;T&gt; enumerable) {
 return enumerable == null || !enumerable.Any();
}
</code></pre>

blocks|key|782665|text|这是@Matt+Greer有用答案的修改版本，其中包括一个静态包装器类，这样您就可以将其复制粘贴到新的源文件中，不依赖于Linq，并添加了一个泛型IEnumerable<T>重载，以避免非泛型版本中值类型的装箱。[编辑:请注意，使用IEnumerable<T>并不会阻止枚举数的装箱，duck-typing也无法阻止这一点，但至少值类型集合中的元素不会分别装箱。]|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|782666|using+System.Collections;
using+System.Collections.Generic;

public+static+class+IsNullOrEmptyExtension
{
++++public+static+bool+IsNullOrEmpty(this+IEnumerable+source)
++++{
++++++++if+(source+!=+null)
++++++++{
++++++++++++foreach+(object+obj+in+source)
++++++++++++{
++++++++++++++++return+false;
++++++++++++}
++++++++}
++++++++return+true;
++++}

++++public+static+bool+IsNullOrEmpty<T>(this+IEnumerable<T>+source)
++++{
++++++++if+(source+!=+null)
++++++++{
++++++++++++foreach+(T+obj+in+source)
++++++++++++{
++++++++++++++++return+false;
++++++++++++}
++++++++}
++++++++return+true;
++++}
}|code-block|syntax|javascript|782667|entityMap|0|LINK|mutability|MUTABLE|url|http://blogs.msdn.com/b/ericlippert/archive/2011/06/30/following-the-pattern.aspx^0|21|E|38|E|3Y|B|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|G|5|H|7|10|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

Here's a modified version of @Matt Greer's useful answer that includes a static wrapper class so you can just copy-paste this into a new source file, doesn't depend on Linq, and adds a generic <code>IEnumerable&lt;T&gt;</code> overload, to avoid the boxing of value types that would occur with the non-generic version. [EDIT: Note that use of <code>IEnumerable&lt;T&gt;</code> does not prevent boxing of the enumerator, <a href="http://blogs.msdn.com/b/ericlippert/archive/2011/06/30/following-the-pattern.aspx">duck-typing</a> can't prevent that, but at least the elements in a value-typed collection will not each be boxed.]

<pre><code>using System.Collections;
using System.Collections.Generic;

public static class IsNullOrEmptyExtension
{
 public static bool IsNullOrEmpty(this IEnumerable source)
 {
 if (source != null)
 {
 foreach (object obj in source)
 {
 return false;
 }
 }
 return true;
 }

 public static bool IsNullOrEmpty&lt;T&gt;(this IEnumerable&lt;T&gt; source)
 {
 if (source != null)
 {
 foreach (T obj in source)
 {
 return false;
 }
 }
 return true;
 }
}
</code></pre>

blocks|key|782721|text|另一种方法是获取枚举数并调用MoveNext()方法来查看是否有任何项：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|782722|if+(mylist+!=+null+&&+mylist.GetEnumerator().MoveNext())
{
++++//+The+list+is+not+null+or+empty
}|code-block|syntax|javascript|782723|这对IEnumerable和IEnumerable都有效。|782724|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Another way would be to get the Enumerator and call the MoveNext() method to see if there are any items:

<pre><code>if (mylist != null &amp;&amp; mylist.GetEnumerator().MoveNext())
{
 // The list is not null or empty
}
</code></pre>

This works for IEnumerable as well as IEnumerable&lt;T&gt;.

blocks|key|997071|text|只需添加using+System.Linq，当您尝试访问IEnumerable中的可用方法时，就会看到神奇的事情发生了。添加它将使您能够访问名为Count()的方法，就这么简单。只需记住在调用count()之前检查null+value+:)|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|997072|entityMap^0|4|H|S|B|20|7|2O|7|2Z|A|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|G|$]]

just add <code>using System.Linq</code> and see the magic happening when you try to access the available methods in the <code>IEnumerable</code>. Adding this will give you access to method named <code>Count()</code> as simple as that. just remember to check for <code>null value</code> before calling <code>count()</code> :)

blocks|key|997114|text|我的做法是，利用一些现代的C#特性：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|997115|选项1)|997116|public+static+class+Utils+{
++++public+static+bool+IsNullOrEmpty<T>(this+IEnumerable<T>+list)+{
++++++++return+!(list?.Any()+??+false);
++++}
}|code-block|syntax|javascript|997117|选项2)|997118|public+static+class+Utils+{
++++public+static+bool+IsNullOrEmpty<T>(this+IEnumerable<T>+list)+{
++++++++return+!(list?.Any()).GetValueOrDefault();
++++}
}|997119|顺便说一句，永远不要仅仅为了检查集合是否为空而使用Count+==+0或Count()+==+0。始终使用Linq的.Any()|offset|length|style|CODE|997120|entityMap^0|0|0|0|0|0|P|A|10|C|1M|6|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|W|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|X|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|Y|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|Z|8|@$O|10|P|11|Q|R]|$O|12|P|13|Q|R]|$O|14|P|15|Q|R]]|9|@]|A|$]]|$1|S|3|-4|5|6|7|16|8|@]|9|@]|A|$]]]|T|$]]

The way I do it, taking advantage of some modern C# features:

Option 1)

<pre><code>public static class Utils {
 public static bool IsNullOrEmpty&lt;T&gt;(this IEnumerable&lt;T&gt; list) {
 return !(list?.Any() ?? false);
 }
}
</code></pre>

Option 2)

<pre><code>public static class Utils {
 public static bool IsNullOrEmpty&lt;T&gt;(this IEnumerable&lt;T&gt; list) {
 return !(list?.Any()).GetValueOrDefault();
 }
}
</code></pre>

And by the way, never use <code>Count == 0</code> or <code>Count() == 0</code> just to check if a collection is empty. Always use Linq's <code>.Any()</code>

blocks|key|782864|text|我使用简单的if来检查它。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|782865|查看我的解决方案|782866|foreach+(Pet+pet+in+v.Pets)
{
++++if+(pet+==+null)
++++{
++++++++Console.WriteLine("+No+pet");//+enumerator+is+empty
++++++++break;
++++}
++++Console.WriteLine("++{0}",+pet.Name);
}|code-block|syntax|javascript|782867|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I used simple if to check for it

check out my solution

<pre><code>foreach (Pet pet in v.Pets)
{
 if (pet == null)
 {
 Console.WriteLine(" No pet");// enumerator is empty
 break;
 }
 Console.WriteLine(" {0}", pet.Name);
}
</code></pre>

blocks|key|997214|text|我是在answer+by+@Matt+Greer的基础上构建的|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|997215|他完美地回答了操作员的问题。|997216|我想要这样的东西，同时保持Any的原始功能，同时检查null。我发布这篇文章是为了以防其他人需要类似的东西。|997217|具体地说，我希望仍然能够传入谓词。|997218|public+static+class+Utilities
{
++++///+<summary>
++++///+Determines+whether+a+sequence+has+a+value+and+contains+any+elements.
++++///+</summary>
++++///+<typeparam+name="TSource">The+type+of+the+elements+of+source.</typeparam>
++++///+<param+name="source">The+<see+cref="System.Collections.Generic.IEnumerable"/>+to+check+for+emptiness.</param>
++++///+<returns>true+if+the+source+sequence+is+not+null+and+contains+any+elements;+otherwise,+false.</returns>
++++public+static+bool+AnyNotNull<TSource>(this+IEnumerable<TSource>+source)
++++{
++++++++return+source?.Any()+==+true;
++++}

++++///+<summary>
++++///+Determines+whether+a+sequence+has+a+value+and+any+element+of+a+sequence+satisfies+a+condition.
++++///+</summary>
++++///+<typeparam+name="TSource">The+type+of+the+elements+of+source.</typeparam>
++++///+<param+name="source">An+<see+cref="System.Collections.Generic.IEnumerable"/>+whose+elements+to+apply+the+predicate+to.</param>
++++///+<param+name="predicate">A+function+to+test+each+element+for+a+condition.</param>
++++///+<returns>true+if+the+source+sequence+is+not+null+and+any+elements+in+the+source+sequence+pass+the+test+in+the+specified+predicate;+otherwise,+false.</returns>
++++public+static+bool+AnyNotNull<TSource>(this+IEnumerable<TSource>+source,+Func<TSource,+bool>+predicate)
++++{
++++++++return+source?.Any(predicate)+==+true;
++++}
}|code-block|syntax|javascript|997219|扩展方法的命名可能会更好。|997220|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/5047370/4267686^0|3|L|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@$A|Z|B|10|1|11]]|C|$]]|$1|D|3|E|5|6|7|12|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|13|8|@]|9|@]|C|$]]|$1|H|3|I|5|6|7|14|8|@]|9|@]|C|$]]|$1|J|3|K|5|L|7|15|8|@]|9|@]|C|$M|N]]|$1|O|3|P|5|6|7|16|8|@]|9|@]|C|$]]|$1|Q|3|-4|5|6|7|17|8|@]|9|@]|C|$]]]|R|$S|$5|T|U|V|C|$W|X]]]]

I built this off of the <a href="https://stackoverflow.com/a/5047370/4267686">answer by @Matt Greer</a>

He answered the OP's question perfectly.

I wanted something like this while maintaining the original capabilities of Any while also checking for null. I'm posting this in case anyone else needs something similar.

Specifically I wanted to still be able to pass in a predicate.

<pre class="lang-cs prettyprint-override"><code>public static class Utilities
{
 /// &lt;summary&gt;
 /// Determines whether a sequence has a value and contains any elements.
 /// &lt;/summary&gt;
 /// &lt;typeparam name="TSource"&gt;The type of the elements of source.&lt;/typeparam&gt;
 /// &lt;param name="source"&gt;The &lt;see cref="System.Collections.Generic.IEnumerable"/&gt; to check for emptiness.&lt;/param&gt;
 /// &lt;returns&gt;true if the source sequence is not null and contains any elements; otherwise, false.&lt;/returns&gt;
 public static bool AnyNotNull&lt;TSource&gt;(this IEnumerable&lt;TSource&gt; source)
 {
 return source?.Any() == true;
 }

 /// &lt;summary&gt;
 /// Determines whether a sequence has a value and any element of a sequence satisfies a condition.
 /// &lt;/summary&gt;
 /// &lt;typeparam name="TSource"&gt;The type of the elements of source.&lt;/typeparam&gt;
 /// &lt;param name="source"&gt;An &lt;see cref="System.Collections.Generic.IEnumerable"/&gt; whose elements to apply the predicate to.&lt;/param&gt;
 /// &lt;param name="predicate"&gt;A function to test each element for a condition.&lt;/param&gt;
 /// &lt;returns&gt;true if the source sequence is not null and any elements in the source sequence pass the test in the specified predicate; otherwise, false.&lt;/returns&gt;
 public static bool AnyNotNull&lt;TSource&gt;(this IEnumerable&lt;TSource&gt; source, Func&lt;TSource, bool&gt; predicate)
 {
 return source?.Any(predicate) == true;
 }
}
</code></pre>

The naming of the extension method could probably be better.

blocks|key|997244|text|这可能会有所帮助|type|unstyled|depth|inlineStyleRanges|entityRanges|data|997245|public+static+bool+IsAny<T>(this+IEnumerable<T>+enumerable)
{
++++return+enumerable?.Any()+==+true;
}

public+static+bool+IsNullOrEmpty<T>(this+IEnumerable<T>+enumerable)
{
++++return+enumerable?.Any()+!=+true;
}|code-block|syntax|javascript|997246|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|$]]

This may help

<pre><code>public static bool IsAny&lt;T&gt;(this IEnumerable&lt;T&gt; enumerable)
{
 return enumerable?.Any() == true;
}

public static bool IsNullOrEmpty&lt;T&gt;(this IEnumerable&lt;T&gt; enumerable)
{
 return enumerable?.Any() != true;
}
</code></pre>

blocks|key|997298|text|我使用Bool+IsCollectionNullOrEmpty+=+!(Collection?.Any()??false);。希望这能有所帮助。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|997299|细目：|997300|如果集合为空，则Collection?.Any()将返回null；如果集合为空，则返回false。|997301|如果集合为空，Collection?.Any()??false将为我们提供false，如果集合为null，则为false。|997302|这样我们就可以得到IsEmptyOrNull了。|997303|entityMap^0|3|1N|0|0|8|H|S|4|17|5|0|7|O|11|5|1C|4|1J|5|0|9|D|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|T|8|@$9|U|A|V|B|C]|$9|W|A|X|B|C]|$9|Y|A|Z|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|10|8|@$9|11|A|12|B|C]|$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@]|E|$]]|$1|L|3|M|5|6|7|19|8|@$9|1A|A|1B|B|C]]|D|@]|E|$]]|$1|N|3|-4|5|6|7|1C|8|@]|D|@]|E|$]]]|O|$]]

I use <code>Bool IsCollectionNullOrEmpty = !(Collection?.Any()??false);</code>. Hope this helps.

Breakdown:

<code>Collection?.Any()</code> will return <code>null</code> if Collection is null, and <code>false</code> if Collection is empty.

<code>Collection?.Any()??false</code> will give us <code>false</code> if Collection is empty, and <code>false</code> if Collection is <code>null</code>.

Complement of that will give us <code>IsEmptyOrNull</code>.

blocks|key|997358|text|我也有同样的问题，我是这样解决的：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|997359|++++public+bool+HasMember(IEnumerable<TEntity>+Dataset)
++++{
++++++++return+Dataset+!=+null+&&+Dataset.Any(c=>c!=null);
++++}|code-block|syntax|javascript|997360|"c=>c!=+null“将忽略所有null实体。|997361|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

I had the same problem and I solve it like : 

<pre><code> public bool HasMember(IEnumerable&lt;TEntity&gt; Dataset)
 {
 return Dataset != null &amp;&amp; Dataset.Any(c=&gt;c!=null);
 }
</code></pre>

"c=>c!=null" will ignore all the null entities.

blocks|key|997378|text|下面的另一个最佳解决方案是检查是否为空？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|997379|for(var+item+in+listEnumerable)
{
+var+count=item.Length;
++if(count>0)
++{
+++++++++//+not+empty+or+null
+++}
++else
++{
+++++++//+empty
++}
}|code-block|syntax|javascript|997380|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|$]]

The other best solution as below to check empty or not ?

<pre><code>for(var item in listEnumerable)
{
 var count=item.Length;
 if(count&gt;0)
 {
 // not empty or null
 }
 else
 {
 // empty
 }
}
</code></pre>

blocks|key|783080|text|if+(collection?.Any()+==+true){
++++//+if+collection+contains+more+than+one+item
}
if+(collection?.Any()+!=+true){
++++//+if+collection+is+null
++++//+if+collection+does+not+contain+any+item
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|783081|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>if (collection?.Any() == true){
 // if collection contains more than one item
}
if (collection?.Any() != true){
 // if collection is null
 // if collection does not contain any item
}
</code></pre>

blocks|key|783095|text|我使用这个：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|783096|++++public+static+bool+IsNotEmpty(this+ICollection+elements)
++++{
++++++++return+elements+!=+null+&&+elements.Count+>+0;
++++}|code-block|syntax|javascript|783097|Ejem：|783098|List<string>+Things+=+null;
if+(Things.IsNotEmpty())
{
++++//replaces+->++if+(Things+!=+null+&&+Things.Count+>+0)+
}|783099|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|$]]

I use this one:

<pre><code> public static bool IsNotEmpty(this ICollection elements)
 {
 return elements != null &amp;&amp; elements.Count &gt; 0;
 }
</code></pre>

Ejem:

<pre><code>List&lt;string&gt; Things = null;
if (Things.IsNotEmpty())
{
 //replaces -&gt; if (Things != null &amp;&amp; Things.Count &gt; 0) 
}
</code></pre>

blocks|key|997504|text|由于一些资源在一次读取后耗尽，我想为什么不将检查和读取结合起来，而不是传统的单独检查，然后读取。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|997505|首先，我们有一个更简单的check-+for+-null内联扩展：|997506|public+static+System.Collections.Generic.IEnumerable<T>+ThrowOnNull<T>(this+System.Collections.Generic.IEnumerable<T>+source,+string+paramName+=+null)+=>+source+??+throw+new+System.ArgumentNullException(paramName+??+nameof(source));

var+first+=+source.ThrowOnNull().First();|code-block|syntax|javascript|997507|然后我们有了一个更复杂的(好吧，至少我写的方式)+check-for-null-and-empty内联扩展：|997508|public+static+System.Collections.Generic.IEnumerable<T>+ThrowOnNullOrEmpty<T>(this+System.Collections.Generic.IEnumerable<T>+source,+string+paramName+=+null)
{
++using+(var+e+=+source.ThrowOnNull(paramName).GetEnumerator())
++{
++++if+(!e.MoveNext())
++++{
++++++throw+new+System.ArgumentException(@"The+sequence+is+empty.",+paramName+??+nameof(source));
++++}

++++do
++++{
++++++yield+return+e.Current;
++++}
++++while+(e.MoveNext());
++}
}

var+first+=+source.ThrowOnNullOrEmpty().First();|997509|当然，您仍然可以在不继续调用链的情况下调用这两个函数。此外，我还包含了paramName，以便调用者可以包含错误的备用名称(如果它不是正在检查的“源”)，例如"nameof(target)“。|997510|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Since some resources are exhausted after one read, I thought why not combine the checks and the reads, instead of the traditional separate check, then read. 

First we have one for the simpler check-for-null inline extension:

<pre><code>public static System.Collections.Generic.IEnumerable&lt;T&gt; ThrowOnNull&lt;T&gt;(this System.Collections.Generic.IEnumerable&lt;T&gt; source, string paramName = null) =&gt; source ?? throw new System.ArgumentNullException(paramName ?? nameof(source));

var first = source.ThrowOnNull().First();
</code></pre>

Then we have the little more involved (well, at least the way I wrote it) check-for-null-and-empty inline extension:

<pre><code>public static System.Collections.Generic.IEnumerable&lt;T&gt; ThrowOnNullOrEmpty&lt;T&gt;(this System.Collections.Generic.IEnumerable&lt;T&gt; source, string paramName = null)
{
 using (var e = source.ThrowOnNull(paramName).GetEnumerator())
 {
 if (!e.MoveNext())
 {
 throw new System.ArgumentException(@"The sequence is empty.", paramName ?? nameof(source));
 }

 do
 {
 yield return e.Current;
 }
 while (e.MoveNext());
 }
}

var first = source.ThrowOnNullOrEmpty().First();
</code></pre>

You can of course still call both without continuing the call chain. Also, I included the paramName, so that the caller may include an alternate name for the error if it's not "source" being checked, e.g. "nameof(target)".

blocks|key|997521|text|+public+static+bool+AnyNotNull<TSource>(this+IEnumerable<TSource>+source)
++++{
++++++++return+source+!=+null+&&+source.Any();
++++}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|997522|我自己的扩展方法来检查Not+null和Any|unstyled|997523|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code> public static bool AnyNotNull&lt;TSource&gt;(this IEnumerable&lt;TSource&gt; source)
 {
 return source != null &amp;&amp; source.Any();
 }
</code></pre>

my own extension method to check Not null and Any

blocks|key|997574|text|Jon+Skeet的anwser+(https://stackoverflow.com/a/28904021/8207463)有一个很好的方法，它使用扩展方法-+Any()表示NULL和EMPTY。但他正在验证问题的所有者是否为NOT+NULL。因此，要小心地将Jon的验证为NULL的方法更改为：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|997575|If+(yourList?.Any()+!=+true)+
{
+++++..your+code...
}|code-block|syntax|javascript|997576|不使用(不会验证为NULL)：|997577|If+(yourList?.Any()+==+false)+
{
+++++..your+code...
}|997578|您还可以在情况下验证为NOT+NULL+(没有像示例一样测试，但没有编译器错误)，可以执行类似于使用谓词的操作：|997579|If+(yourList?.Any(p+=>+p.anyItem+==+null)+==+true)+
{
+++++..your+code...
}|997580|https://referencesource.microsoft.com/#System.Core/System/Linq/Enumerable.cs,8788153112b7ffd0|997581|您可以使用哪个.NET版本，请查看：|997582|https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.any?view=netframework-4.8#moniker-applies-to|997583|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/28904021/8207463|1|2^0|I|18|0|0|0|0|0|0|0|0|2L|1|0|0|0|33|2|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@$A|17|B|18|1|19]]|C|$]]|$1|D|3|E|5|F|7|1A|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|1B|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|1C|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|1D|8|@]|9|@]|C|$]]|$1|O|3|P|5|F|7|1E|8|@]|9|@]|C|$G|H]]|$1|Q|3|R|5|6|7|1F|8|@]|9|@$A|1G|B|1H|1|1I]]|C|$]]|$1|S|3|T|5|6|7|1J|8|@]|9|@]|C|$]]|$1|U|3|V|5|6|7|1K|8|@]|9|@$A|1L|B|1M|1|1N]]|C|$]]|$1|W|3|-4|5|6|7|1O|8|@]|9|@]|C|$]]]|X|$Y|$5|Z|10|11|C|$12|13]]|14|$5|Z|10|11|C|$12|R]]|15|$5|Z|10|11|C|$12|V]]]]

Jon Skeet's anwser (<a href="https://stackoverflow.com/a/28904021/8207463">https://stackoverflow.com/a/28904021/8207463</a>) has a good approach using Extension Method - Any() for NULL and EMPTY. BUT he´s validating the questions´owner in case for NOT NULL. 
So carefully change Jon´s approach to validate AS NULL to:

<pre><code>If (yourList?.Any() != true) 
{
 ..your code...
}
</code></pre>

DO NOT use ( will not validate AS NULL):

<pre><code>If (yourList?.Any() == false) 
{
 ..your code...
}
</code></pre>

You can also in case validating AS NOT NULL ( NOT tested just as example but without compiler error) do something like using predicate :

<pre><code>If (yourList?.Any(p =&gt; p.anyItem == null) == true) 
{
 ..your code...
}
</code></pre>

<a href="https://referencesource.microsoft.com/#System.Core/System/Linq/Enumerable.cs,8788153112b7ffd0" rel="nofollow noreferrer">https://referencesource.microsoft.com/#System.Core/System/Linq/Enumerable.cs,8788153112b7ffd0</a>

For which .NET version you can use it please check:

<a href="https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.any?view=netframework-4.8#moniker-applies-to" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.any?view=netframework-4.8#moniker-applies-to</a>

blocks|key|997622|text|我使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|997623|++++list.Where+(r=>r.value+==+value).DefaultIfEmpty().First()|code-block|syntax|javascript|997624|如果不匹配，则结果为null，否则返回其中一个对象|997625|如果你想要这个列表，我相信离开First()或者调用ToList()会提供这个列表或者是空的。|997626|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]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I use

<pre><code> list.Where (r=&gt;r.value == value).DefaultIfEmpty().First()
</code></pre>

The result will be null if no match, otherwise returns one of the objects

If you wanted the list, I believe leaving of First() or calling ToList() will provide the list or null.

blocks|key|783314|text|看看这个开源库：Nzr.ToolBox|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|783315|public+static+bool+IsEmpty(this+System.Collections.IEnumerable+enumerable)|code-block|syntax|javascript|783316|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/marionzr/Nzr.ToolBox/blob/a77202aa791d4397b18a3e8e60fc10cb056169cd/dotnet/Nzr.ToolBox.Core/CollectionUtils.cs#L340^0|8|B|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

Take a look at this opensource library: <a href="https://github.com/marionzr/Nzr.ToolBox/blob/a77202aa791d4397b18a3e8e60fc10cb056169cd/dotnet/Nzr.ToolBox.Core/CollectionUtils.cs#L340" rel="nofollow noreferrer">Nzr.ToolBox</a>

<pre><code>public static bool IsEmpty(this System.Collections.IEnumerable enumerable)
</code></pre>

blocks|key|783332|text|您可以使用此行进行验证|type|unstyled|depth|inlineStyleRanges|entityRanges|data|783333|myCollection?.FirstOrDefault()+==+null|code-block|syntax|javascript|783334|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|$]]

One can use this line for that verification
<pre class="lang-cs prettyprint-override"><code>myCollection?.FirstOrDefault() == null
</code></pre>

blocks|key|783368|text|it+null将返回true|type|unstyled|depth|inlineStyleRanges|entityRanges|data|783369|enter++++public+static+bool+IsNullOrEmpty<T>(this+IEnumerable<T>+enumerable)
++++{

++++++++try
++++++++{
++++++++++++return+enumerable?.Any()+!=+true;
++++++++}
++++++++catch+(Exception)
++++++++{

++++++++++++return+true;
++++++++}
+++
++++}|code-block|syntax|javascript|783370|代码在这里|783371|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

it null will return true
<pre><code>enter public static bool IsNullOrEmpty&lt;T&gt;(this IEnumerable&lt;T&gt; enumerable)
 {

 try
 {
 return enumerable?.Any() != true;
 }
 catch (Exception)
 {

 return true;
 }
 
 }
</code></pre>
code here

I love <code>string.IsNullOrEmpty</code> method. I'd love to have something that would allow the same functionality for IEnumerable. Is there such? Maybe some collection helper class? The reason I am asking is that in <code>if</code> statements the code looks cluttered if the patter is <code>(mylist != null &amp;&amp; mylist.Any())</code>. It would be much cleaner to have <code>Foo.IsAny(myList)</code>. 

This post doesn't give that answer: <a href="https://stackoverflow.com/questions/3779817/ienumerable-is-empty">IEnumerable is empty?</a>.

How to check if IEnumerable is null or empty?

编译器

我喜欢string.IsNullOrEmpty方法。我喜欢有一些东西，将允许相同的功能为IEnumerable。有这样的情况吗？也许是一些集合帮助器类？我问这个问题的原因是，如果模式是(mylist != null && mylist.Any())，那么在if语句中，代码看起来很混乱。如果有Foo.IsAny(myLi...

问如何检查IEnumerable是否为null或空？
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