blocks|key|1851346|text|var+numbers+=+new[]+{+0,+1,+2,+2,+2,+3,+4,+4,+5+};

var+uniqueNumbers+=
++++from+n+in+numbers
++++group+n+by+n+into+nGroup
++++where+nGroup.Count()+==+1
++++select+nGroup.Key;

//+{+0,+1,+3,+5+}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1851347|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>var numbers = new[] { 0, 1, 2, 2, 2, 3, 4, 4, 5 };

var uniqueNumbers =
 from n in numbers
 group n by n into nGroup
 where nGroup.Count() == 1
 select nGroup.Key;

// { 0, 1, 3, 5 }
</code></pre>

blocks|key|2065412|text|var+nums+=+new+int{+0...4,4,5};
var+distinct+=+nums.Distinct();|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|2065413|确保您使用的是Linq和.NET+Framework3.5。|unstyled|2065414|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>var nums = new int{ 0...4,4,5};
var distinct = nums.Distinct();
</code></pre>

make sure you're using Linq and .NET framework 3.5.

blocks|key|2065742|text|使用lambda..|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2065743|var+all+=+new[]+{0,1,1,2,3,4,4,4,5,6,7,8,8}.ToList();
var+unique+=+all.GroupBy(i+=>+i).Where(i+=>+i.Count()+==+1).Select(i=>i.Key);|code-block|syntax|javascript|2065744|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|$]]

With lambda..

<pre><code>var all = new[] {0,1,1,2,3,4,4,4,5,6,7,8,8}.ToList();
var unique = all.GroupBy(i =&gt; i).Where(i =&gt; i.Count() == 1).Select(i=&gt;i.Key);
</code></pre>

blocks|key|2065665|text|C#+2.0解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2065666|static+IEnumerable<T>+GetUniques<T>(IEnumerable<T>+things)
{
++++Dictionary<T,+int>+counts+=+new+Dictionary<T,+int>();

++++foreach+(T+item+in+things)
++++{
++++++++int+count;
++++++++if+(counts.TryGetValue(item,+out+count))
++++++++++++counts[item]+=+%2B%2Bcount;
++++++++else
++++++++++++counts.Add(item,+1);
++++}

++++foreach+(KeyValuePair<T,+int>+kvp+in+counts)
++++{
++++++++if+(kvp.Value+==+1)
++++++++++++yield+return+kvp.Key;
++++}
}|code-block|syntax|javascript|2065667|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|$]]

C# 2.0 solution:

<pre><code>static IEnumerable&lt;T&gt; GetUniques&lt;T&gt;(IEnumerable&lt;T&gt; things)
{
 Dictionary&lt;T, int&gt; counts = new Dictionary&lt;T, int&gt;();

 foreach (T item in things)
 {
 int count;
 if (counts.TryGetValue(item, out count))
 counts[item] = ++count;
 else
 counts.Add(item, 1);
 }

 foreach (KeyValuePair&lt;T, int&gt; kvp in counts)
 {
 if (kvp.Value == 1)
 yield return kvp.Key;
 }
}
</code></pre>

blocks|key|1851650|text|如果列表中有复杂类型的对象，并且想要获取属性的唯一值，则可以使用以下另一种方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1851651|var+uniqueValues=+myItems.Select(k+=>+k.MyProperty)
++++++++++++++++++.GroupBy(g+=>+g)
++++++++++++++++++.Where(c+=>+c.Count()+==+1)
++++++++++++++++++.Select(k+=>+k.Key)
++++++++++++++++++.ToList();|code-block|syntax|javascript|1851652|或者获取不同的值：|1851653|var+distinctValues+=+myItems.Select(p+=>+p.MyProperty)
++++++++++++++++++++++++++++.Distinct()
++++++++++++++++++++++++++++.ToList();|1851654|如果您的属性也是复杂类型，则可以为Distinct()创建自定义比较器，例如Distinct(+OrderComparer+)，其中OrderComparer可能如下所示：|1851655|public+class+OrderComparer+:+IEqualityComparer<Order>
{
++++public+bool+Equals(Order+o1,+Order+o2)
++++{
++++++++return+o1.OrderID+==+o2.OrderID;
++++}

++++public+int+GetHashCode(Order+obj)
++++{
++++++++return+obj.OrderID.GetHashCode();
++++}
}|1851656|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

Here is another way that works if you have complex type objects in your List and want to get the unique values of a property: 

<pre><code>var uniqueValues= myItems.Select(k =&gt; k.MyProperty)
 .GroupBy(g =&gt; g)
 .Where(c =&gt; c.Count() == 1)
 .Select(k =&gt; k.Key)
 .ToList();
</code></pre>

Or to get distinct values:

<pre><code>var distinctValues = myItems.Select(p =&gt; p.MyProperty)
 .Distinct()
 .ToList();
</code></pre>

If your property is also a complex type you can create a custom comparer for the Distinct(), such as Distinct(OrderComparer), where OrderComparer could look like:

<pre><code>public class OrderComparer : IEqualityComparer&lt;Order&gt;
{
 public bool Equals(Order o1, Order o2)
 {
 return o1.OrderID == o2.OrderID;
 }

 public int GetHashCode(Order obj)
 {
 return obj.OrderID.GetHashCode();
 }
}
</code></pre>

blocks|key|2065499|text|如果Linq不可用，因为您必须支持无法升级的遗留代码，那么声明一个Dictionary，其中第一个int是数字，第二个int是出现的次数。循环遍历列表，加载字典。完成后，循环遍历Dictionary，只选择出现次数为1的元素。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2065500|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

If Linq isn't available to you because you have to support legacy code that can't be upgraded, then declare a Dictionary, where the first int is the number and the second int is the number of occurences. Loop through your List, loading up your Dictionary. When you're done, loop through your Dictionary selecting only those elements where the number of occurences is 1.

blocks|key|1851593|text|我相信马特的意思是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1851594|+static+IEnumerable<T>+GetUniques<T>(IEnumerable<T>+things)
+{
+++++Dictionary<T,+bool>+uniques+=+new+Dictionary<T,+bool>();
+++++foreach+(T+item+in+things)
+++++{
+++++++++if+(!(uniques.ContainsKey(item)))
+++++++++{
+++++++++++++uniques.Add(item,+true);
+++++++++}
+++++}
+++++return+uniques.Keys;
+}|code-block|syntax|javascript|1851595|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|$]]

I believe Matt meant to say:

<pre><code> static IEnumerable&lt;T&gt; GetUniques&lt;T&gt;(IEnumerable&lt;T&gt; things)
 {
 Dictionary&lt;T, bool&gt; uniques = new Dictionary&lt;T, bool&gt;();
 foreach (T item in things)
 {
 if (!(uniques.ContainsKey(item)))
 {
 uniques.Add(item, true);
 }
 }
 return uniques.Keys;
 }
</code></pre>

blocks|key|2065825|text|给猫剥皮的方法有很多种，但HashSet似乎很适合这方面的任务。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2065826|var+numbers+=+new[]+{+0,+1,+2,+2,+2,+3,+4,+4,+5+};

HashSet<int>+r+=+new+HashSet<int>(numbers);

foreach(+int+i+in+r+)+{
++++Console.Write(+"{0}+",+i+);
}|code-block|syntax|javascript|2065827|输出：|2065828|0+1+2+3+4+5|2065829|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|$]]

There are many ways to skin a cat, but HashSet seems made for the task here. 

<pre><code>var numbers = new[] { 0, 1, 2, 2, 2, 3, 4, 4, 5 };

HashSet&lt;int&gt; r = new HashSet&lt;int&gt;(numbers);

foreach( int i in r ) {
 Console.Write( "{0} ", i );
}
</code></pre>

The output:

0 1 2 3 4 5

blocks|key|2065749|text|在.Net+2.0中，我非常确定这个解决方案：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2065750|public+IEnumerable<T>+Distinct<T>(IEnumerable<T>+source)
{
+++++List<T>+uniques+=+new+List<T>();
+++++foreach+(T+item+in+source)
+++++{
+++++++++if+(!uniques.Contains(item))+uniques.Add(item);
+++++}
+++++return+uniques;
}|code-block|syntax|javascript|2065751|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|$]]

In .Net 2.0 I`m pretty sure about this solution:

<pre><code>public IEnumerable&lt;T&gt; Distinct&lt;T&gt;(IEnumerable&lt;T&gt; source)
{
 List&lt;T&gt; uniques = new List&lt;T&gt;();
 foreach (T item in source)
 {
 if (!uniques.Contains(item)) uniques.Add(item);
 }
 return uniques;
}
</code></pre>

How do I select the unique elements from the list <code>{0, 1, 2, 2, 2, 3, 4, 4, 5}</code> so that I get <code>{0, 1, 3, 5}</code>, effectively removing all instances of the repeated elements <code>{2, 4}</code>?

Selecting Unique Elements From a List in C#

如何从列表{0, 1, 2, 2, 2, 3, 4, 4, 5}中选择唯一的元素，以便获得{0, 1, 3, 5}，从而有效地删除重复元素{2, 4}的所有实例

问从C#中的列表中选择唯一元素
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