blocks|key|1253000|text|if((int)letter+!=+0)+{+}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1253001|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((int)letter != 0) { }
</code></pre>

blocks|key|1253013|text|怎么样|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1253014|if+((letter+&+Letters.AB)+>+0)|code-block|syntax|javascript|1253015|1253016|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|K|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|L|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|M|8|@]|9|@]|A|$]]]|I|$]]

How about 

<pre><code>if ((letter &amp; Letters.AB) &gt; 0)
</code></pre>

?

blocks|key|1253047|text|如果它真的让你很恼火，你可以写一个这样的函数：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1253048|public+bool+IsSet(Letters+value,+Letters+flag)
{
++++return+(value+&+flag)+==+flag;
}

if+(IsSet(letter,+Letters.A))
{
+++//+...
}

//+If+you+want+to+check+if+BOTH+Letters.A+and+Letters.B+are+set:
if+(IsSet(letter,+Letters.A+&+Letters.B))
{
+++//+...
}

//+If+you+want+an+OR,+I'm+afraid+you+will+have+to+be+more+verbose:
if+(IsSet(letter,+Letters.A)+%7C%7C+IsSet(letter,+Letters.B))
{
+++//+...
}|code-block|syntax|javascript|1253049|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|$]]

If it really annoys you, you can write a function like that:

<pre><code>public bool IsSet(Letters value, Letters flag)
{
 return (value &amp; flag) == flag;
}

if (IsSet(letter, Letters.A))
{
 // ...
}

// If you want to check if BOTH Letters.A and Letters.B are set:
if (IsSet(letter, Letters.A &amp; Letters.B))
{
 // ...
}

// If you want an OR, I'm afraid you will have to be more verbose:
if (IsSet(letter, Letters.A) || IsSet(letter, Letters.B))
{
 // ...
}
</code></pre>

blocks|key|1467875|text|这对你有用吗？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1467876|if+((letter+&+(Letters.A+%7C+Letters.B))+!=+0)|code-block|syntax|javascript|1467877|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|$]]

Would this work for you?
<pre><code>if ((letter &amp; (Letters.A | Letters.B)) != 0)
</code></pre>

blocks|key|1253165|text|我使用扩展方法来编写类似这样的东西：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1253166|if+(letter.IsFlagSet(Letter.AB))
++++...|code-block|syntax|javascript|1253167|代码如下：|1253168|public+static+class+EnumExtensions
{
++++private+static+void+CheckIsEnum<T>(bool+withFlags)
++++{
++++++++if+(!typeof(T).IsEnum)
++++++++++++throw+new+ArgumentException(string.Format("Type+'{0}'+is+not+an+enum",+typeof(T).FullName));
++++++++if+(withFlags+&&+!Attribute.IsDefined(typeof(T),+typeof(FlagsAttribute)))
++++++++++++throw+new+ArgumentException(string.Format("Type+'{0}'+doesn't+have+the+'Flags'+attribute",+typeof(T).FullName));
++++}

++++public+static+bool+IsFlagSet<T>(this+T+value,+T+flag)+where+T+:+struct
++++{
++++++++CheckIsEnum<T>(true);
++++++++long+lValue+=+Convert.ToInt64(value);
++++++++long+lFlag+=+Convert.ToInt64(flag);
++++++++return+(lValue+&+lFlag)+!=+0;
++++}

++++public+static+IEnumerable<T>+GetFlags<T>(this+T+value)+where+T+:+struct
++++{
++++++++CheckIsEnum<T>(true);
++++++++foreach+(T+flag+in+Enum.GetValues(typeof(T)).Cast<T>())
++++++++{
++++++++++++if+(value.IsFlagSet(flag))
++++++++++++++++yield+return+flag;
++++++++}
++++}

++++public+static+T+SetFlags<T>(this+T+value,+T+flags,+bool+on)+where+T+:+struct
++++{
++++++++CheckIsEnum<T>(true);
++++++++long+lValue+=+Convert.ToInt64(value);
++++++++long+lFlag+=+Convert.ToInt64(flags);
++++++++if+(on)
++++++++{
++++++++++++lValue+%7C=+lFlag;
++++++++}
++++++++else
++++++++{
++++++++++++lValue+&=+(~lFlag);
++++++++}
++++++++return+(T)Enum.ToObject(typeof(T),+lValue);
++++}

++++public+static+T+SetFlags<T>(this+T+value,+T+flags)+where+T+:+struct
++++{
++++++++return+value.SetFlags(flags,+true);
++++}

++++public+static+T+ClearFlags<T>(this+T+value,+T+flags)+where+T+:+struct
++++{
++++++++return+value.SetFlags(flags,+false);
++++}

++++public+static+T+CombineFlags<T>(this+IEnumerable<T>+flags)+where+T+:+struct
++++{
++++++++CheckIsEnum<T>(true);
++++++++long+lValue+=+0;
++++++++foreach+(T+flag+in+flags)
++++++++{
++++++++++++long+lFlag+=+Convert.ToInt64(flag);
++++++++++++lValue+%7C=+lFlag;
++++++++}
++++++++return+(T)Enum.ToObject(typeof(T),+lValue);
++++}

++++public+static+string+GetDescription<T>(this+T+value)+where+T+:+struct
++++{
++++++++CheckIsEnum<T>(false);
++++++++string+name+=+Enum.GetName(typeof(T),+value);
++++++++if+(name+!=+null)
++++++++{
++++++++++++FieldInfo+field+=+typeof(T).GetField(name);
++++++++++++if+(field+!=+null)
++++++++++++{
++++++++++++++++DescriptionAttribute+attr+=+Attribute.GetCustomAttribute(field,+typeof(DescriptionAttribute))+as+DescriptionAttribute;
++++++++++++++++if+(attr+!=+null)
++++++++++++++++{
++++++++++++++++++++return+attr.Description;
++++++++++++++++}
++++++++++++}
++++++++}
++++++++return+null;
++++}
}|1253169|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 extension methods to write things like that :

<pre><code>if (letter.IsFlagSet(Letter.AB))
 ...
</code></pre>

Here's the code :

<pre><code>public static class EnumExtensions
{
 private static void CheckIsEnum&lt;T&gt;(bool withFlags)
 {
 if (!typeof(T).IsEnum)
 throw new ArgumentException(string.Format("Type '{0}' is not an enum", typeof(T).FullName));
 if (withFlags &amp;&amp; !Attribute.IsDefined(typeof(T), typeof(FlagsAttribute)))
 throw new ArgumentException(string.Format("Type '{0}' doesn't have the 'Flags' attribute", typeof(T).FullName));
 }

 public static bool IsFlagSet&lt;T&gt;(this T value, T flag) where T : struct
 {
 CheckIsEnum&lt;T&gt;(true);
 long lValue = Convert.ToInt64(value);
 long lFlag = Convert.ToInt64(flag);
 return (lValue &amp; lFlag) != 0;
 }

 public static IEnumerable&lt;T&gt; GetFlags&lt;T&gt;(this T value) where T : struct
 {
 CheckIsEnum&lt;T&gt;(true);
 foreach (T flag in Enum.GetValues(typeof(T)).Cast&lt;T&gt;())
 {
 if (value.IsFlagSet(flag))
 yield return flag;
 }
 }

 public static T SetFlags&lt;T&gt;(this T value, T flags, bool on) where T : struct
 {
 CheckIsEnum&lt;T&gt;(true);
 long lValue = Convert.ToInt64(value);
 long lFlag = Convert.ToInt64(flags);
 if (on)
 {
 lValue |= lFlag;
 }
 else
 {
 lValue &amp;= (~lFlag);
 }
 return (T)Enum.ToObject(typeof(T), lValue);
 }

 public static T SetFlags&lt;T&gt;(this T value, T flags) where T : struct
 {
 return value.SetFlags(flags, true);
 }

 public static T ClearFlags&lt;T&gt;(this T value, T flags) where T : struct
 {
 return value.SetFlags(flags, false);
 }

 public static T CombineFlags&lt;T&gt;(this IEnumerable&lt;T&gt; flags) where T : struct
 {
 CheckIsEnum&lt;T&gt;(true);
 long lValue = 0;
 foreach (T flag in flags)
 {
 long lFlag = Convert.ToInt64(flag);
 lValue |= lFlag;
 }
 return (T)Enum.ToObject(typeof(T), lValue);
 }

 public static string GetDescription&lt;T&gt;(this T value) where T : struct
 {
 CheckIsEnum&lt;T&gt;(false);
 string name = Enum.GetName(typeof(T), value);
 if (name != null)
 {
 FieldInfo field = typeof(T).GetField(name);
 if (field != null)
 {
 DescriptionAttribute attr = Attribute.GetCustomAttribute(field, typeof(DescriptionAttribute)) as DescriptionAttribute;
 if (attr != null)
 {
 return attr.Description;
 }
 }
 }
 return null;
 }
}
</code></pre>

blocks|key|1468030|text|在.NET+4中，您可以使用Enum.HasFlag+method：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1468031|using+System;

[Flags]+public+enum+Pet+{
+++None+=+0,
+++Dog+=+1,
+++Cat+=+2,
+++Bird+=+4,
+++Rabbit+=+8,
+++Other+=+16
}

public+class+Example
{
+++public+static+void+Main()
+++{
++++++//+Define+three+families:+one+without+pets,+one+with+dog+%2B+cat+and+one+with+a+dog+only
++++++Pet[]+petsInFamilies+=+{+Pet.None,+Pet.Dog+%7C+Pet.Cat,+Pet.Dog+};
++++++int+familiesWithoutPets+=+0;
++++++int+familiesWithDog+=+0;

++++++foreach+(Pet+petsInFamily+in+petsInFamilies)
++++++{
+++++++++//+Count+families+that+have+no+pets.+
+++++++++if+(petsInFamily.Equals(Pet.None))
++++++++++++familiesWithoutPets%2B%2B;
+++++++++//+Of+families+with+pets,+count+families+that+have+a+dog.+
+++++++++else+if+(petsInFamily.HasFlag(Pet.Dog))
++++++++++++familiesWithDog%2B%2B;
++++++}
++++++Console.WriteLine("{0}+of+{1}+families+in+the+sample+have+no+pets.",+
++++++++++++++++++++++++familiesWithoutPets,+petsInFamilies.Length);+++
++++++Console.WriteLine("{0}+of+{1}+families+in+the+sample+have+a+dog.",+
++++++++++++++++++++++++familiesWithDog,+petsInFamilies.Length);+++
+++}
}|code-block|syntax|javascript|1468032|该示例显示以下输出：|1468033|//+++++++1+of+3+families+in+the+sample+have+no+pets.+
//+++++++2+of+3+families+in+the+sample+have+a+dog.|1468034|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.enum.hasflag.aspx^0|E|J|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]]]

In .NET 4 you can use the <a href="http://msdn.microsoft.com/en-us/library/system.enum.hasflag.aspx">Enum.HasFlag method</a> : 

<pre><code>using System;

[Flags] public enum Pet {
 None = 0,
 Dog = 1,
 Cat = 2,
 Bird = 4,
 Rabbit = 8,
 Other = 16
}

public class Example
{
 public static void Main()
 {
 // Define three families: one without pets, one with dog + cat and one with a dog only
 Pet[] petsInFamilies = { Pet.None, Pet.Dog | Pet.Cat, Pet.Dog };
 int familiesWithoutPets = 0;
 int familiesWithDog = 0;

 foreach (Pet petsInFamily in petsInFamilies)
 {
 // Count families that have no pets. 
 if (petsInFamily.Equals(Pet.None))
 familiesWithoutPets++;
 // Of families with pets, count families that have a dog. 
 else if (petsInFamily.HasFlag(Pet.Dog))
 familiesWithDog++;
 }
 Console.WriteLine("{0} of {1} families in the sample have no pets.", 
 familiesWithoutPets, petsInFamilies.Length); 
 Console.WriteLine("{0} of {1} families in the sample have a dog.", 
 familiesWithDog, petsInFamilies.Length); 
 }
}
</code></pre>

The example displays the following output:

<pre><code>// 1 of 3 families in the sample have no pets. 
// 2 of 3 families in the sample have a dog.
</code></pre>

blocks|key|1253293|text|在.NET+4或更高版本中有HasFlag方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1253294|if(letter.HasFlag(Letters.AB))
{
}|code-block|syntax|javascript|1253295|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/system.enum.hasflag.aspx^0|E|7|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]]]]

There is <a href="http://msdn.microsoft.com/en-us/library/system.enum.hasflag.aspx" rel="noreferrer">HasFlag</a> method in .NET 4 or higher.

<pre><code>if(letter.HasFlag(Letters.AB))
{
}
</code></pre>

blocks|key|1253340|text|如果可以使用.NET+4或更高版本，请使用HasFlag()方法|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1253341|示例|1253342|letter.HasFlag(Letters.A+%7C+Letters.B)+//+both+A+and+B+must+be+set|code-block|syntax|javascript|1253343|相同于|1253344|letter.HasFlag(Letters.AB)|1253345|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|Q|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|R|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

If you can use .NET 4 or higher than use HasFlag() method

examples

<pre><code>letter.HasFlag(Letters.A | Letters.B) // both A and B must be set
</code></pre>

same as

<pre><code>letter.HasFlag(Letters.AB)
</code></pre>

blocks|key|1253390|text|我创建了一个简单的扩展方法，它不需要检查Enum类型：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1253391|public+static+bool+HasAnyFlag(this+Enum+value,+Enum+flags)
{
++++return
++++++++value+!=+null+&&+((Convert.ToInt32(value)+&+Convert.ToInt32(flags))+!=+0);
}|code-block|syntax|javascript|1253392|它也适用于可以为空的枚举。标准的HasFlag方法没有，所以我也创建了一个扩展来涵盖这一点。|1253393|public+static+bool+HasFlag(this+Enum+value,+Enum+flags)
{
++++int+f+=+Convert.ToInt32(flags);

++++return
++++++++value+!=+null+&&+((Convert.ToInt32(value)+&+f)+==+f);
}|1253394|一个简单的测试：|1253395|[Flags]
enum+Option
{
++++None+=+0x00,
++++One+=+0x01,
++++Two+=+0x02,
++++Three+=+One+%7C+Two,
++++Four+=+0x04
}

[TestMethod]
public+void+HasAnyFlag()
{
++++Option+o1+=+Option.One;
++++Assert.AreEqual(true,+o1.HasAnyFlag(Option.Three));
++++Assert.AreEqual(false,+o1.HasFlag(Option.Three));

++++o1+%7C=+Option.Two;
++++Assert.AreEqual(true,+o1.HasAnyFlag(Option.Three));
++++Assert.AreEqual(true,+o1.HasFlag(Option.Three));
}

[TestMethod]
public+void+HasAnyFlag_NullableEnum()
{
++++Option?+o1+=+Option.One;
++++Assert.AreEqual(true,+o1.HasAnyFlag(Option.Three));
++++Assert.AreEqual(false,+o1.HasFlag(Option.Three));

++++o1+%7C=+Option.Two;
++++Assert.AreEqual(true,+o1.HasAnyFlag(Option.Three));
++++Assert.AreEqual(true,+o1.HasFlag(Option.Three));
}|1253396|享受吧！|1253397|entityMap^0|K|4|0|0|G|7|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|14|8|@]|D|@]|E|$]]|$1|Q|3|R|5|H|7|15|8|@]|D|@]|E|$I|J]]|$1|S|3|T|5|6|7|16|8|@]|D|@]|E|$]]|$1|U|3|-4|5|6|7|17|8|@]|D|@]|E|$]]]|V|$]]

I created a simple extension method that does not need a check on <code>Enum</code> types:

<pre><code>public static bool HasAnyFlag(this Enum value, Enum flags)
{
 return
 value != null &amp;&amp; ((Convert.ToInt32(value) &amp; Convert.ToInt32(flags)) != 0);
}
</code></pre>

It also works on nullable enums. The standard <code>HasFlag</code> method does not, so I created an extension to cover that too.

<pre><code>public static bool HasFlag(this Enum value, Enum flags)
{
 int f = Convert.ToInt32(flags);

 return
 value != null &amp;&amp; ((Convert.ToInt32(value) &amp; f) == f);
}
</code></pre>

A simple test:

<pre><code>[Flags]
enum Option
{
 None = 0x00,
 One = 0x01,
 Two = 0x02,
 Three = One | Two,
 Four = 0x04
}

[TestMethod]
public void HasAnyFlag()
{
 Option o1 = Option.One;
 Assert.AreEqual(true, o1.HasAnyFlag(Option.Three));
 Assert.AreEqual(false, o1.HasFlag(Option.Three));

 o1 |= Option.Two;
 Assert.AreEqual(true, o1.HasAnyFlag(Option.Three));
 Assert.AreEqual(true, o1.HasFlag(Option.Three));
}

[TestMethod]
public void HasAnyFlag_NullableEnum()
{
 Option? o1 = Option.One;
 Assert.AreEqual(true, o1.HasAnyFlag(Option.Three));
 Assert.AreEqual(false, o1.HasFlag(Option.Three));

 o1 |= Option.Two;
 Assert.AreEqual(true, o1.HasAnyFlag(Option.Three));
 Assert.AreEqual(true, o1.HasFlag(Option.Three));
}
</code></pre>

Enjoy!

blocks|key|1468264|text|这里有很多答案，但我认为使用Flags最常用的方法是Letters.AB.HasFlag(letter)或(Letters.A+%7CLetters.B).HasFlag(Letters.A%7CLetters.B)，如果你还没有Letters.AB的话。letter.HasFlag(Letters.AB)只有在两者都有的情况下才能工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1468265|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|$]]

There are a lot of answers on here but I think the most idiomatic way to do this with Flags would be Letters.AB.HasFlag(letter) or (Letters.A | Letters.B).HasFlag(letter) if you didn't already have Letters.AB. letter.HasFlag(Letters.AB) only works if it has both.

blocks|key|1253583|text|抱歉，我会在VB中展示:)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1253584|+++<Flags()>+Public+Enum+Cnt+As+Integer
++++++++None+=+0
++++++++One+=+1
++++++++Two+=+2
++++++++Three+=+4
++++++++Four+=+8++++
++++End+Enum

++++Sub+Test()
++++Dim+CntValue+As+New+Cnt
++++CntValue+%2B=+Cnt.One
++++CntValue+%2B=+Cnt.Three
++++Console.WriteLine(CntValue)
++++End+Sub|code-block|syntax|javascript|1253585|CntValue+=5，因此枚举包含1%2B4|1253586|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|$]]

Sorry, but i will show it in VB :)

<pre><code> &lt;Flags()&gt; Public Enum Cnt As Integer
 None = 0
 One = 1
 Two = 2
 Three = 4
 Four = 8 
 End Enum

 Sub Test()
 Dim CntValue As New Cnt
 CntValue += Cnt.One
 CntValue += Cnt.Three
 Console.WriteLine(CntValue)
 End Sub
</code></pre>

CntValue = 5
So the enum contains 1 + 4

blocks|key|1468383|text|对于任何类型的枚举，您都可以在枚举上使用此扩展方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1468384|public+static+bool+IsSingle(this+Enum+value)
{
++++var+items+=+Enum.GetValues(value.GetType());
++++var+counter+=+0;
++++foreach+(var+item+in+items)
++++{
++++++++if+(value.HasFlag((Enum)item))
++++++++{
++++++++++++counter%2B%2B;
++++++++}
++++++++if+(counter+>+1)
++++++++{
++++++++++++return+false;
++++++++}
++++}
++++return+true;
}|code-block|syntax|javascript|1468385|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|$]]

You can use this extension method on enum, for any type of enums:

<pre><code>public static bool IsSingle(this Enum value)
{
 var items = Enum.GetValues(value.GetType());
 var counter = 0;
 foreach (var item in items)
 {
 if (value.HasFlag((Enum)item))
 {
 counter++;
 }
 if (counter &gt; 1)
 {
 return false;
 }
 }
 return true;
}
</code></pre>

blocks|key|1253696|text|从.Net+4开始，您可以使用速记版本，而无需显式指定&：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1253697|if(Letters.AB.HasFlag(Letters.C))|code-block|syntax|javascript|1253698|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|$]]

Starting with .Net 4, you can use a shorthand version without explicitly specifying &amp;:
<pre><code>if(Letters.AB.HasFlag(Letters.C))
</code></pre>

Let's say I have this enum:
<pre><code>[Flags]
enum Letters
{
 A = 1,
 B = 2,
 C = 4,
 AB = A | B,
 All = A | B | C,
}
</code></pre>
To check if for example <code>AB</code> is set I can do this:
<pre><code>if((letter &amp; Letters.AB) == Letters.AB)
</code></pre>
Is there a simpler way to check if any of the flags of a combined flag constant are set than the following?
<pre><code>if((letter &amp; Letters.A) == Letters.A || (letter &amp; Letters.B) == Letters.B)
</code></pre>
Could one for example swap the <code>&amp;</code> with something?

How to check if any flags of a flag combination are set?

假设我有这个枚举：[Flags]enum Letters{     A = 1,     B = 2,     C = 4,     AB = A | B,     All = A | B | C,}例如，要检查是否设置了AB，我可以这样做：if((letter & Letters.AB) == Letters.AB)...

问如何检查是否设置了标志组合的标志？
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何检查是否设置了标志组合的标志？EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问如何检查是否设置了标志组合的标志？
EN