blocks|key|1429598|text|Console.WriteLine(String, Object)使用.NET的“复合格式”特性，当您为它提供枚举值时，它应用“枚举格式字符串”|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1429599|如果可能，G或g将枚举项显示为字符串值，否则将显示当前实例的整数值。|blockquote|1429600|因此，您可以在字符串中嵌入{0:G}以替代枚举名称。虽然没有提到，但{0:G}等同于{0}，这就是您在使用Console.WriteLine("Name:+{0},...的示例中看到的。|BOLD|1429601|D或d以尽可能最短的表示形式将枚举项显示为整数值。|1429602|因此，您可以在字符串中嵌入{0:D}以替换枚举值。|1429603|entityMap|0|LINK|mutability|MUTABLE|url|https://msdn.microsoft.com/en-us/library/586y06yf(v=vs.110).aspx|1|https://msdn.microsoft.com/en-us/library/txafckwd(v=vs.110).aspx)|2|https://msdn.microsoft.com/en-us/library/c3s1ez6e(v=vs.110).aspx)^0|0|X|0|X|0|Z|D|1|1R|9|2|0|0|D|5|Y|5|16|3|1H|W|N|2|0|0|D|5|N|1|0^^$0|@$1|2|3|4|5|6|7|11|8|@$9|12|A|13|B|C]]|D|@$9|14|A|15|1|16]|$9|17|A|18|1|19]|$9|1A|A|1B|1|1C]]|E|$]]|$1|F|3|G|5|H|7|1D|8|@]|D|@]|E|$]]|$1|I|3|J|5|6|7|1E|8|@$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]|$9|1N|A|1O|B|K]]|D|@]|E|$]]|$1|L|3|M|5|H|7|1P|8|@]|D|@]|E|$]]|$1|N|3|O|5|6|7|1Q|8|@$9|1R|A|1S|B|C]|$9|1T|A|1U|B|K]]|D|@]|E|$]]|$1|P|3|-4|5|6|7|1V|8|@]|D|@]|E|$]]]|Q|$R|$5|S|T|U|E|$V|W]]|X|$5|S|T|U|E|$V|Y]]|Z|$5|S|T|U|E|$V|10]]]]

<a href="https://msdn.microsoft.com/en-us/library/586y06yf(v=vs.110).aspx" rel="nofollow"><code>Console.WriteLine(String, Object)</code></a> uses <a href="https://msdn.microsoft.com/en-us/library/txafckwd(v=vs.110).aspx" rel="nofollow">the "Composite Formatting" features of .NET</a>, and when you provide it an enum value, it applies <a href="https://msdn.microsoft.com/en-us/library/c3s1ez6e(v=vs.110).aspx" rel="nofollow">the "Enumeration Format Strings"</a>:

<blockquote>
 G or g 
 
 Displays the enumeration entry as a string value, if
 possible, and otherwise displays the integer value of the current
 instance. 
</blockquote>

Thus you can embed <code>{0:G}</code> in your string to substitute the enum name. Although not mentioned, <code>{0:G}</code> is equivalent to <code>{0}</code>, which is what you have observed in your example with <code>Console.WriteLine("Name: {0},...</code>.

<blockquote>
 D or d 
 
 Displays the enumeration entry as an integer value in the shortest
 representation possible.
</blockquote>

Thus you can embed <code>{0:D}</code> in your string to substitute the enum value.

blocks|key|2049080|text|该代码将显式地打印该值两次。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2049081|Console.WriteLine("Name:+{0},+Value:+{0:D}",+enumData.GetValue(i));|code-block|syntax|javascript|2049082|第一个{0}只打印原始值，第二个格式指定(D)。|offset|length|style|CODE|2049083|entityMap^0|0|0|3|3|L|1|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

The code is explicitly printing the value twice

<pre><code>Console.WriteLine("Name: {0}, Value: {0:D}", enumData.GetValue(i));
</code></pre>

The first <code>{0}</code> just print the raw value, the second has a formatting specified (<code>D</code>)

blocks|key|2800010|text|GetValue返回枚举值对象。此对象属于类(Enum类)，该类将转换为具有其名称的字符串，或转换为具有其值的整数。因此，当字符串格式需要一个字符串时，它就会得到该字符串。当它请求一个十进制(格式说明符D)时，枚举值给它默认的基础值，即Int32，它很容易转换成一个十进制。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|2800011|entityMap^0|D|2|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

GetValue returns an enumeration value object. This object is of a class (Enum class) that will cast to a string with its name, or cast to an integer with its value. So when the string formatting expects a string, it gets that. When it asks for a decimal (Format specifier D), the enum value gives it the default underlying value which is Int32, which easily casts to a Decimal.

blocks|key|2800051|text|这些值由给定的格式打印出来。尝试删除{0:D}，并仅使用{0}。与所创建的列表一样，为列表指定了以下类型：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2800052|++++++++Array+enumData+=+Enum.GetValues(e.GetType());|code-block|syntax|javascript|2800053|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 values are being printed out by the given formatting. Try removing the {0:D}, and only use {0}. As in the list that is created, the type is specified for the list in: 

<pre><code> Array enumData = Enum.GetValues(e.GetType());
</code></pre>

I am reading about enumerations in a book, and the following code example was given:

<pre><code>namespace FunWithEnums
{
 enum EmpType : byte
 {
 Manager = 10, 
 Grunt = 1,
 Contractor = 100,
 VicePresident = 9

 }
 class Program
 {
 static void Main(string[] args)
 {
 Console.WriteLine("**** Fun with Enums *****");

 EmpType emp = EmpType.Contractor;
 EvaluateEnum(emp);
 Console.ReadLine();
 }

 static void EvaluateEnum(System.Enum e)
 {
 Array enumData = Enum.GetValues(e.GetType());

 for (int i =0; i &lt; enumData.Length; i++)
 {
 Console.WriteLine("Name: {0}, Value: {0:D}", enumData.GetValue(i));
 }
 Console.WriteLine();
 }
}
</code></pre>

I'm very confused as to what is being printed out in the forloop.
The output is 

<blockquote>
 Name: Grunt, Value: 1
 
 Name: VicePresident, Value: 9
 
 Name: Manager, Value: 10
 
 Name: Contractor, Value: 100
</blockquote>

But how does it get both the name AND the value of each enumerated element? According to the Microsoft documentation, <code>Array enumData = Enum.GetValues(e.GetType());</code> should only return " an array of the values of the constants in a specified enumeration." I assume that by constants, it is referring to "Manager", "Grunt", "Contractor", "VicePresident", as opposed to 10, 1, 100 and 9. So why is it returning each pair instead of just the name of the employee type? Also, the output of the following code <code>Console.WriteLine(enumData.GetValue(1));</code> returns just one value, which is "VicePresident" and doesn't return the number 9 like it does in the forloop. Why is this?

Confusion about return value of Enum.GetValues()

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

文章

问答

视频

学习中心

腾讯云实验室

直播

竞赛

腾讯云代码分析专区

腾讯iOA零信任安全管理系统专区

腾讯云架构师技术同盟交流圈

腾讯云数据库专区

腾讯云顾问专区

腾讯云原生专区

腾讯混元专区

腾讯云TCE专区

腾讯云Lighthouse专区

腾讯云HAI专区

腾讯云Edgeone专区

腾讯云存储专区

腾讯云智能专区

腾讯轻联专区 

腾讯云开发专区

TAPD专区

腾讯轻量云游戏服专区

腾讯云最具价值专家

腾讯云架构师技术同盟

腾讯云创作之星

腾讯云开发者先锋

腾讯云代码助手

云原生构建

TAPD 敏捷项目管理

Cloud Studio

SDK中心

API中心

命令行工具

涵盖代码开发、场景应用、自动测试全流程，助你从零构建专属AI助手

一站式MCP教程库，解锁AI应用新玩法

我正在阅读一本书中有关枚举的内容，并给出了以下代码示例：namespace FunWithEnums{    enum EmpType : byte    {        Manager = 10,         Grunt = 1,        Contractor = 100,        VicePres...

问关于Enum.GetValues()返回值的混淆
EN

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问关于Enum.GetValues()返回值的混淆EN