blocks|key|2597431|text|您需要使employeeList成为该类的成员变量：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2597432|class+EmployeeManager
{
++++//+Declare+this+at+the+class+level
++++List<string>+employeeList;

++++public+EmployeeManager()
++++{
+++++++++//+Assign,+but+do+not+redeclare+in+the+constructor
+++++++++employeeList+=+new+List<string>();
++++}

++++public+void+AddEmployee()
++++{
+++++++++//+This+now+exists+in+this+scope,+since+it's+part+of+the+class
+++++++++employeeList.add("Donald");
++++}
}|code-block|syntax|javascript|2597433|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 need to make employeeList a member variable of the class:

<pre><code>class EmployeeManager
{
 // Declare this at the class level
 List&lt;string&gt; employeeList;

 public EmployeeManager()
 {
 // Assign, but do not redeclare in the constructor
 employeeList = new List&lt;string&gt;();
 }

 public void AddEmployee()
 {
 // This now exists in this scope, since it's part of the class
 employeeList.add("Donald");
 }
}
</code></pre>

blocks|key|817878|text|您是否将employeeList声明为类的成员？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|817879|private+List<string>+employeeList+=+new+List<string();

public+EmployeeManager()
{

}

public+void+AddEmployee()
{
+++++employeeList.add("Donald");
}|code-block|syntax|javascript|817880|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|$]]

Did you declare the employeeList as a member of the class?

<pre><code>private List&lt;string&gt; employeeList = new List&lt;string();

public EmployeeManager()
{

}

public void AddEmployee()
{
 employeeList.add("Donald");
}
</code></pre>

blocks|key|4005678|text|List<string>+employeeList+=+new+List<string>();+

public+EmployeeManager()+
{+
}+

public+void+AddEmployee()+
{+
+++++employeeList.add("Donald");+
}+|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4005679|或者，也可以|unstyled|4005680|List<string>+employeeList;

public+EmployeeManager()+
{+
+++++employeeList+=+new+List<string>();+
}+

public+void+AddEmployee()+
{+
+++++employeeList.add("Donald");+
}+|4005681|正如您所定义的，employeeList只存在于ctor中。一旦它完成，employeeList就会消失，它的内存就会被垃圾收集。通过将声明移动到类级别，它将在对象的整个生命周期中存在。|offset|length|style|CODE|4005682|entityMap^0|0|0|0|8|C|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|T|8|@$K|U|L|V|M|N]]|9|@]|A|$]]|$1|O|3|-4|5|F|7|W|8|@]|9|@]|A|$]]]|P|$]]

<pre><code>List&lt;string&gt; employeeList = new List&lt;string&gt;(); 

public EmployeeManager() 
{ 
} 

public void AddEmployee() 
{ 
 employeeList.add("Donald"); 
} 
</code></pre>

or, alternately

<pre><code>List&lt;string&gt; employeeList;

public EmployeeManager() 
{ 
 employeeList = new List&lt;string&gt;(); 
} 

public void AddEmployee() 
{ 
 employeeList.add("Donald"); 
} 
</code></pre>

As you defined it, <code>employeeList</code> lives only in the ctor. Once it completes, employeeList goes away and it's memory is garbabge collected. By moving the declaration to the class level, it lives for the whole life of the object.

blocks|key|815113|text|employeeList必须是您的类的成员|type|unstyled|depth|inlineStyleRanges|entityRanges|data|815114|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|$]]

employeeList must be a member of your class

blocks|key|2597598|text|在add+employee函数的作用域之外声明该列表。然后，如果你在构造函数中实例化它，你就没问题了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2597599|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|$]]

Declare the list outside the scope of the add employee function. Then if you instantiate it in the constructor, you'll be okay.

blocks|key|4005807|text|出现这个错误的原因是因为employeeList的作用域只在构造函数中。为了使用employeeList，必须在更大的范围内定义它，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4005808|class+EmployeeManager
{
++++private+List<string>+employeeList;

++++public+EmployeeManager()
++++{
+++++++++employeeList+=+new+List<string>();
++++}

++++public+void+AddEmployee()
++++{
+++++++++employeeList.add("Donald");
++++}
}|code-block|syntax|javascript|4005809|entityMap^0|C|C|14|C|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

The reason you are getting this error, is because the scope of <code>employeeList</code> is only in the constructor. In order to use <code>employeeList</code> it must be defined in a larger scope, like so:

<pre><code>class EmployeeManager
{
 private List&lt;string&gt; employeeList;

 public EmployeeManager()
 {
 employeeList = new List&lt;string&gt;();
 }

 public void AddEmployee()
 {
 employeeList.add("Donald");
 }
}
</code></pre>

blocks|key|2597669|text|你遇到的问题是作用域。当构造函数触发时，它会创建employeeList列表，然后退出。此时，employeeList将从内存(堆栈)中消失。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2597670|您需要的是在类级别声明employeeList，如下所示：|2597671|List<string>+employeeList+=+null;
public+EmployeeManager()
{
+++++employeeList+=+new+List<string>();
}

public+void+AddEmployee()
{
+++++employeeList.add("Donald");
}|code-block|syntax|javascript|2597672|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|$]]

The problem that you have is with scope. When the constructor fires, it creates the employeeList List, then exits. At that point, the employeeList disapears from memory (the stack).

What you need is to declare the employeeList at class level like this :

<pre><code>List&lt;string&gt; employeeList = null;
public EmployeeManager()
{
 employeeList = new List&lt;string&gt;();
}

public void AddEmployee()
{
 employeeList.add("Donald");
}
</code></pre>

blocks|key|2597687|text|您需要它是成员级别的变量|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2597688|public+class+EmployeeManager
{
++++private+List<string>+_employeeList;
++++public+EmployeeManager()++
++++{++
++++++++_employeeList+=+new+List<string>();++
++++}++

++++public+void+AddEmployee()++
++++{++
++++++++_employeeList.add("Donald");++
++++}+
}|code-block|syntax|javascript|2597689|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 need it to be a member level variable

<pre><code>public class EmployeeManager
{
 private List&lt;string&gt; _employeeList;
 public EmployeeManager() 
 { 
 _employeeList = new List&lt;string&gt;(); 
 } 

 public void AddEmployee() 
 { 
 _employeeList.add("Donald"); 
 } 
}
</code></pre>

blocks|key|4005880|text|您需要在Add方法可访问的作用域中实例化EmployeeManager+--您只需定义类即可。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4005881|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|$]]

You need to instantiate your EmployeeManager in a scope that is accessible by your Add method -- you are simply defining the class.

blocks|key|1564293|text|您的EmployeeManager类需要与employeeList对应的字段或属性。如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1564294|public+class+EmployeeManager
{
+++private+List<string>+employeeList;+//Create+Field

+++public+EmployeeManager()
+++{
+++++this.employeeList+=+new+List<string>();
+++}

+++public+void+AddEmployee()
+++{
+++++this.employeeList.Add("Donald");
+++}
}|code-block|syntax|javascript|1564295|entityMap^0|2|F|L|C|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

Your <code>EmployeeManager</code> class needs a field or property to correspond to <code>employeeList</code>. Like so:

<pre><code>public class EmployeeManager
{
 private List&lt;string&gt; employeeList; //Create Field

 public EmployeeManager()
 {
 this.employeeList = new List&lt;string&gt;();
 }

 public void AddEmployee()
 {
 this.employeeList.Add("Donald");
 }
}
</code></pre>

blocks|key|1560575|text|您遇到了称为变量作用域的东西。目前你的列表的作用域是构造器。您需要通过将其定义为类成员来将其范围扩大到类，其他答案已经提供了代码示例。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1560576|http://www.blackwasp.co.uk/CSharpVariableScopes.aspx|offset|length|1560577|http://msdn.microsoft.com/en-us/library/aa691132(VS.71).aspx|1560578|entityMap|0|LINK|mutability|MUTABLE|url|1^0|0|0|1G|0|0|0|1O|1|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Q|8|@]|9|@$D|R|E|S|1|T]]|A|$]]|$1|F|3|G|5|6|7|U|8|@]|9|@$D|V|E|W|1|X]]|A|$]]|$1|H|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|C]]|O|$5|K|L|M|A|$N|G]]]]

You've run into something known as variable scope. Currently your list is scoped to the constructor. You need to scope it to the class by defining it as a class member, other answers have provided code samples.

<a href="http://www.blackwasp.co.uk/CSharpVariableScopes.aspx" rel="nofollow noreferrer">http://www.blackwasp.co.uk/CSharpVariableScopes.aspx</a>

<a href="http://msdn.microsoft.com/en-us/library/aa691132(VS.71).aspx" rel="nofollow noreferrer">http://msdn.microsoft.com/en-us/library/aa691132(VS.71).aspx</a>

I am trying to program a simple employee registry and I want to use a generic List to "save" the persons I am creating.

The manager class got one constructor and one method (see below).
The constructor creates the List and the method adds to it, or should be adding to it.
The problem is that I cannot do it like below because Visual Studio says that employeeList does not exist in the current context. How am I else going to write this?

<pre><code>public EmployeeManager()
{
 List&lt;string&gt; employeeList = new List&lt;string&gt;();
}

public void AddEmployee()
{
 employeeList.add("Donald");
}
</code></pre>

How to add to a list not yet created. Please help!

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。

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我正在尝试编写一个简单的员工注册表，并希望使用通用列表来“保存”我正在创建的人员。manager类有一个构造函数和一个方法(见下文)。构造函数创建列表，方法添加到列表中，或者应该添加到列表中。问题是我不能像下面这样做，因为Visual Studio说employeeList在当前上下文中不存在。要不然我怎么写这篇文章呢...

问如何添加到尚未创建的列表。请帮帮我！
EN

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问如何添加到尚未创建的列表。请帮帮我！EN