StringCollection 类

定义

命名空间:: System.Collections.Specialized

程序集:: System.dll, System.Collections.Specialized.dll

程序集:: System.dll

程序集:: netstandard.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

表示字符串的集合。

public ref class StringCollection : System::Collections::IList

public class StringCollection : System.Collections.IList

[System.Serializable]
public class StringCollection : System.Collections.IList

type StringCollection = class
    interface ICollection
    interface IEnumerable
    interface IList

[<System.Serializable>]
type StringCollection = class
    interface IList
    interface ICollection
    interface IEnumerable

Public Class StringCollection
Implements IList

继承: Object
StringCollection

派生: System.Configuration.CommaDelimitedStringCollection

属性: SerializableAttribute

实现: ICollection IEnumerable IList

示例

下面的代码示例演示了多个属性和方法 StringCollection。

using System;
using System.Collections;
using System.Collections.Specialized;

public class SamplesStringCollection  {

   public static void Main()  {

      // Create and initializes a new StringCollection.
      StringCollection myCol = new StringCollection();

      // Add a range of elements from an array to the end of the StringCollection.
      String[] myArr = new String[] { "RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED" };
      myCol.AddRange( myArr );

      // Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine( "Displays the elements using foreach:" );
      PrintValues1( myCol );

      // Display the contents of the collection using the enumerator.
      Console.WriteLine( "Displays the elements using the IEnumerator:" );
      PrintValues2( myCol );

      // Display the contents of the collection using the Count and Item properties.
      Console.WriteLine( "Displays the elements using the Count and Item properties:" );
      PrintValues3( myCol );

      // Add one element to the end of the StringCollection and insert another at index 3.
      myCol.Add( "* white" );
      myCol.Insert( 3, "* gray" );

      Console.WriteLine( "After adding \"* white\" to the end and inserting \"* gray\" at index 3:" );
      PrintValues1( myCol );

      // Remove one element from the StringCollection.
      myCol.Remove( "yellow" );

      Console.WriteLine( "After removing \"yellow\":" );
      PrintValues1( myCol );

      // Remove all occurrences of a value from the StringCollection.
      int i = myCol.IndexOf( "RED" );
      while ( i > -1 )  {
         myCol.RemoveAt( i );
         i = myCol.IndexOf( "RED" );
      }

      // Verify that all occurrences of "RED" are gone.
      if ( myCol.Contains( "RED" ) )
         Console.WriteLine( "*** The collection still contains \"RED\"." );

      Console.WriteLine( "After removing all occurrences of \"RED\":" );
      PrintValues1( myCol );

      // Copy the collection to a new array starting at index 0.
      String[] myArr2 = new String[myCol.Count];
      myCol.CopyTo( myArr2, 0 );

      Console.WriteLine( "The new array contains:" );
      for ( i = 0; i < myArr2.Length; i++ )  {
         Console.WriteLine( "   [{0}] {1}", i, myArr2[i] );
      }
      Console.WriteLine();

      // Clears the entire collection.
      myCol.Clear();

      Console.WriteLine( "After clearing the collection:" );
      PrintValues1( myCol );
   }

   // Uses the foreach statement which hides the complexity of the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintValues1( StringCollection myCol )  {
      foreach ( Object obj in myCol )
         Console.WriteLine( "   {0}", obj );
      Console.WriteLine();
   }

   // Uses the enumerator.
   // NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   public static void PrintValues2( StringCollection myCol )  {
      StringEnumerator myEnumerator = myCol.GetEnumerator();
      while ( myEnumerator.MoveNext() )
         Console.WriteLine( "   {0}", myEnumerator.Current );
      Console.WriteLine();
   }

   // Uses the Count and Item properties.
   public static void PrintValues3( StringCollection myCol )  {
      for ( int i = 0; i < myCol.Count; i++ )
         Console.WriteLine( "   {0}", myCol[i] );
      Console.WriteLine();
   }
}

/*
This code produces the following output.

Displays the elements using foreach:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

Displays the elements using the IEnumerator:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

Displays the elements using the Count and Item properties:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

After adding "* white" to the end and inserting "* gray" at index 3:
   RED
   orange
   yellow
   * gray
   RED
   green
   blue
   RED
   indigo
   violet
   RED
   * white

After removing "yellow":
   RED
   orange
   * gray
   RED
   green
   blue
   RED
   indigo
   violet
   RED
   * white

After removing all occurrences of "RED":
   orange
   * gray
   green
   blue
   indigo
   violet
   * white

The new array contains:
   [0] orange
   [1] * gray
   [2] green
   [3] blue
   [4] indigo
   [5] violet
   [6] * white

After clearing the collection:

*/

Imports System.Collections
Imports System.Collections.Specialized

Public Class SamplesStringCollection

   Public Shared Sub Main()

      ' Create and initializes a new StringCollection.
      Dim myCol As New StringCollection()

      ' Add a range of elements from an array to the end of the StringCollection.
      Dim myArr() As String = {"RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED"}
      myCol.AddRange(myArr)

      ' Display the contents of the collection using foreach. This is the preferred method.
      Console.WriteLine("Displays the elements using foreach:")
      PrintValues1(myCol)

      ' Display the contents of the collection using the enumerator.
      Console.WriteLine("Displays the elements using the IEnumerator:")
      PrintValues2(myCol)

      ' Display the contents of the collection using the Count and Item properties.
      Console.WriteLine("Displays the elements using the Count and Item properties:")
      PrintValues3(myCol)

      ' Add one element to the end of the StringCollection and insert another at index 3.
      myCol.Add("* white")
      myCol.Insert(3, "* gray")

      Console.WriteLine("After adding ""* white"" to the end and inserting ""* gray"" at index 3:")
      PrintValues1(myCol)

      ' Remove one element from the StringCollection.
      myCol.Remove("yellow")

      Console.WriteLine("After removing ""yellow"":")
      PrintValues1(myCol)

      ' Remove all occurrences of a value from the StringCollection.
      Dim i As Integer = myCol.IndexOf("RED")
      While i > - 1
         myCol.RemoveAt(i)
         i = myCol.IndexOf("RED")
      End While

      ' Verify that all occurrences of "RED" are gone.
      If myCol.Contains("RED") Then
         Console.WriteLine("*** The collection still contains ""RED"".")
      End If 
      Console.WriteLine("After removing all occurrences of ""RED"":")
      PrintValues1(myCol)

      ' Copy the collection to a new array starting at index 0.
      Dim myArr2(myCol.Count) As String
      myCol.CopyTo(myArr2, 0)

      Console.WriteLine("The new array contains:")
      For i = 0 To myArr2.Length - 1
         Console.WriteLine("   [{0}] {1}", i, myArr2(i))
      Next i
      Console.WriteLine()

      ' Clears the entire collection.
      myCol.Clear()

      Console.WriteLine("After clearing the collection:")
      PrintValues1(myCol)
   End Sub


   ' Uses the foreach statement which hides the complexity of the enumerator.
   ' NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintValues1(myCol As StringCollection)
      Dim obj As [Object]
      For Each obj In  myCol
         Console.WriteLine("   {0}", obj)
      Next obj
      Console.WriteLine()
   End Sub


   ' Uses the enumerator. 
   ' NOTE: The foreach statement is the preferred way of enumerating the contents of a collection.
   Public Shared Sub PrintValues2(myCol As StringCollection)
      Dim myEnumerator As StringEnumerator = myCol.GetEnumerator()
      While myEnumerator.MoveNext()
         Console.WriteLine("   {0}", myEnumerator.Current)
      End While
      Console.WriteLine()
   End Sub


   ' Uses the Count and Item properties.
   Public Shared Sub PrintValues3(myCol As StringCollection)
      Dim i As Integer
      For i = 0 To myCol.Count - 1
         Console.WriteLine("   {0}", myCol(i))
      Next i
      Console.WriteLine()
   End Sub

End Class


'This code produces the following output.
'
'Displays the elements using foreach:
'   RED
'   orange
'   yellow
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'Displays the elements using the IEnumerator:
'   RED
'   orange
'   yellow
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'Displays the elements using the Count and Item properties:
'   RED
'   orange
'   yellow
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'After adding "* white" to the end and inserting "* gray" at index 3:
'   RED
'   orange
'   yellow
'   * gray
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'   * white
'
'After removing "yellow":
'   RED
'   orange
'   * gray
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'   * white
'
'After removing all occurrences of "RED":
'   orange
'   * gray
'   green
'   blue
'   indigo
'   violet
'   * white
'
'The new array contains:
'   [0] orange
'   [1] * gray
'   [2] green
'   [3] blue
'   [4] indigo
'   [5] violet
'   [6] * white
'
'After clearing the collection:
'

注解

StringCollection 接受 null 为有效值并允许重复元素。

字符串比较区分大小写。

可以使用整数索引访问此集合中的元素。此集合中的索引从零开始。

构造函数

名称	说明
StringCollection()	初始化 StringCollection 类的新实例。

属性

名称	说明
Count	获取包含在 .. 中的 StringCollection字符串数。
IsReadOnly	获取一个值，该值指示是否 StringCollection 为只读。
IsSynchronized	获取一个值，该值指示是否同步对 StringCollection 的访问（线程安全）。
Item[Int32]	获取或设置指定索引处的元素。
SyncRoot	获取可用于同步对 . StringCollection的访问的对象。

方法

名称	说明
Add(String)	将字符串添加到该 StringCollection字符串的末尾。
AddRange(String[])	将字符串数组的元素复制到字符串 StringCollection数组的末尾。
Clear()	从 .中删除所有字符串 StringCollection。
Contains(String)	确定指定的字符串是否在 . 中 StringCollection。
CopyTo(String[], Int32)	从目标数组的指定索引处开始，将整个 StringCollection 值复制到字符串的一维数组。
Equals(Object)	确定指定的对象是否等于当前对象。 (继承自 Object)
GetEnumerator()	返回循环访问的StringCollection一个 StringEnumerator 。
GetHashCode()	用作默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
IndexOf(String)	搜索指定的字符串并返回第一个匹配项的 StringCollection从零开始的索引。
Insert(Int32, String)	将字符串插入 StringCollection 指定索引处。
MemberwiseClone()	创建当前 Object的浅表副本。 (继承自 Object)
Remove(String)	从中 StringCollection删除特定字符串的第一个匹配项。
RemoveAt(Int32)	删除指定索引处的 StringCollection字符串。
ToString()	返回一个表示当前对象的字符串。 (继承自 Object)

显式接口实现

名称	说明
ICollection.CopyTo(Array, Int32)	将整个 StringCollection 复制到兼容的一维 Array，从目标数组的指定索引处开始。
IEnumerable.GetEnumerator()	返回循环访问的StringCollection一个 IEnumerator 。
IList.Add(Object)	将对象添加到该 StringCollection对象的末尾。
IList.Contains(Object)	确定元素是否在 StringCollection.
IList.IndexOf(Object)	搜索指定的 Object 并返回整个 StringCollection匹配项中第一个匹配项的从零开始的索引。
IList.Insert(Int32, Object)	将元素 StringCollection 插入指定索引处。
IList.IsFixedSize	获取一个值，该值指示对象是否 StringCollection 具有固定大小。
IList.IsReadOnly	获取一个值，该值指示对象 StringCollection 是否为只读。
IList.Item[Int32]	获取或设置指定索引处的元素。
IList.Remove(Object)	从中 StringCollection删除特定对象的第一个匹配项。

扩展方法

名称	说明
AsParallel(IEnumerable)	启用查询的并行化。
AsQueryable(IEnumerable)	将 IEnumerable 转换为 IQueryable。
Cast<TResult>(IEnumerable)	将 IEnumerable 的元素强制转换为指定类型。
OfType<TResult>(IEnumerable)	根据指定类型筛选 IEnumerable 的元素。

适用于

线程安全性

此类型的公共静态（Shared 在 Visual Basic 中）成员是线程安全的。不能保证任何实例成员是线程安全的。

此实现不提供同步的（线程安全）包装器StringCollection，但派生类可以创建其自己的使用属性的StringCollection SyncRoot同步版本。

通过集合进行枚举本质上不是线程安全过程。即使集合同步，其他线程仍可以修改集合，这会导致枚举器引发异常。若要保证枚举期间的线程安全性，可以在整个枚举期间锁定集合，也可以捕获由其他线程所做的更改导致的异常。

另请参阅

执行 Culture-Insensitive 字符串操作

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