StringCollection 类

项目
08/17/2007

表示字符串集合。

**命名空间:**System.Collections.Specialized
**程序集:**System（在 system.dll 中）

语法

声明
<SerializableAttribute> _
Public Class StringCollection
    Implements IList, ICollection, IEnumerable
用法
Dim instance As StringCollection

[SerializableAttribute] 
public class StringCollection : IList, ICollection, IEnumerable

[SerializableAttribute] 
public ref class StringCollection : IList, ICollection, IEnumerable

/** @attribute SerializableAttribute() */ 
public class StringCollection implements IList, ICollection, 
    IEnumerable

SerializableAttribute 
public class StringCollection implements IList, ICollection, 
    IEnumerable

备注

StringCollection 接受空引用（在 Visual Basic 中为 Nothing）作为有效值并且允许重复的元素。

字符串比较区分大小写。

可使用一个整数索引访问此集合中的元素。此集合中的索引从零开始。

示例

下面的代码示例阐释了 StringCollection 的几个属性和方法。

Imports System
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 'Main


   ' 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 'PrintValues1


   ' 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 'PrintValues2


   ' 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 'PrintValues3

End Class 'SamplesStringCollection 


'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:
'

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:

*/

#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;

void PrintValues1( StringCollection^ myCol );
void PrintValues2( StringCollection^ myCol );
void PrintValues3( StringCollection^ myCol );

int main()
{
   
   // Create and initializes a new StringCollection.
   StringCollection^ myCol = gcnew StringCollection;
   
   // Add a range of elements from an array to the end of the StringCollection.
   array<String^>^myArr = {"RED","orange","yellow","RED","green","blue","RED","indigo","violet","RED"};
   myCol->AddRange( myArr );
   
   // Display the contents of the collection using for each. This is the preferred method.
   Console::WriteLine( "Displays the elements using for each:" );
   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.
   array<String^>^myArr2 = gcnew array<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 for each statement which hides the complexity of the enumerator.
// NOTE: The for each statement is the preferred way of enumerating the contents of a collection.
void PrintValues1( StringCollection^ myCol )  {
   for each ( Object^ obj in myCol )
      Console::WriteLine( "   {0}", obj );
   Console::WriteLine();
}

// Uses the enumerator. 
void PrintValues2( StringCollection^ myCol )
{
   StringEnumerator^ myEnumerator = myCol->GetEnumerator();
   while ( myEnumerator->MoveNext() )
      Console::WriteLine( "   {0}", myEnumerator->Current );

   Console::WriteLine();
}


// Uses the Count and Item properties.
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 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:

*/

import System.* ;
import System.Collections.* ;
import System.Collections.Specialized.* ;

public class SamplesStringCollection
{
    public static void main(String[] args)
    {
        // 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 for:");
        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.get_Count()];

        myCol.CopyTo(myArr2, 0);
        Console.WriteLine("The new array contains:");
        for (i = 0; i < myArr2.length; i++) {
            Console.WriteLine("   [{0}] {1}", System.Convert.ToString(i), 
                myArr2.get_Item(i));
        }

        Console.WriteLine();

        // Clears the entire collection.
        myCol.Clear();
        Console.WriteLine("After clearing the collection:");
        PrintValues1(myCol);
    } //main

    public static void PrintValues1(StringCollection myCol)
    {
        Object obj = new Object();

        for (int iCtr = 0; iCtr < myCol.get_Count(); iCtr++) {
            obj = myCol.get_Item(iCtr);
            Console.WriteLine("   {0}", obj);
        }

        Console.WriteLine();
    } //PrintValues1

    // Uses the enumerator. 
    public static void PrintValues2(StringCollection myCol)
    {
        StringEnumerator myEnumerator = myCol.GetEnumerator();

        while (myEnumerator.MoveNext()) {
            Console.WriteLine("   {0}", myEnumerator.get_Current());
        }

        Console.WriteLine();
    } //PrintValues2

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

        Console.WriteLine();
    } //PrintValues3
} //SamplesStringCollection
 
/*
This code produces the following output.

Displays the elements using for:
   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:

*/

继承层次结构

System.Object
System.Collections.Specialized.StringCollection
System.Configuration.CommaDelimitedStringCollection

线程安全

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

此实现不为 StringCollection 提供同步（线程安全）包装，但派生类可使用 SyncRoot 属性创建它们各自的 StringCollection 同步版本。

从头到尾对一个集合进行枚举本质上并不是一个线程安全的过程。即使一个集合已进行同步，其他线程仍可以修改该集合，这将导致枚举数引发异常。若要在枚举过程中保证线程安全，可以在整个枚举过程中锁定集合，或者捕捉由于其他线程进行的更改而引发的异常。

平台

Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

通过

StringCollection 类

语法

备注

示例

继承层次结构

线程安全

平台

版本信息

.NET Framework

请参见

参考

其他资源

其他资源