ArrayList.TrimToSize 메서드

용량을 ArrayList의 실제 요소 수로 설정합니다.

네임스페이스: System.Collections
어셈블리: mscorlib(mscorlib.dll)

구문

‘선언
Public Overridable Sub TrimToSize
‘사용 방법
Dim instance As ArrayList

instance.TrimToSize

public virtual void TrimToSize ()

public:
virtual void TrimToSize ()

public void TrimToSize ()

public function TrimToSize ()

예외

예외 형식	조건
NotSupportedException	ArrayList가 읽기 전용인 경우 - 또는 - ArrayList의 크기가 고정되어 있는 경우

설명

이 메서드를 사용하면 컬렉션에 새로 추가되는 요소가 없을 경우 컬렉션의 메모리 오버헤드를 최소화할 수 있습니다.

ArrayList를 초기 상태로 다시 설정하려면 TrimToSize를 호출하기 전에 Clear 메서드를 호출합니다. 빈 ArrayList를 트리밍하면 ArrayList의 용량이 기본 용량으로 설정됩니다.

이 메서드는 O(n) 연산이며, 여기서 n은 Count입니다.

예제

다음 코드 예제에서는 ArrayList의 사용되지 않은 부분을 트리밍하는 방법과 ArrayList의 값을 지우는 방법을 보여 줍니다.

Imports System
Imports System.Collections
Imports Microsoft.VisualBasic

Public Class SamplesArrayList    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new ArrayList.
        Dim myAL As New ArrayList()
        myAL.Add("The")
        myAL.Add("quick")
        myAL.Add("brown")
        myAL.Add("fox")
        myAL.Add("jumped")
        
        ' Displays the count, capacity and values of the ArrayList.
        Console.WriteLine("Initially,")
        Console.WriteLine("   Count    : {0}", myAL.Count)
        Console.WriteLine("   Capacity : {0}", myAL.Capacity)
        Console.Write("   Values:")
        PrintValues(myAL)
        
        ' Trim the ArrayList.
        myAL.TrimToSize()
        
        ' Displays the count, capacity and values of the ArrayList.
        Console.WriteLine("After TrimToSize,")
        Console.WriteLine("   Count    : {0}", myAL.Count)
        Console.WriteLine("   Capacity : {0}", myAL.Capacity)
        Console.Write("   Values:")
        PrintValues(myAL)
        
        ' Clear the ArrayList.
        myAL.Clear()
        
        ' Displays the count, capacity and values of the ArrayList.
        Console.WriteLine("After Clear,")
        Console.WriteLine("   Count    : {0}", myAL.Count)
        Console.WriteLine("   Capacity : {0}", myAL.Capacity)
        Console.Write("   Values:")
        PrintValues(myAL)
        
        ' Trim the ArrayList again.
        myAL.TrimToSize()
        
        ' Displays the count, capacity and values of the ArrayList.
        Console.WriteLine("After the second TrimToSize,")
        Console.WriteLine("   Count    : {0}", myAL.Count)
        Console.WriteLine("   Capacity : {0}", myAL.Capacity)
        Console.Write("   Values:")
        PrintValues(myAL)
    End Sub

    Public Shared Sub PrintValues(myList As IEnumerable)
        Dim obj As [Object]
        For Each obj In  myList
            Console.Write("   {0}", obj)
        Next obj
        Console.WriteLine()
    End Sub 'PrintValues

End Class

' This code produces the following output.
' 
' Initially,
'    Count    : 5
'    Capacity : 16
'    Values:    The    quick    brown    fox    jumped
' After TrimToSize,
'    Count    : 5
'    Capacity : 5
'    Values:    The    quick    brown    fox    jumped
' After Clear,
'    Count    : 0
'    Capacity : 5
'    Values:
' After the second TrimToSize,
'    Count    : 0
'    Capacity : 16
'    Values:

using System;
using System.Collections;
public class SamplesArrayList  {

   public static void Main()  {

      // Creates and initializes a new ArrayList.
      ArrayList myAL = new ArrayList();
      myAL.Add( "The" );
      myAL.Add( "quick" );
      myAL.Add( "brown" );
      myAL.Add( "fox" );
      myAL.Add( "jumped" );

      // Displays the count, capacity and values of the ArrayList.
      Console.WriteLine( "Initially," );
      Console.WriteLine( "   Count    : {0}", myAL.Count );
      Console.WriteLine( "   Capacity : {0}", myAL.Capacity );
      Console.Write( "   Values:" );
      PrintValues( myAL );

      // Trim the ArrayList.
      myAL.TrimToSize();

      // Displays the count, capacity and values of the ArrayList.
      Console.WriteLine( "After TrimToSize," );
      Console.WriteLine( "   Count    : {0}", myAL.Count );
      Console.WriteLine( "   Capacity : {0}", myAL.Capacity );
      Console.Write( "   Values:" );
      PrintValues( myAL );

      // Clear the ArrayList.
      myAL.Clear();

      // Displays the count, capacity and values of the ArrayList.
      Console.WriteLine( "After Clear," );
      Console.WriteLine( "   Count    : {0}", myAL.Count );
      Console.WriteLine( "   Capacity : {0}", myAL.Capacity );
      Console.Write( "   Values:" );
      PrintValues( myAL );

      // Trim the ArrayList again.
      myAL.TrimToSize();

      // Displays the count, capacity and values of the ArrayList.
      Console.WriteLine( "After the second TrimToSize," );
      Console.WriteLine( "   Count    : {0}", myAL.Count );
      Console.WriteLine( "   Capacity : {0}", myAL.Capacity );
      Console.Write( "   Values:" );
      PrintValues( myAL );
   }

   public static void PrintValues( IEnumerable myList )  {
      foreach ( Object obj in myList )
         Console.Write( "   {0}", obj );
      Console.WriteLine();
   }

}
/* 
This code produces the following output.

Initially,
   Count    : 5
   Capacity : 16
   Values:    The    quick    brown    fox    jumped
After TrimToSize,
   Count    : 5
   Capacity : 5
   Values:    The    quick    brown    fox    jumped
After Clear,
   Count    : 0
   Capacity : 5
   Values:
After the second TrimToSize,
   Count    : 0
   Capacity : 16
   Values:
*/ 

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList );
int main()
{
   
   // Creates and initializes a new ArrayList.
   ArrayList^ myAL = gcnew ArrayList;
   myAL->Add( "The" );
   myAL->Add( "quick" );
   myAL->Add( "brown" );
   myAL->Add( "fox" );
   myAL->Add( "jumped" );
   
   // Displays the count, capacity and values of the ArrayList.
   Console::WriteLine( "Initially," );
   Console::WriteLine( "   Count    : {0}", myAL->Count );
   Console::WriteLine( "   Capacity : {0}", myAL->Capacity );
   Console::Write( "   Values:" );
   PrintValues( myAL );
   
   // Trim the ArrayList.
   myAL->TrimToSize();
   
   // Displays the count, capacity and values of the ArrayList.
   Console::WriteLine( "After TrimToSize," );
   Console::WriteLine( "   Count    : {0}", myAL->Count );
   Console::WriteLine( "   Capacity : {0}", myAL->Capacity );
   Console::Write( "   Values:" );
   PrintValues( myAL );
   
   // Clear the ArrayList.
   myAL->Clear();
   
   // Displays the count, capacity and values of the ArrayList.
   Console::WriteLine( "After Clear," );
   Console::WriteLine( "   Count    : {0}", myAL->Count );
   Console::WriteLine( "   Capacity : {0}", myAL->Capacity );
   Console::Write( "   Values:" );
   PrintValues( myAL );
   
   // Trim the ArrayList again.
   myAL->TrimToSize();
   
   // Displays the count, capacity and values of the ArrayList.
   Console::WriteLine( "After the second TrimToSize," );
   Console::WriteLine( "   Count    : {0}", myAL->Count );
   Console::WriteLine( "   Capacity : {0}", myAL->Capacity );
   Console::Write( "   Values:" );
   PrintValues( myAL );
}

void PrintValues( IEnumerable^ myList )
{
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::Write( "   {0}", obj );
   }

   Console::WriteLine();
}

/* 
 This code produces the following output.
 
 Initially,
    Count    : 5
    Capacity : 16
    Values:    The    quick    brown    fox    jumped
 After TrimToSize,
    Count    : 5
    Capacity : 5
    Values:    The    quick    brown    fox    jumped
 After Clear,
    Count    : 0
    Capacity : 5
    Values:
 After the second TrimToSize,
    Count    : 0
    Capacity : 16
    Values:
 */

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

public class SamplesArrayList
{
    public static void main(String[] args)
    {
        // Creates and initializes a new ArrayList.
        ArrayList myAL = new ArrayList();

        myAL.Add("The");
        myAL.Add("quick");
        myAL.Add("brown");
        myAL.Add("fox");
        myAL.Add("jumped");

        // Displays the count, capacity and values of the ArrayList.
        Console.WriteLine("Initially,");
        Console.WriteLine("   Count    : {0}", (Int32)myAL.get_Count());
        Console.WriteLine("   Capacity : {0}", (Int32)myAL.get_Capacity());
        Console.Write("   Values:");
        PrintValues(myAL);

        // Trim the ArrayList.
        myAL.TrimToSize();

        // Displays the count, capacity and values of the ArrayList.
        Console.WriteLine("After TrimToSize,");
        Console.WriteLine("   Count    : {0}", (Int32)myAL.get_Count());
        Console.WriteLine("   Capacity : {0}", (Int32)myAL.get_Capacity());
        Console.Write("   Values:");
        PrintValues(myAL);

        // Clear the ArrayList.
        myAL.Clear();

        // Displays the count, capacity and values of the ArrayList.
        Console.WriteLine("After Clear,");
        Console.WriteLine("   Count    : {0}", (Int32)myAL.get_Count());
        Console.WriteLine("   Capacity : {0}", (Int32)myAL.get_Capacity());
        Console.Write("   Values:");
        PrintValues(myAL);

        // Trim the ArrayList again.
        myAL.TrimToSize();

        // Displays the count, capacity and values of the ArrayList.
        Console.WriteLine("After the second TrimToSize,");
        Console.WriteLine("   Count    : {0}", (Int32)myAL.get_Count());
        Console.WriteLine("   Capacity : {0}", (Int32)myAL.get_Capacity());
        Console.Write("   Values:");
        PrintValues(myAL);
    } //main

    public static void PrintValues(IEnumerable myList)
    {
        IEnumerator objMyEnum = myList.GetEnumerator();
        while (objMyEnum.MoveNext()) {
            Object obj = objMyEnum.get_Current();
            Console.Write("   {0}", obj);
        }
        Console.WriteLine();
    } //PrintValues
} //SamplesArrayList 
/* 
 This code produces the following output.
 
 Initially,
    Count    : 5
    Capacity : 16
    Values:    The    quick    brown    fox    jumped
 After TrimToSize,
    Count    : 5
    Capacity : 5
    Values:    The    quick    brown    fox    jumped
 After Clear,
    Count    : 0
    Capacity : 5
    Values:
 After the second TrimToSize,
    Count    : 0
    Capacity : 16
    Values:
 */

import System;
import System.Collections;


// Creates and initializes a new ArrayList.
var myAL : ArrayList = new ArrayList();
myAL.Add( "The" );
myAL.Add( "quick" );
myAL.Add( "brown" );
myAL.Add( "fox" );
myAL.Add( "jumped" );

// Displays the count, capacity and values of the ArrayList.
Console.WriteLine( "Initially," );
Console.WriteLine( "   Count    : {0}", myAL.Count );
Console.WriteLine( "   Capacity : {0}", myAL.Capacity );
Console.Write( "   Values:" );
PrintValues( myAL );

// Trim the ArrayList.
myAL.TrimToSize();

// Displays the count, capacity and values of the ArrayList.
Console.WriteLine( "After TrimToSize," );
Console.WriteLine( "   Count    : {0}", myAL.Count );
Console.WriteLine( "   Capacity : {0}", myAL.Capacity );
Console.Write( "   Values:" );
PrintValues( myAL );

// Clear the ArrayList.
myAL.Clear();

// Displays the count, capacity and values of the ArrayList.
Console.WriteLine( "After Clear," );
Console.WriteLine( "   Count    : {0}", myAL.Count );
Console.WriteLine( "   Capacity : {0}", myAL.Capacity );
Console.Write( "   Values:" );
PrintValues( myAL );

// Trim the ArrayList again.
myAL.TrimToSize();

// Displays the count, capacity and values of the ArrayList.
Console.WriteLine( "After the second TrimToSize," );
Console.WriteLine( "   Count    : {0}", myAL.Count );
Console.WriteLine( "   Capacity : {0}", myAL.Capacity );
Console.Write( "   Values:" );
PrintValues( myAL );
 
function PrintValues( myList : IEnumerable)  {
   var myEnumerator : System.Collections.IEnumerator  = myList.GetEnumerator();
   while ( myEnumerator.MoveNext() )
      Console.Write( "\t{0}", myEnumerator.Current );
   Console.WriteLine();
}
 /* 
 This code produces the following output.
 
 Initially,
    Count    : 5
    Capacity : 16
    Values:    The    quick    brown    fox    jumped
 After TrimToSize,
    Count    : 5
    Capacity : 5
    Values:    The    quick    brown    fox    jumped
 After Clear,
    Count    : 0
    Capacity : 5
    Values:
 After the second TrimToSize,
    Count    : 0
    Capacity : 16
    Values:
 */ 

플랫폼

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

.NET Framework에서 모든 플래폼의 모든 버전을 지원하지는 않습니다. 지원되는 버전의 목록은 시스템 요구 사항을 참조하십시오.

버전 정보

.NET Framework

2.0, 1.1, 1.0에서 지원

.NET Compact Framework

2.0, 1.0에서 지원

참고 항목

참조

ArrayList 클래스
ArrayList 멤버
System.Collections 네임스페이스
Clear
Capacity
Count