Επεξεργασία

Κοινή χρήση μέσω


SortedList.TrimToSize Method

Definition

Sets the capacity to the actual number of elements in a SortedList object.

public:
 virtual void TrimToSize();
public virtual void TrimToSize ();
abstract member TrimToSize : unit -> unit
override this.TrimToSize : unit -> unit
Public Overridable Sub TrimToSize ()

Exceptions

The SortedList object is read-only.

-or-

The SortedList has a fixed size.

Examples

The following code example shows how to trim the unused portions of a SortedList object and how to clear its values.

#using <system.dll>

using namespace System;
using namespace System::Collections;
void PrintKeysAndValues( SortedList^ myList )
{
   Console::WriteLine(  "\t-KEY-\t-VALUE-" );
   for ( int i = 0; i < myList->Count; i++ )
   {
      Console::WriteLine(  "\t{0}:\t{1}", myList->GetKey( i ), myList->GetByIndex( i ) );

   }
   Console::WriteLine();
}

int main()
{
   
   // Creates and initializes a new SortedList.
   SortedList^ mySL = gcnew SortedList;
   mySL->Add( "one", "The" );
   mySL->Add( "two", "quick" );
   mySL->Add( "three", "brown" );
   mySL->Add( "four", "fox" );
   mySL->Add( "five", "jumps" );
   
   // Displays the count, capacity and values of the SortedList.
   Console::WriteLine(  "Initially," );
   Console::WriteLine(  "   Count    : {0}", mySL->Count );
   Console::WriteLine(  "   Capacity : {0}", mySL->Capacity );
   Console::WriteLine(  "   Values:" );
   PrintKeysAndValues( mySL );
   
   // Trims the SortedList.
   mySL->TrimToSize();
   
   // Displays the count, capacity and values of the SortedList.
   Console::WriteLine(  "After TrimToSize," );
   Console::WriteLine(  "   Count    : {0}", mySL->Count );
   Console::WriteLine(  "   Capacity : {0}", mySL->Capacity );
   Console::WriteLine(  "   Values:" );
   PrintKeysAndValues( mySL );
   
   // Clears the SortedList.
   mySL->Clear();
   
   // Displays the count, capacity and values of the SortedList.
   Console::WriteLine(  "After Clear," );
   Console::WriteLine(  "   Count    : {0}", mySL->Count );
   Console::WriteLine(  "   Capacity : {0}", mySL->Capacity );
   Console::WriteLine(  "   Values:" );
   PrintKeysAndValues( mySL );
   
   // Trims the SortedList again.
   mySL->TrimToSize();
   
   // Displays the count, capacity and values of the SortedList.
   Console::WriteLine(  "After the second TrimToSize," );
   Console::WriteLine(  "   Count    : {0}", mySL->Count );
   Console::WriteLine(  "   Capacity : {0}", mySL->Capacity );
   Console::WriteLine(  "   Values:" );
   PrintKeysAndValues( mySL );
}

/* 
This code produces the following output.

Initially,
   Count    : 5
   Capacity : 16
   Values:
        -KEY-   -VALUE-
        five:   jumps
        four:   fox
        one:    The
        three:  brown
        two:    quick

After TrimToSize,
   Count    : 5
   Capacity : 5
   Values:
        -KEY-   -VALUE-
        five:   jumps
        four:   fox
        one:    The
        three:  brown
        two:    quick

After Clear,
   Count    : 0
   Capacity : 16
   Values:
        -KEY-   -VALUE-

After the second TrimToSize,
   Count    : 0
   Capacity : 16
   Values:
        -KEY-   -VALUE-

*/
using System;
using System.Collections;
public class SamplesSortedList  {

   public static void Main()  {

      // Creates and initializes a new SortedList.
      SortedList mySL = new SortedList();
      mySL.Add( "one", "The" );
      mySL.Add( "two", "quick" );
      mySL.Add( "three", "brown" );
      mySL.Add( "four", "fox" );
      mySL.Add( "five", "jumps" );

      // Displays the count, capacity and values of the SortedList.
      Console.WriteLine( "Initially," );
      Console.WriteLine( "   Count    : {0}", mySL.Count );
      Console.WriteLine( "   Capacity : {0}", mySL.Capacity );
      Console.WriteLine( "   Values:" );
      PrintKeysAndValues( mySL );

      // Trims the SortedList.
      mySL.TrimToSize();

      // Displays the count, capacity and values of the SortedList.
      Console.WriteLine( "After TrimToSize," );
      Console.WriteLine( "   Count    : {0}", mySL.Count );
      Console.WriteLine( "   Capacity : {0}", mySL.Capacity );
      Console.WriteLine( "   Values:" );
      PrintKeysAndValues( mySL );

      // Clears the SortedList.
      mySL.Clear();

      // Displays the count, capacity and values of the SortedList.
      Console.WriteLine( "After Clear," );
      Console.WriteLine( "   Count    : {0}", mySL.Count );
      Console.WriteLine( "   Capacity : {0}", mySL.Capacity );
      Console.WriteLine( "   Values:" );
      PrintKeysAndValues( mySL );

      // Trims the SortedList again.
      mySL.TrimToSize();

      // Displays the count, capacity and values of the SortedList.
      Console.WriteLine( "After the second TrimToSize," );
      Console.WriteLine( "   Count    : {0}", mySL.Count );
      Console.WriteLine( "   Capacity : {0}", mySL.Capacity );
      Console.WriteLine( "   Values:" );
      PrintKeysAndValues( mySL );
   }

   public static void PrintKeysAndValues( SortedList myList )  {
      Console.WriteLine( "\t-KEY-\t-VALUE-" );
      for ( int i = 0; i < myList.Count; i++ )  {
         Console.WriteLine( "\t{0}:\t{1}", myList.GetKey(i), myList.GetByIndex(i) );
      }
      Console.WriteLine();
   }
}
/*
This code produces the following output.

Initially,
   Count    : 5
   Capacity : 16
   Values:
    -KEY-    -VALUE-
    five:    jumps
    four:    fox
    one:    The
    three:    brown
    two:    quick

After TrimToSize,
   Count    : 5
   Capacity : 5
   Values:
    -KEY-    -VALUE-
    five:    jumps
    four:    fox
    one:    The
    three:    brown
    two:    quick

After Clear,
   Count    : 0
   Capacity : 16
   Values:
    -KEY-    -VALUE-

After the second TrimToSize,
   Count    : 0
   Capacity : 16
   Values:
    -KEY-    -VALUE-
*/
Imports System.Collections

Public Class SamplesSortedList    
    
    Public Shared Sub Main()
        
        ' Creates and initializes a new SortedList.
        Dim mySL As New SortedList()
        mySL.Add("one", "The")
        mySL.Add("two", "quick")
        mySL.Add("three", "brown")
        mySL.Add("four", "fox")
        mySL.Add("five", "jumps")
        
        ' Displays the count, capacity and values of the SortedList.
        Console.WriteLine("Initially,")
        Console.WriteLine("   Count    : {0}", mySL.Count)
        Console.WriteLine("   Capacity : {0}", mySL.Capacity)
        Console.WriteLine("   Values:")
        PrintKeysAndValues(mySL)
        
        ' Trims the SortedList.
        mySL.TrimToSize()
        
        ' Displays the count, capacity and values of the SortedList.
        Console.WriteLine("After TrimToSize,")
        Console.WriteLine("   Count    : {0}", mySL.Count)
        Console.WriteLine("   Capacity : {0}", mySL.Capacity)
        Console.WriteLine("   Values:")
        PrintKeysAndValues(mySL)
        
        ' Clears the SortedList.
        mySL.Clear()
        
        ' Displays the count, capacity and values of the SortedList.
        Console.WriteLine("After Clear,")
        Console.WriteLine("   Count    : {0}", mySL.Count)
        Console.WriteLine("   Capacity : {0}", mySL.Capacity)
        Console.WriteLine("   Values:")
        PrintKeysAndValues(mySL)
        
        ' Trims the SortedList again.
        mySL.TrimToSize()
        
        ' Displays the count, capacity and values of the SortedList.
        Console.WriteLine("After the second TrimToSize,")
        Console.WriteLine("   Count    : {0}", mySL.Count)
        Console.WriteLine("   Capacity : {0}", mySL.Capacity)
        Console.WriteLine("   Values:")
        PrintKeysAndValues(mySL)
    End Sub   
    
    
    Public Shared Sub PrintKeysAndValues(myList As SortedList)
        Console.WriteLine(ControlChars.Tab & "-KEY-" & ControlChars.Tab & _
           "-VALUE-")
        Dim i As Integer
        For i = 0 To myList.Count - 1
            Console.WriteLine(ControlChars.Tab & "{0}:" & ControlChars.Tab & _
               "{1}", myList.GetKey(i), myList.GetByIndex(i))
        Next i
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' Initially,
'    Count    : 5
'    Capacity : 16
'    Values:
'     -KEY-    -VALUE-
'     five:    jumps
'     four:    fox
'     one:    The
'     three:    brown
'     two:    quick
'
' After TrimToSize,
'    Count    : 5
'    Capacity : 5
'    Values:
'     -KEY-    -VALUE-
'     five:    jumps
'     four:    fox
'     one:    The
'     three:    brown
'     two:    quick
' 
' After Clear,
'    Count    : 0
'    Capacity : 16
'    Values:
'     -KEY-    -VALUE-
' 
'
' After the second TrimToSize,
'    Count    : 0
'    Capacity : 16
'    Values:
'     -KEY-    -VALUE-

Remarks

This method can be used to minimize a collection's memory overhead if no new elements will be added to the collection.

To reset a SortedList object to its initial state, call the Clear method before calling TrimToSize. Trimming an empty SortedList sets the capacity of the SortedList to the default capacity.

This method is an O(n) operation, where n is Count.

Applies to

See also