ArrayList.FixedSize 方法

定义

返回具有固定大小的列表包装,其中的元素允许修改,但不允许添加或移除。Returns a list wrapper with a fixed size, where elements are allowed to be modified, but not added or removed.

重载

FixedSize(ArrayList)

返回具有固定大小的 ArrayList 包装。Returns an ArrayList wrapper with a fixed size.

FixedSize(IList)

返回具有固定大小的 IList 包装。Returns an IList wrapper with a fixed size.

FixedSize(ArrayList)

返回具有固定大小的 ArrayList 包装。Returns an ArrayList wrapper with a fixed size.

public:
 static System::Collections::ArrayList ^ FixedSize(System::Collections::ArrayList ^ list);
public static System.Collections.ArrayList FixedSize (System.Collections.ArrayList list);
static member FixedSize : System.Collections.ArrayList -> System.Collections.ArrayList
Public Shared Function FixedSize (list As ArrayList) As ArrayList

参数

list
ArrayList

要包装的 ArrayListThe ArrayList to wrap.

返回

ArrayList

具有固定大小的 ArrayList 包装。An ArrayList wrapper with a fixed size.

例外

listnulllist is null.

示例

下面的代码示例演示如何创建周围固定大小的包装 ArrayListThe following code example shows how to create a fixed-size wrapper around an ArrayList.

using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList, char mySeparator );
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( "jumps" );
   myAL->Add( "over" );
   myAL->Add( "the" );
   myAL->Add( "lazy" );
   myAL->Add( "dog" );
   
   // Create a fixed-size wrapper around the ArrayList.
   ArrayList^ myFixedSizeAL = ArrayList::FixedSize( myAL );
   
   // Display whether the ArrayLists have a fixed size or not.
   Console::WriteLine( "myAL {0}.", myAL->IsFixedSize ? (String^)"has a fixed size" : "does not have a fixed size" );
   Console::WriteLine( "myFixedSizeAL {0}.", myFixedSizeAL->IsFixedSize ? (String^)"has a fixed size" : "does not have a fixed size" );
   Console::WriteLine();
   
   // Display both ArrayLists.
   Console::WriteLine( "Initially," );
   Console::Write( "Standard  :" );
   PrintValues( myAL, ' ' );
   Console::Write( "Fixed size:" );
   PrintValues( myFixedSizeAL, ' ' );
   
   // Sort is allowed in the fixed-size ArrayList.
   myFixedSizeAL->Sort();
   
   // Display both ArrayLists.
   Console::WriteLine( "After Sort," );
   Console::Write( "Standard  :" );
   PrintValues( myAL, ' ' );
   Console::Write( "Fixed size:" );
   PrintValues( myFixedSizeAL, ' ' );
   
   // Reverse is allowed in the fixed-size ArrayList.
   myFixedSizeAL->Reverse();
   
   // Display both ArrayLists.
   Console::WriteLine( "After Reverse," );
   Console::Write( "Standard  :" );
   PrintValues( myAL, ' ' );
   Console::Write( "Fixed size:" );
   PrintValues( myFixedSizeAL, ' ' );
   
   // Add an element to the standard ArrayList.
   myAL->Add( "AddMe" );
   
   // Display both ArrayLists.
   Console::WriteLine( "After adding to the standard ArrayList," );
   Console::Write( "Standard  :" );
   PrintValues( myAL, ' ' );
   Console::Write( "Fixed size:" );
   PrintValues( myFixedSizeAL, ' ' );
   Console::WriteLine();
   
   // Adding or inserting elements to the fixed-size ArrayList throws an exception.
   try
   {
      myFixedSizeAL->Add( "AddMe2" );
   }
   catch ( Exception^ myException ) 
   {
      Console::WriteLine( "Exception: {0}", myException );
   }

   try
   {
      myFixedSizeAL->Insert( 3, "InsertMe" );
   }
   catch ( Exception^ myException ) 
   {
      Console::WriteLine( "Exception: {0}", myException );
   }

}

void PrintValues( IEnumerable^ myList, char mySeparator )
{
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ obj = safe_cast<Object^>(myEnum->Current);
      Console::Write( "{0}{1}", mySeparator, obj );
   }

   Console::WriteLine();
}

/*
 This code produces the following output.
 
 myAL does not have a fixed size.
 myFixedSizeAL has a fixed size.

 Initially,
 Standard  : The quick brown fox jumps over the lazy dog
 Fixed size: The quick brown fox jumps over the lazy dog
 After Sort,
 Standard  : brown dog fox jumps lazy over quick the The
 Fixed size: brown dog fox jumps lazy over quick the The
 After Reverse,
 Standard  : The the quick over lazy jumps fox dog brown
 Fixed size: The the quick over lazy jumps fox dog brown
 After adding to the standard ArrayList,
 Standard  : The the quick over lazy jumps fox dog brown AddMe
 Fixed size: The the quick over lazy jumps fox dog brown AddMe

 Exception: System.NotSupportedException: Collection was of a fixed size.
    at System.Collections.FixedSizeArrayList.Add(Object obj)
    at SamplesArrayList.Main()
 Exception: System.NotSupportedException: Collection was of a fixed size.
    at System.Collections.FixedSizeArrayList.Insert(Int32 index, Object obj)
    at SamplesArrayList.Main()

 */
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( "jumps" );
      myAL.Add( "over" );
      myAL.Add( "the" );
      myAL.Add( "lazy" );
      myAL.Add( "dog" );

      // Create a fixed-size wrapper around the ArrayList.
      ArrayList myFixedSizeAL = ArrayList.FixedSize( myAL );

      // Display whether the ArrayLists have a fixed size or not.
      Console.WriteLine( "myAL {0}.", myAL.IsFixedSize ? "has a fixed size" : "does not have a fixed size" );
      Console.WriteLine( "myFixedSizeAL {0}.", myFixedSizeAL.IsFixedSize ? "has a fixed size" : "does not have a fixed size" );
      Console.WriteLine();

      // Display both ArrayLists.
      Console.WriteLine( "Initially," );
      Console.Write( "Standard  :" );
      PrintValues( myAL, ' ' );
      Console.Write( "Fixed size:" );
      PrintValues( myFixedSizeAL, ' ' );

      // Sort is allowed in the fixed-size ArrayList.
      myFixedSizeAL.Sort();

      // Display both ArrayLists.
      Console.WriteLine( "After Sort," );
      Console.Write( "Standard  :" );
      PrintValues( myAL, ' ' );
      Console.Write( "Fixed size:" );
      PrintValues( myFixedSizeAL, ' ' );

      // Reverse is allowed in the fixed-size ArrayList.
      myFixedSizeAL.Reverse();

      // Display both ArrayLists.
      Console.WriteLine( "After Reverse," );
      Console.Write( "Standard  :" );
      PrintValues( myAL, ' ' );
      Console.Write( "Fixed size:" );
      PrintValues( myFixedSizeAL, ' ' );

      // Add an element to the standard ArrayList.
      myAL.Add( "AddMe" );

      // Display both ArrayLists.
      Console.WriteLine( "After adding to the standard ArrayList," );
      Console.Write( "Standard  :" );
      PrintValues( myAL, ' ' );
      Console.Write( "Fixed size:" );
      PrintValues( myFixedSizeAL, ' ' );
      Console.WriteLine();

      // Adding or inserting elements to the fixed-size ArrayList throws an exception.
      try  {
         myFixedSizeAL.Add( "AddMe2" );
      } catch ( Exception myException )  {
         Console.WriteLine("Exception: " + myException.ToString());
      }
      try  {
         myFixedSizeAL.Insert( 3, "InsertMe" );
      } catch ( Exception myException )  {
         Console.WriteLine("Exception: " + myException.ToString());
      }
   }

   public static void PrintValues( IEnumerable myList, char mySeparator )  {
      foreach ( Object obj in myList )
         Console.Write( "{0}{1}", mySeparator, obj );
      Console.WriteLine();
   }
}
/*
This code produces the following output.

myAL does not have a fixed size.
myFixedSizeAL has a fixed size.

Initially,
Standard  : The quick brown fox jumps over the lazy dog
Fixed size: The quick brown fox jumps over the lazy dog
After Sort,
Standard  : brown dog fox jumps lazy over quick the The
Fixed size: brown dog fox jumps lazy over quick the The
After Reverse,
Standard  : The the quick over lazy jumps fox dog brown
Fixed size: The the quick over lazy jumps fox dog brown
After adding to the standard ArrayList,
Standard  : The the quick over lazy jumps fox dog brown AddMe
Fixed size: The the quick over lazy jumps fox dog brown AddMe

Exception: System.NotSupportedException: Collection was of a fixed size.
   at System.Collections.FixedSizeArrayList.Add(Object obj)
   at SamplesArrayList.Main()
Exception: System.NotSupportedException: Collection was of a fixed size.
   at System.Collections.FixedSizeArrayList.Insert(Int32 index, Object obj)
   at SamplesArrayList.Main()

*/
Imports System.Collections

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("jumps")
        myAL.Add("over")
        myAL.Add("the")
        myAL.Add("lazy")
        myAL.Add("dog")
        
        ' Create a fixed-size wrapper around the ArrayList.
        Dim myFixedSizeAL As ArrayList = ArrayList.FixedSize(myAL)
        
        ' Display whether the ArrayLists have a fixed size or not.
        Dim msg As String
        If myAL.IsFixedSize Then
            msg = "has a fixed size"
        Else
            msg = "does not have a fixed size"
        End If
        Console.WriteLine("myAL {0}.", msg)
        If myFixedSizeAL.IsFixedSize Then
            msg = "has a fixed size"
        Else
            msg = "does not have a fixed size"
        End If
        Console.WriteLine("myFixedSizeAL {0}.", msg)
        Console.WriteLine()
        
        ' Display both ArrayLists.
        Console.WriteLine("Initially,")
        Console.Write("Standard  :")
        PrintValues(myAL, " "c)
        Console.Write("Fixed size:")
        PrintValues(myFixedSizeAL, " "c)
        
        ' Sort is allowed in the fixed-size ArrayList.
        myFixedSizeAL.Sort()
        
        ' Display both ArrayLists.
        Console.WriteLine("After Sort,")
        Console.Write("Standard  :")
        PrintValues(myAL, " "c)
        Console.Write("Fixed size:")
        PrintValues(myFixedSizeAL, " "c)
        
        ' Reverse is allowed in the fixed-size ArrayList.
        myFixedSizeAL.Reverse()
        
        ' Display both ArrayLists.
        Console.WriteLine("After Reverse,")
        Console.Write("Standard  :")
        PrintValues(myAL, " "c)
        Console.Write("Fixed size:")
        PrintValues(myFixedSizeAL, " "c)
        
        ' Add an element to the standard ArrayList.
        myAL.Add("AddMe")
        
        ' Display both ArrayLists.
        Console.WriteLine("After adding to the standard ArrayList,")
        Console.Write("Standard  :")
        PrintValues(myAL, " "c)
        Console.Write("Fixed size:")
        PrintValues(myFixedSizeAL, " "c)
        Console.WriteLine()
        
        ' Adding or inserting elements to the fixed-size ArrayList throws an exception.
        Try
            myFixedSizeAL.Add("AddMe2")
        Catch myException As Exception
            Console.WriteLine("Exception: " + myException.ToString())
        End Try
        Try
            myFixedSizeAL.Insert(3, "InsertMe")
        Catch myException As Exception
            Console.WriteLine("Exception: " + myException.ToString())
        End Try
    End Sub

    Public Shared Sub PrintValues(myList As IEnumerable, mySeparator As Char)
        Dim obj As [Object]
        For Each obj In  myList
            Console.Write("{0}{1}", mySeparator, obj)
        Next obj
        Console.WriteLine()
    End Sub

End Class


' This code produces the following output.
' 
' myAL does not have a fixed size.
' myFixedSizeAL has a fixed size.
' 
' Initially,
' Standard  : The quick brown fox jumps over the lazy dog
' Fixed size: The quick brown fox jumps over the lazy dog
' After Sort,
' Standard  : brown dog fox jumps lazy over quick the The
' Fixed size: brown dog fox jumps lazy over quick the The
' After Reverse,
' Standard  : The the quick over lazy jumps fox dog brown
' Fixed size: The the quick over lazy jumps fox dog brown
' After adding to the standard ArrayList,
' Standard  : The the quick over lazy jumps fox dog brown AddMe
' Fixed size: The the quick over lazy jumps fox dog brown AddMe
' 
' Exception: System.NotSupportedException: Collection was of a fixed size.
'    at System.Collections.FixedSizeArrayList.Add(Object obj)
'    at SamplesArrayList.Main()
' Exception: System.NotSupportedException: Collection was of a fixed size.
'    at System.Collections.FixedSizeArrayList.Insert(Int32 index, Object obj)
'    at SamplesArrayList.Main()

注解

此包装可用于阻止从原始项中进行添加和删除 ArrayListThis wrapper can be used to prevent additions to and deletions from the original ArrayList. 仍可修改或替换元素。The elements can still be modified or replaced.

具有固定大小的集合就是一个集合,其中包含阻止添加和移除元素的包装;因此,如果对基础集合进行了更改,包括添加或删除元素,则固定大小的集合将反映这些更改。A collection with a fixed size is simply a collection with a wrapper that prevents adding and removing elements; therefore, if changes are made to the underlying collection, including the addition or removal of elements, the fixed-size collection reflects those changes.

此方法是一种 O(1) 操作。This method is an O(1) operation.

适用于

FixedSize(IList)

返回具有固定大小的 IList 包装。Returns an IList wrapper with a fixed size.

public:
 static System::Collections::IList ^ FixedSize(System::Collections::IList ^ list);
public static System.Collections.IList FixedSize (System.Collections.IList list);
static member FixedSize : System.Collections.IList -> System.Collections.IList
Public Shared Function FixedSize (list As IList) As IList

参数

list
IList

要包装的 IListThe IList to wrap.

返回

IList

具有固定大小的 IList 包装。An IList wrapper with a fixed size.

例外

listnulllist is null.

注解

此包装可用于阻止从原始项中进行添加和删除 IListThis wrapper can be used to prevent additions to and deletions from the original IList. 仍可修改或替换元素。The elements can still be modified or replaced.

具有固定大小的集合就是一个集合,其中包含阻止添加和移除元素的包装;因此,如果对基础集合进行了更改,包括添加或删除元素,则固定大小的集合将反映这些更改。A collection with a fixed size is simply a collection with a wrapper that prevents adding and removing elements; therefore, if changes are made to the underlying collection, including the addition or removal of elements, the fixed-size collection reflects those changes.

此方法是一种 O(1) 操作。This method is an O(1) operation.

适用于