ArrayList.ToArray 方法

定義

ArrayList 的項目複製到新的陣列。Copies the elements of the ArrayList to a new array.

多載

ToArray()

ArrayList 的項目複製到新的 Object 陣列。Copies the elements of the ArrayList to a new Object array.

ToArray(Type)

ArrayList 的項目複製到指定項目類型的新陣列。Copies the elements of the ArrayList to a new array of the specified element type.

ToArray()

ArrayList 的項目複製到新的 Object 陣列。Copies the elements of the ArrayList to a new Object array.

public:
 virtual cli::array <System::Object ^> ^ ToArray();
public virtual object[] ToArray ();
abstract member ToArray : unit -> obj[]
override this.ToArray : unit -> obj[]
Public Overridable Function ToArray () As Object()

傳回

Object[]

含有 Object 的項目複本的 ArrayList 陣列。An Object array containing copies of the elements of the ArrayList.

備註

專案會使用 Array.Copy來複製,這是 O(n) 作業,其中 nCountThe elements are copied using Array.Copy, which is an O(n) operation, where n is Count.

ToArray(Type)

ArrayList 的項目複製到指定項目類型的新陣列。Copies the elements of the ArrayList to a new array of the specified element type.

public:
 virtual Array ^ ToArray(Type ^ type);
public virtual Array ToArray (Type type);
abstract member ToArray : Type -> Array
override this.ToArray : Type -> Array

參數

type
Type

要建立及複製項目之目的端陣列的項目 TypeThe element Type of the destination array to create and copy elements to.

傳回

由指定項目類型組成且含有 ArrayList 項目複本的陣列。An array of the specified element type containing copies of the elements of the ArrayList.

例外狀況

typenulltype is null.

來源 ArrayList 類型無法自動轉換成指定的類型。The type of the source ArrayList cannot be cast automatically to the specified type.

範例

下列複製範例顯示如何將 ArrayList 的元素複製到字串陣列。The following copy example shows how to copy the elements of an ArrayList to a string array.

using namespace System;
using namespace System::Collections;
void PrintIndexAndValues( ArrayList^ myList );
void PrintIndexAndValues( array<String^>^myArr );
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" );

   // Displays the values of the ArrayList.
   Console::WriteLine( "The ArrayList contains the following values:" );
   PrintIndexAndValues( myAL );

   // Copies the elements of the ArrayList to a string array.
   array<String^>^myArr = reinterpret_cast<array<String^>^>(myAL->ToArray( String::typeid ));

   // Displays the contents of the string array.
   Console::WriteLine( "The string array contains the following values:" );
   PrintIndexAndValues( myArr );
}

void PrintIndexAndValues( ArrayList^ myList )
{
   int i = 0;
   IEnumerator^ myEnum = myList->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Object^ o = safe_cast<Object^>(myEnum->Current);
      Console::WriteLine( "\t[{0}]:\t{1}", i++, o );
   }

   Console::WriteLine();
}

void PrintIndexAndValues( array<String^>^myArr )
{
   for ( int i = 0; i < myArr->Length; i++ )
      Console::WriteLine( "\t[{0}]:\t{1}", i, myArr[ i ] );
   Console::WriteLine();
}

/* 
This code produces the following output.

The ArrayList contains the following values:
        [0]:    The
        [1]:    quick
        [2]:    brown
        [3]:    fox
        [4]:    jumps
        [5]:    over
        [6]:    the
        [7]:    lazy
        [8]:    dog

The string array contains the following values:
        [0]:    The
        [1]:    quick
        [2]:    brown
        [3]:    fox
        [4]:    jumps
        [5]:    over
        [6]:    the
        [7]:    lazy
        [8]:    dog

*/
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" );
 
      // Displays the values of the ArrayList.
      Console.WriteLine( "The ArrayList contains the following values:" );
      PrintIndexAndValues( myAL );
 
      // Copies the elements of the ArrayList to a string array.
      String[] myArr = (String[]) myAL.ToArray( typeof( string ) );

      // Displays the contents of the string array.
      Console.WriteLine( "The string array contains the following values:" );
      PrintIndexAndValues( myArr );
   }
 
   public static void PrintIndexAndValues( ArrayList myList )  {
      int i = 0;
      foreach ( Object o in myList )
         Console.WriteLine( "\t[{0}]:\t{1}", i++, o );
      Console.WriteLine();
   }

   public static void PrintIndexAndValues( String[] myArr )  {
      for ( int i = 0; i < myArr.Length; i++ )
         Console.WriteLine( "\t[{0}]:\t{1}", i, myArr[i] );
      Console.WriteLine();
   }
}


/* 
This code produces the following output.

The ArrayList contains the following values:
        [0]:    The
        [1]:    quick
        [2]:    brown
        [3]:    fox
        [4]:    jumps
        [5]:    over
        [6]:    the
        [7]:    lazy
        [8]:    dog

The string array contains the following values:
        [0]:    The
        [1]:    quick
        [2]:    brown
        [3]:    fox
        [4]:    jumps
        [5]:    over
        [6]:    the
        [7]:    lazy
        [8]:    dog

*/

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")

        ' Displays the values of the ArrayList.
        Console.WriteLine("The ArrayList contains the following values:")
        PrintIndexAndValues(myAL)

        ' Copies the elements of the ArrayList to a string array.
        Dim myArr As String() = CType(myAL.ToArray(GetType(String)), String())

        ' Displays the contents of the string array.
        Console.WriteLine("The string array contains the following values:")
        PrintIndexAndValues(myArr)

    End Sub

    Overloads Public Shared Sub PrintIndexAndValues(myList As ArrayList)
        Dim i As Integer = 0
        Dim o As [Object]
        For Each o In  myList
            Console.WriteLine("        [{0}]:    {1}", i, o)
            i = i + 1
        Next o
        Console.WriteLine()
    End Sub

    Overloads Public Shared Sub PrintIndexAndValues(myArr() As String)
        Dim i As Integer
        For i = 0 To myArr.Length - 1
            Console.WriteLine("        [{0}]:    {1}", i, myArr(i))
        Next i
        Console.WriteLine()
    End Sub

End Class


'This code produces the following output.
'
'The ArrayList contains the following values:
'        [0]:    The
'        [1]:    quick
'        [2]:    brown
'        [3]:    fox
'        [4]:    jumps
'        [5]:    over
'        [6]:    the
'        [7]:    lazy
'        [8]:    dog
'
'The string array contains the following values:
'        [0]:    The
'        [1]:    quick
'        [2]:    brown
'        [3]:    fox
'        [4]:    jumps
'        [5]:    over
'        [6]:    the
'        [7]:    lazy
'        [8]:    dog

備註

ArrayList 物件中的所有物件都會轉換成 type 參數中指定的 TypeAll of the objects in the ArrayList object will be cast to the Type specified in the type parameter.

專案會使用 Array.Copy來複製,這是 O(n) 作業,其中 nCountThe elements are copied using Array.Copy, which is an O(n) operation, where n is Count.

另請參閱

適用於