Array 類

 

Array 類

 

提供創建、操作、搜索和排序數組的方法，因而在公共語言運行庫中用作所有數組的基類。

命名空間：   System
程序集：  mscorlib（在 mscorlib.dll 中）

 語法

Visual Basic（聲明）

<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public MustInherit Class Array _
    Implements ICloneable, IList, ICollection, IEnumerable

Visual Basic (用法)

Dim instance As Array

C#

[SerializableAttribute]
[ComVisibleAttribute(true)]
public abstract class Array : ICloneable, 
    IList, ICollection, IEnumerable

Visual C++

[SerializableAttribute]
[ComVisibleAttribute(true)]
public ref class Array abstract : ICloneable, 
    IList, ICollection, IEnumerable

J#

/** @attribute SerializableAttribute */ 
/** @attribute ComVisibleAttribute(true) */
public abstract class Array implements ICloneable, 
    IList, ICollection, IEnumerable

JScript

public abstract class Array implements ICloneable, IList, ICollection, IEnumerable

 備註

Array 類是支持數組的語言實現的基類。但是，只有系統和編譯器能夠從 Array 類顯式派生。用戶應當使用由語言提供的數組構造。

一個元素就是 Array 中的一個值。Array 的長度是它可包含的元素總數。Array 的秩是 Array 中的維數。Array 中維度的下限是 Array 中該維度的起始索引，多維 Array 的各個維度可以有不同的界限。

重要說明：

在 .NET Framework 2.0 版中，Array 類實現 System.Collections.Generic..::.IList<(Of <(T>)>) 、System.Collections.Generic..::.ICollection<(Of <(T>)>) 和 System.Collections.Generic..::.IEnumerable<(Of <(T>)>) 泛型接口。由於實現是在運行時提供給數組的，因而對於文檔生成工具不可見。因此，泛型接口不會出現在 Array 類的聲明語法中，也不會有關於只能通過將數組強制轉換爲泛型接口類型（顯式接口實現）纔可訪問的接口成員的參考主題。將某一數組強制轉換爲這三種接口之一時需要注意的關鍵一點是，添加、插入或移除元素的成員會引發 NotSupportedException。

Type 對象提供有關數組類型聲明的信息。具有相同數組類型的 Array 對象共享同一 Type 對象。

Type..::.IsArray 和 Type..::.GetElementType 可能不返回所預期的 Array 形式的結果，因爲如果某個數組被強制轉換爲 Array 類型，則結果是對象，而非數組。即，typeof(System.Array).IsArray 返回 false，而 typeof(System.Array).GetElementType 返回 nullNothingnullptrnull 引用（在 Visual Basic 中爲 Nothing）。

與大多數類不同，Array 提供 CreateInstance 方法，以便允許後期綁定訪問，而不是提供公共構造函數。

Array..::.Copy 方法不僅可在同一類型的數組之間複製元素，而且可在不同類型的標準數組之間複製元素；它會自動處理強制類型轉換。

有些方法，如 CreateInstance、 Copy、 CopyTo、 GetValue 和 SetValue，提供重載（接受 64 位整數作爲參數），以適應大容量數組。 LongLength 和 GetLongLength 返回指示數組長度的 64 位整數。

不保證會對 Array 進行排序。 在執行需要對 Array 進行排序的操作（如 BinarySearch）之前，必須對 Array 進行排序。

 示例

下面的代碼示例說明 Array..::.Copy 如何在 integer 類型的數組和 Object 類型的數組之間複製元素。

Visual Basic

複製代碼

Public Class SamplesArray    

    Public Shared Sub Main()

        ' Creates and initializes a new integer array and a new Object array.
        Dim myIntArray() As Integer = {1, 2, 3, 4, 5}
        Dim myObjArray() As Object = {26, 27, 28, 29, 30}

        ' Prints the initial values of both arrays.
        Console.WriteLine("Initially,")
        Console.Write("integer array:")
        PrintValues(myIntArray)
        Console.Write("Object array: ")
        PrintValues(myObjArray)

        ' Copies the first two elements from the integer array to the Object array.
        System.Array.Copy(myIntArray, myObjArray, 2)

        ' Prints the values of the modified arrays.
        Console.WriteLine(ControlChars.NewLine + "After copying the first two" _
           + " elements of the integer array to the Object array,")
        Console.Write("integer array:")
        PrintValues(myIntArray)
        Console.Write("Object array: ")
        PrintValues(myObjArray)

        ' Copies the last two elements from the Object array to the integer array.
        System.Array.Copy(myObjArray, myObjArray.GetUpperBound(0) - 1, myIntArray, _
           myIntArray.GetUpperBound(0) - 1, 2)

        ' Prints the values of the modified arrays.
        Console.WriteLine(ControlChars.NewLine + "After copying the last two" _
           + " elements of the Object array to the integer array,")
        Console.Write("integer array:")
        PrintValues(myIntArray)
        Console.Write("Object array: ")
        PrintValues(myObjArray)
    End Sub

    Overloads Public Shared Sub PrintValues(myArr() As Object)
        Dim i As Object
        For Each i In  myArr
            Console.Write(ControlChars.Tab + "{0}", i)
        Next i
        Console.WriteLine()
    End Sub    

    Overloads Public Shared Sub PrintValues(myArr() As Integer)
        Dim i As Integer
        For Each i In  myArr
            Console.Write(ControlChars.Tab + "{0}", i)
        Next i
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' Initially,
' integer array:  1       2       3       4       5
' Object array:   26      27      28      29      30
' 
' After copying the first two elements of the integer array to the Object array,
' integer array:  1       2       3       4       5
' Object array:   1       2       28      29      30
' 
' After copying the last two elements of the Object array to the integer array,
' integer array:  1       2       3       29      30
' Object array:   1       2       28      29      30

C#

複製代碼

public class SamplesArray  {

   public static void Main()  {

      // Creates and initializes a new integer array and a new Object array.
      int[] myIntArray = new int[5] { 1, 2, 3, 4, 5 };
      Object[] myObjArray = new Object[5] { 26, 27, 28, 29, 30 };

      // Prints the initial values of both arrays.
      Console.WriteLine( "Initially," );
      Console.Write( "integer array:" );
      PrintValues( myIntArray );
      Console.Write( "Object array: " );
      PrintValues( myObjArray );

      // Copies the first two elements from the integer array to the Object array.
      System.Array.Copy( myIntArray, myObjArray, 2 );

      // Prints the values of the modified arrays.
      Console.WriteLine( "/nAfter copying the first two elements of the integer array to the Object array," );
      Console.Write( "integer array:" );
      PrintValues( myIntArray );
      Console.Write( "Object array: " );
      PrintValues( myObjArray );

      // Copies the last two elements from the Object array to the integer array.
      System.Array.Copy( myObjArray, myObjArray.GetUpperBound(0) - 1, myIntArray, myIntArray.GetUpperBound(0) - 1, 2 );

      // Prints the values of the modified arrays.
      Console.WriteLine( "/nAfter copying the last two elements of the Object array to the integer array," );
      Console.Write( "integer array:" );
      PrintValues( myIntArray );
      Console.Write( "Object array: " );
      PrintValues( myObjArray );
   }


   public static void PrintValues( Object[] myArr )  {
      foreach ( Object i in myArr )  {
         Console.Write( "/t{0}", i );
      }
      Console.WriteLine();
   }

   public static void PrintValues( int[] myArr )  {
      foreach ( int i in myArr )  {
         Console.Write( "/t{0}", i );
      }
      Console.WriteLine();
   }
}
/* 
This code produces the following output.

Initially,
integer array:  1       2       3       4       5
Object array:   26      27      28      29      30

After copying the first two elements of the integer array to the Object array,
integer array:  1       2       3       4       5
Object array:   1       2       28      29      30

After copying the last two elements of the Object array to the integer array,
integer array:  1       2       3       29      30
Object array:   1       2       28      29      30
*/

Visual C++

複製代碼

using namespace System;
void main1();
void main2();
void main()
{
   main1();
   Console::WriteLine();
   main2();
}

void PrintValues( array<Object^>^myArr );
void PrintValues( array<int>^myArr );
void main1()
{
   // Creates and initializes a new int array and a new Object array.
   array<int>^myIntArray = {1,2,3,4,5};
   array<Object^>^myObjArray = {26,27,28,29,30};

   // Prints the initial values of both arrays.
   Console::WriteLine(  "Initially," );
   Console::Write(  "int array:   " );
   PrintValues( myIntArray );
   Console::Write(  "Object array:" );
   PrintValues( myObjArray );

   // Copies the first two elements from the int array to the Object array.
   System::Array::Copy( myIntArray, myObjArray, 2 );

   // Prints the values of the modified arrays.
   Console::WriteLine(  "/nAfter copying the first two elements of the int array to the Object array," );
   Console::Write(  "int array:   " );
   PrintValues( myIntArray );
   Console::Write(  "Object array:" );
   PrintValues( myObjArray );

   // Copies the last two elements from the Object array to the int array.
   System::Array::Copy( myObjArray, myObjArray->GetUpperBound( 0 ) - 1, myIntArray, myIntArray->GetUpperBound( 0 ) - 1, 2 );

   // Prints the values of the modified arrays.
   Console::WriteLine(  "/nAfter copying the last two elements of the Object array to the int array," );
   Console::Write(  "int array:   " );
   PrintValues( myIntArray );
   Console::Write(  "Object array:" );
   PrintValues( myObjArray );
}

void PrintValues( array<Object^>^myArr )
{
   for ( int i = 0; i < myArr->Length; i++ )
   {
      Console::Write(  "/t{0}", myArr[ i ] );

   }
   Console::WriteLine();
}

void PrintValues( array<int>^myArr )
{
   for ( int i = 0; i < myArr->Length; i++ )
   {
      Console::Write(  "/t{0}", myArr[ i ] );

   }
   Console::WriteLine();
}


/* 
 This code produces the following output.

 Initially,
 int array:       1    2    3    4    5
 Object array:    26    27    28    29    30
 After copying the first two elements of the int array to the Object array,
 int array:       1    2    3    4    5
 Object array:    1    2    28    29    30
 After copying the last two elements of the Object array to the int array,
 int array:       1    2    3    29    30
 Object array:    1    2    28    29    30
 */

J#

複製代碼

public class SamplesArray
{
    public static void main(String[] args)
    {
        // Creates and initializes a new integer array and a new Object array.
        int myIntArray[] = new int[] { 1, 2, 3, 4, 5 };
        Object myObjArray[] = new Object[] { (Int32)26, (Int32)27, (Int32)28, 
            (Int32)29, (Int32)30};
        // Prints the initial values of both arrays.
        Console.WriteLine("Initially,");
        Console.Write("integer array:");
        PrintValues(myIntArray);
        Console.Write("Object array: ");
        PrintValues(myObjArray);
        // Copies the first two elements from the integer array to the 
        // Object array.
        System.Array.Copy(myIntArray, myObjArray, 2);
        // Prints the values of the modified arrays.
        Console.WriteLine("/nAfter copying the first two elements of the"
            + " integer array to the Object array,");
        Console.Write("integer array:");
        PrintValues(myIntArray);
        Console.Write("Object array: ");
        PrintValues(myObjArray);
        // Copies the last two elements from the Object array to the
        // integer array.
        System.Array.Copy(myObjArray, myObjArray.GetUpperBound(0) - 1, myIntArray, 
            myIntArray.GetUpperBound(0) - 1, 2);
        // Prints the values of the modified arrays.
        Console.WriteLine("/nAfter copying the last two elements of the Object"
            + " array to the integer array,");
        Console.Write("integer array:");
        PrintValues(myIntArray);
        Console.Write("Object array: ");
        PrintValues(myObjArray);
    } //main

    public static void PrintValues(Object myArr[])
    {
        Object i = null;
        for (int iCtr = 0; iCtr < myArr.get_Length(); iCtr++) {
            i = myArr[iCtr];
            Console.Write("/t{0}", i);
        }
        Console.WriteLine();
    } //PrintValues

    public static void PrintValues(int myArr[])
    { 
        int i = 0;
        for (int iCtr = 0; iCtr < myArr.get_Length(); iCtr++) {
            i = myArr[iCtr];
            Console.Write("/t{0}", (Int32)i);
        }
        Console.WriteLine();
    } //PrintValues
} //SamplesArray

/* 
 This code produces the following output.

 Initially,
 integer array:  1       2       3       4       5
 Object array:   26      27      28      29      30

 After copying the first two elements of the integer array to the Object array,
 integer array:  1       2       3       4       5
 Object array:   1       2       28      29      30

 After copying the last two elements of the Object array to the integer array,
 integer array:  1       2       3       29      30
 Object array:   1       2       28      29      30
 */

下面的代碼示例創建並初始化一個 Array，然後顯示其屬性和元素。

Visual Basic

複製代碼

Public Class SamplesArray2    

    Public Shared Sub Main()

        ' Creates and initializes a new three-dimensional Array of
        ' type Int32.
        Dim myArr As Array = Array.CreateInstance(GetType(Int32), 2, 3, 4)
        Dim i As Integer
        For i = myArr.GetLowerBound(0) To myArr.GetUpperBound(0)
            Dim j As Integer
            For j = myArr.GetLowerBound(1) To myArr.GetUpperBound(1)
                Dim k As Integer
                For k = myArr.GetLowerBound(2) To myArr.GetUpperBound(2)
                    myArr.SetValue(i * 100 + j * 10 + k, i, j, k)
                Next k
            Next j 
        Next i ' Displays the properties of the Array.
        Console.WriteLine("The Array has {0} dimension(s) and a " _
           + "total of {1} elements.", myArr.Rank, myArr.Length)
        Console.WriteLine(ControlChars.Tab + "Length" + ControlChars.Tab _
           + "Lower" + ControlChars.Tab + "Upper")
        For i = 0 To myArr.Rank - 1
            Console.Write("{0}:" + ControlChars.Tab + "{1}", i, _
               myArr.GetLength(i))
            Console.WriteLine(ControlChars.Tab + "{0}" + ControlChars.Tab _
               + "{1}", myArr.GetLowerBound(i), myArr.GetUpperBound(i))
        Next i

        ' Displays the contents of the Array.
        Console.WriteLine("The Array contains the following values:")
        PrintValues(myArr)
    End Sub

    Public Shared Sub PrintValues(myArr As Array)
        Dim myEnumerator As System.Collections.IEnumerator = _
           myArr.GetEnumerator()
        Dim i As Integer = 0
        Dim cols As Integer = myArr.GetLength(myArr.Rank - 1)
        While myEnumerator.MoveNext()
            If i < cols Then
                i += 1
            Else
                Console.WriteLine()
                i = 1
            End If
            Console.Write(ControlChars.Tab + "{0}", myEnumerator.Current)
        End While
        Console.WriteLine()
    End Sub
End Class

' This code produces the following output.
' 
' The Array has 3 dimension(s) and a total of 24 elements.
'     Length    Lower    Upper
' 0:    2    0    1
' 1:    3    0    2
' 2:    4    0    3
' The Array contains the following values:
'     0    1    2    3
'     10    11    12    13
'     20    21    22    23
'     100    101    102    103
'     110    111    112    113
'     120    121    122    123 

C#

複製代碼

public class SamplesArray2{

   public static void Main()  {

      // Creates and initializes a new three-dimensional Array of type Int32.
      Array myArr = Array.CreateInstance( typeof(Int32), 2, 3, 4 );
      for ( int i = myArr.GetLowerBound(0); i <= myArr.GetUpperBound(0); i++ )
         for ( int j = myArr.GetLowerBound(1); j <= myArr.GetUpperBound(1); j++ )
            for ( int k = myArr.GetLowerBound(2); k <= myArr.GetUpperBound(2); k++ )  {
               myArr.SetValue( (i*100)+(j*10)+k, i, j, k );
            }

      // Displays the properties of the Array.
      Console.WriteLine( "The Array has {0} dimension(s) and a total of {1} elements.", myArr.Rank, myArr.Length );
      Console.WriteLine( "/tLength/tLower/tUpper" );
      for ( int i = 0; i < myArr.Rank; i++ )  {
         Console.Write( "{0}:/t{1}", i, myArr.GetLength(i) );
         Console.WriteLine( "/t{0}/t{1}", myArr.GetLowerBound(i), myArr.GetUpperBound(i) );
      }

      // Displays the contents of the Array.
      Console.WriteLine( "The Array contains the following values:" );
      PrintValues( myArr );
   }


   public static void PrintValues( Array myArr )  {
      System.Collections.IEnumerator myEnumerator = myArr.GetEnumerator();
      int i = 0;
      int cols = myArr.GetLength( myArr.Rank - 1 );
      while ( myEnumerator.MoveNext() )  {
         if ( i < cols )  {
            i++;
         } else  {
            Console.WriteLine();
            i = 1;
         }
         Console.Write( "/t{0}", myEnumerator.Current );
      }
      Console.WriteLine();
   }
}
/* 
This code produces the following output.

The Array has 3 dimension(s) and a total of 24 elements.
    Length    Lower    Upper
0:    2    0    1
1:    3    0    2
2:    4    0    3
The Array contains the following values:
    0    1    2    3
    10    11    12    13
    20    21    22    23
    100    101    102    103
    110    111    112    113
    120    121    122    123
*/

Visual C++

複製代碼

void PrintValues( Array^ myArr );
void main2()
{
   // Creates and initializes a new three-dimensional Array instance of type Int32.
   Array^ myArr = Array::CreateInstance( Int32::typeid, 2, 3, 4 );
   for ( int i = myArr->GetLowerBound( 0 ); i <= myArr->GetUpperBound( 0 ); i++ )
   {
      for ( int j = myArr->GetLowerBound( 1 ); j <= myArr->GetUpperBound( 1 ); j++ )
      {
         for ( int k = myArr->GetLowerBound( 2 ); k <= myArr->GetUpperBound( 2 ); k++ )
            myArr->SetValue( (i * 100) + (j * 10) + k, i, j, k );

      }
   }

   // Displays the properties of the Array.
   Console::WriteLine(  "The Array instance has {0} dimension(s) and a total of {1} elements.", myArr->Rank, myArr->Length );
   Console::WriteLine(  "/tLength/tLower/tUpper" );
   for ( int i = 0; i < myArr->Rank; i++ )
   {
      Console::Write(  "{0}:/t{1}", i, myArr->GetLength( i ) );
      Console::WriteLine(  "/t{0}/t{1}", myArr->GetLowerBound( i ), myArr->GetUpperBound( i ) );

   }
   Console::WriteLine(  "The Array instance contains the following values:" );
   PrintValues( myArr );
}

void PrintValues( Array^ myArr )
{
   System::Collections::IEnumerator^ myEnumerator = myArr->GetEnumerator();
   int i = 0;
   int cols = myArr->GetLength( myArr->Rank - 1 );
   while ( myEnumerator->MoveNext() )
   {
      if ( i < cols )
            i++;
      else
      {
         Console::WriteLine();
         i = 1;
      }

      Console::Write(  "/t{0}", myEnumerator->Current );
   }

   Console::WriteLine();
}

/* 
 This code produces the following output.

 The Array instance has 3 dimension(s) and a total of 24 elements.
     Length    Lower    Upper
 0:    2    0    1
 1:    3    0    2
 2:    4    0    3
 The Array instance contains the following values:
     0    1    2    3
     10    11    12    13
     20    21    22    23
     100    101    102    103
     110    111    112    113
     120    121    122    123
 */

J#

複製代碼

public class SamplesArray2
{
    public static void main(String[] args)
    {
        // Creates and initializes a new three-dimensional Array of type Int32.
        Array myArr = Array.CreateInstance(Int32.class.ToType(), 2, 3, 4);
        for (int i = myArr.GetLowerBound(0); i <= myArr.GetUpperBound(0); i++) {
            for (int j = myArr.GetLowerBound(1); j <= myArr.GetUpperBound(1);
                j++) {
                for (int k = myArr.GetLowerBound(2); k <= myArr.
                    GetUpperBound(2); k++) {
                    myArr.SetValue((Int32)(i * 100 + j * 10 + k), i, j, k);
                }
            }
        }  // Displays the properties of the Array.
        Console.WriteLine("The Array has {0} dimension(s) and a total of"
            + " {1} elements.", System.Convert.ToString(myArr.get_Rank()), 
            System.Convert.ToString(myArr.get_Length()));
        Console.WriteLine("/tLength/tLower/tUpper");
        for (int i = 0; i < myArr.get_Rank(); i++) {
            Console.Write("{0}:/t{1}", System.Convert.ToString(i), 
                System.Convert.ToString(myArr.GetLength(i)));
            Console.WriteLine("/t{0}/t{1}", System.Convert.ToString(myArr.
                GetLowerBound(i)), System.Convert.ToString(myArr.
                GetUpperBound(i)));
        }
        // Displays the contents of the Array.
        Console.WriteLine("The Array contains the following values:");
        PrintValues(myArr);
    } //main

    public static void PrintValues(Array myArr)
    {
        System.Collections.IEnumerator myEnumerator = myArr.GetEnumerator();
        int i = 0;
        int cols = myArr.GetLength(myArr.get_Rank() - 1);
        while (myEnumerator.MoveNext()) {
            if (i < cols) {
                i++;
            }
            else {
                Console.WriteLine();
                i = 1;
            }
            Console.Write("/t{0}", myEnumerator.get_Current());
        }
        Console.WriteLine();
    } //PrintValues
} //SamplesArray2

/* 
 This code produces the following output.

 The Array has 3 dimension(s) and a total of 24 elements.
     Length    Lower    Upper
 0:    2    0    1
 1:    3    0    2
 2:    4    0    3
 The Array contains the following values:
     0    1    2    3
     10    11    12    13
     20    21    22    23
     100    101    102    103
     110    111    112    113
     120    121    122    123
 */

 繼承層次結構

System..::.Object
  System..::.Array

 線程安全

此類型的公共靜態（在 Visual Basic 中爲 Shared）成員是線程安全的。但不能保證任何實例成員是線程安全的。

此實現不提供 Array 的同步（線程安全）包裝；但是，基於 Array 的 .NET Framework 類使用 SyncRoot 屬性提供它們自己的集合同步版本。

通過集合枚舉在本質上不是一個線程安全的過程。即使一個集合已進行同步，其他線程仍可以修改該集合，這將導致枚舉數引發異常。若要在枚舉過程中保證線程安全，可以在整個枚舉過程中鎖定集合，或者捕捉由於其他線程進行的更改而引發的異常。