StringCollection.CopyTo(String[], Int32) 方法

定义

命名空间:

System.Collections.Specialized

程序集:

System.Collections.Specialized.dll

Source:

StringCollection.cs

从目标数组的指定索引处开始，将全部 StringCollection 值复制到一维字符串数组中。

public:
 void CopyTo(cli::array <System::String ^> ^ array, int index);

public void CopyTo (string[] array, int index);

member this.CopyTo : string[] * int -> unit

Public Sub CopyTo (array As String(), index As Integer)

参数

array

String[]

一维字符串数组，用作从 StringCollection 复制元素的目标数组。 Array 必须具有从零开始的索引。

index

Int32

array 中从零开始的索引，从此处开始复制。

例外

ArgumentNullException

array 为 null。

ArgumentOutOfRangeException

index 小于零。

ArgumentException

array 是多维的。

或

源 StringCollection 中的元素个数大于从 index 到目标 array 末尾之间的可用空间。

InvalidCastException

无法自动将源 StringCollection 的类型转换为目标 array 的类型。

示例

下面的代码示例将 复制到 StringCollection 数组。

#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
void PrintValues( IEnumerable^ myCol );
int main()
{
   
   // Creates and initializes a new StringCollection.
   StringCollection^ myCol = gcnew StringCollection;
   array<String^>^myArr = {"RED","orange","yellow","RED","green","blue","RED","indigo","violet","RED"};
   myCol->AddRange( myArr );
   Console::WriteLine( "Initial contents of the StringCollection:" );
   PrintValues( myCol );
   
   // Copies the collection to a new array starting at index 0.
   array<String^>^myArr2 = gcnew array<String^>(myCol->Count);
   myCol->CopyTo( myArr2, 0 );
   Console::WriteLine( "The new array contains:" );
   for ( int i = 0; i < myArr2->Length; i++ )
   {
      Console::WriteLine( "   [{0}] {1}", i, myArr2[ i ] );

   }
   Console::WriteLine();
}

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

   Console::WriteLine();
}

/*
This code produces the following output.

Initial contents of the StringCollection:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

The new array contains:
   [0] RED
   [1] orange
   [2] yellow
   [3] RED
   [4] green
   [5] blue
   [6] RED
   [7] indigo
   [8] violet
   [9] RED

*/

using System;
using System.Collections;
using System.Collections.Specialized;

public class SamplesStringCollection  {

   public static void Main()  {

      // Creates and initializes a new StringCollection.
      StringCollection myCol = new StringCollection();
      String[] myArr = new String[] { "RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED" };
      myCol.AddRange( myArr );

      Console.WriteLine( "Initial contents of the StringCollection:" );
      PrintValues( myCol );

      // Copies the collection to a new array starting at index 0.
      String[] myArr2 = new String[myCol.Count];
      myCol.CopyTo( myArr2, 0 );

      Console.WriteLine( "The new array contains:" );
      for ( int i = 0; i < myArr2.Length; i++ )  {
         Console.WriteLine( "   [{0}] {1}", i, myArr2[i] );
      }
      Console.WriteLine();
   }

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

/*
This code produces the following output.

Initial contents of the StringCollection:
   RED
   orange
   yellow
   RED
   green
   blue
   RED
   indigo
   violet
   RED

The new array contains:
   [0] RED
   [1] orange
   [2] yellow
   [3] RED
   [4] green
   [5] blue
   [6] RED
   [7] indigo
   [8] violet
   [9] RED

*/

Imports System.Collections
Imports System.Collections.Specialized

Public Class SamplesStringCollection   

   Public Shared Sub Main()

      ' Creates and initializes a new StringCollection.
      Dim myCol As New StringCollection()
      Dim myArr() As [String] = {"RED", "orange", "yellow", "RED", "green", "blue", "RED", "indigo", "violet", "RED"}
      myCol.AddRange(myArr)

      Console.WriteLine("Initial contents of the StringCollection:")
      PrintValues(myCol)

      ' Copies the collection to a new array starting at index 0.
      Dim myArr2(myCol.Count) As [String]
      myCol.CopyTo(myArr2, 0)

      Console.WriteLine("The new array contains:")
      Dim i As Integer
      For i = 0 To myArr2.Length - 1
         Console.WriteLine("   [{0}] {1}", i, myArr2(i))
      Next i
      Console.WriteLine()

   End Sub

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

End Class


'This code produces the following output.
'
'Initial contents of the StringCollection:
'   RED
'   orange
'   yellow
'   RED
'   green
'   blue
'   RED
'   indigo
'   violet
'   RED
'
'The new array contains:
'   [0] RED
'   [1] orange
'   [2] yellow
'   [3] RED
'   [4] green
'   [5] blue
'   [6] RED
'   [7] indigo
'   [8] violet
'   [9] RED
'

注解

指定的数组必须属于兼容类型。

元素将按照 的枚举器StringCollection循环访问 的相同顺序复制到 Array 。StringCollection

此方法是 O (n) 操作，其中 n 为 Count。

另请参阅

• Array
• GetEnumerator()