Επεξεργασία

Κοινή χρήση μέσω


StringCollection.CopyTo(String[], Int32) Method

Definition

Copies the entire StringCollection values to a one-dimensional array of strings, starting at the specified index of the target array.

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)

Parameters

array
String[]

The one-dimensional array of strings that is the destination of the elements copied from StringCollection. The Array must have zero-based indexing.

index
Int32

The zero-based index in array at which copying begins.

Exceptions

array is null.

index is less than zero.

array is multidimensional.

-or-

The number of elements in the source StringCollection is greater than the available space from index to the end of the destination array.

The type of the source StringCollection cannot be cast automatically to the type of the destination array.

Examples

The following code example copies a StringCollection to an array.

#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
'

Remarks

The specified array must be of a compatible type.

The elements are copied to the Array in the same order in which the enumerator of the StringCollection iterates through the StringCollection.

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

Applies to

See also