| Description |
The CopyTo method takes all elements from the current Queue and overlays these values onto elements of the TargetArray.
The overlay starts at the TargetIndex value.
Important : the TargetArray must be created in advance - the CopyTo method overlays - it does not build. Also, the target array must have at least the same capacity as the number of elements being overlaid (copied).
Important : the TargetArray data type must be able to accomodate the Queue data types in the copy process. If the CopyTo method cannot cast to the target array, then an exception is thrown.
Just like Clone, CopyTo performs a shallow copy. When the current Queue holds reference (non primitive) data types, the target array element values still refer to the same objects that current queue elements refer to. This is what is referred to as a shallow copy. A deep copy would create new versions of the referred objects.
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| Microsoft MSDN Links |
System.Collections
System.Collections.Queue
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| Copying the whole Queue onto the middle of an Array |
// Full Unit code.
// -------------------------------------------------------------
// Create a new WinForm application, double click the form to
// create an OnLoad event, and then replace the WinForm unit
// with this text.
unit WinForm;
interface
uses
System.Drawing, System.Collections, System.ComponentModel,
System.Windows.Forms, System.Data;
type
TWinForm = class(System.Windows.Forms.Form)
\{REGION 'Designer Managed Code'\} // Note that REGION and ENREGION should be prefixed by a dollar sign
strict private
///
/// Required designer variable.
///
Components: System.ComponentModel.Container;
///
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
///
procedure InitializeComponent;
procedure TWinForm_Load(sender: System.Object; e: System.EventArgs);
{ENDREGION}
strict protected
///
/// Clean up any resources being used.
///
procedure Dispose(Disposing: Boolean); override;
private
{ Private Declarations }
public
constructor Create;
end;
[assembly: RuntimeRequiredAttribute(TypeOf(TWinForm))]
implementation
\{REGION 'Windows Form Designer generated code'\}
///
/// Required method for Designer support -- do not modify
/// the contents of this method with the code editor.
///
procedure TWinForm.InitializeComponent;
begin
//
// TWinForm
//
Self.AutoScaleBaseSize := System.Drawing.Size.Create(5, 13);
Self.ClientSize := System.Drawing.Size.Create(292, 266);
Self.Name := 'TWinForm';
Self.Text := 'WinForm';
Include(Self.Load, Self.TWinForm_Load);
end;
{ENDREGION}
procedure TWinForm.Dispose(Disposing: Boolean);
begin
if Disposing then
begin
if Components <> nil then
Components.Dispose();
end;
inherited Dispose(Disposing);
end;
constructor TWinForm.Create;
begin
inherited Create;
//
// Required for Windows Form Designer support
//
InitializeComponent;
//
// TODO: Add any constructor code after InitializeComponent call
//
end;
procedure TWinForm.TWinForm_Load(sender: System.Object; e: System.EventArgs);
program Project1;
{$APPTYPE CONSOLE}
uses
System.Collections;
var
MyQueue : System.Collections.Queue;
MyArray : System.Array;
i : Integer;
begin
// Create our queue
MyQueue := Queue.Create;
// Add entries to the queue
MyQueue.EnQueue('First');
MyQueue.EnQueue('Second');
MyQueue.Enqueue('Third');
// Create the target array
MyArray := System.Array.CreateInstance(TypeOf(String), 7);
// And fill it
MyArray.SetValue('0.', 0);
MyArray.SetValue('1.', 1);
MyArray.SetValue('2.', 2);
MyArray.SetValue('3.', 3);
MyArray.SetValue('4.', 4);
MyArray.SetValue('5.', 5);
MyArray.SetValue('6.', 6);
// Copy the queue to the middle of the array
MyQueue.CopyTo(MyArray, 2);
// Display the array
Console.WriteLine('MyArray now holds :');
Console.WriteLine;
for i := 0 to MyArray.Length-1 do
Console.WriteLine(MyArray.GetValue(i).toString);
Console.Readline;
end.
end. | | Hide full unit code | MyArray now holds :
0.
1.
First
Second
Third
5.
6.
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