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List<T>::CopyTo Method (Int32, array<T>, Int32, Int32)

Copies a range of elements from the List<T> to a compatible one-dimensional array, starting at the specified index of the target array.

Namespace:  System.Collections.Generic
Assembly:  mscorlib (in mscorlib.dll)

public:
void CopyTo(
	int index, 
	array<T>^ array, 
	int arrayIndex, 
	int count
)

Parameters

index
Type: System::Int32

The zero-based index in the source List<T> at which copying begins.

array
Type: array<T>

The one-dimensional Array that is the destination of the elements copied from List<T>. The Array must have zero-based indexing.

arrayIndex
Type: System::Int32

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

count
Type: System::Int32

The number of elements to copy.

ExceptionCondition
ArgumentNullException

array is nullptr.

ArgumentOutOfRangeException

index is less than 0.

-or-

arrayIndex is less than 0.

-or-

count is less than 0.

ArgumentException

index is equal to or greater than the Count of the source List<T>.

-or-

The number of elements from index to the end of the source List<T> is greater than the available space from arrayIndex to the end of the destination array.

This method uses Array::Copy to copy the elements.

The elements are copied to the Array in the same order in which the enumerator iterates through the List<T>.

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

The following code example demonstrates all three overloads of the CopyTo method. A List<T> of strings is created and populated with 5 strings. An empty string array of 15 elements is created, and the CopyTo(array<T>) method overload is used to copy all the elements of the list to the array beginning at the first element of the array. The CopyTo(array<T>, Int32) method overload is used to copy all the elements of the list to the array beginning at array index 6 (leaving index 5 empty). Finally, the CopyTo(Int32, array<T>, Int32, Int32) method overload is used to copy 3 elements from the list, beginning with index 2, to the array beginning at array index 12 (leaving index 11 empty). The contents of the array are then displayed.

using namespace System;
using namespace System::Collections::Generic;

void main()
{
    List<String^>^ dinosaurs = gcnew List<String^>();

    dinosaurs->Add("Tyrannosaurus");
    dinosaurs->Add("Amargasaurus");
    dinosaurs->Add("Mamenchisaurus");
    dinosaurs->Add("Brachiosaurus");
    dinosaurs->Add("Compsognathus");

    Console::WriteLine();
    for each(String^ dinosaurs in dinosaurs )
    {
        Console::WriteLine(dinosaurs);
    }

    // Create an array of 15 strings. 
    array<String^>^ arr = gcnew array<String^>(15);

    dinosaurs->CopyTo(arr);
    dinosaurs->CopyTo(arr, 6);
    dinosaurs->CopyTo(2, arr, 12, 3);

    Console::WriteLine("\nContents of the array:");
    for each(String^ dinosaurs in arr )
    {
        Console::WriteLine(dinosaurs);
    }
}

/* This code example produces the following output:

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Brachiosaurus
Deinonychus
Tyrannosaurus
Compsognathus

IndexOf("Tyrannosaurus"): 0

IndexOf("Tyrannosaurus", 3): 5

IndexOf("Tyrannosaurus", 2, 2): -1
 */

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

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