Stack<T>.CopyTo(T[], Int32) 方法
定義
重要
部分資訊涉及發行前產品，在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊，不做任何明確或隱含的瑕疵擔保。
public:
void CopyTo(cli::array <T> ^ array, int arrayIndex);public void CopyTo (T[] array, int arrayIndex);member this.CopyTo : 'T[] * int -> unitPublic Sub CopyTo (array As T(), arrayIndex As Integer)參數
- arrayIndex
- Int32
array 中以零起始的索引，即開始複製的位置。
例外狀況
array 為 null。
arrayIndex 小於零。
來源 Stack<T> 中的項目數大於 arrayIndex 到目的 array 結尾的可用空間。
範例
下列程式代碼範例示範泛型類別的 Stack<T> 數個方法，包括 CopyTo 方法。
此程式代碼範例會建立具有預設容量的字串堆疊，並使用 Push 方法將五個字串推送至堆疊。 會列舉堆疊的專案，而不會變更堆疊的狀態。 方法 Pop 可用來從堆疊取出第一個字串。 方法 Peek 可用來查看堆疊上的下一個專案，然後使用 Pop 方法將其彈出。
方法 ToArray 可用來建立數位，並將堆疊元素複製到其中，然後將數位傳遞至 Stack<T> 採用 IEnumerable<T>的建構函式，並使用反轉元素的順序建立堆疊的複本。 隨即顯示複本的專案。
建立堆疊大小的兩倍陣列，並使用 CopyTo 方法複製陣列元素，從陣列中間開始。 建 Stack<T> 構函式會再次用來建立堆疊的複本，並反轉元素的順序;因此，這三個 Null 元素位於結尾。
方法 Contains 用來顯示字串 「four」 位於堆疊的第一個複本中，之後 Clear 方法會清除複本，而 Count 屬性顯示堆疊是空的。
using System;
using System.Collections.Generic;
class Example
{
public static void Main()
{
Stack<string> numbers = new Stack<string>();
numbers.Push("one");
numbers.Push("two");
numbers.Push("three");
numbers.Push("four");
numbers.Push("five");
// A stack can be enumerated without disturbing its contents.
foreach( string number in numbers )
{
Console.WriteLine(number);
}
Console.WriteLine("\nPopping '{0}'", numbers.Pop());
Console.WriteLine("Peek at next item to destack: {0}",
numbers.Peek());
Console.WriteLine("Popping '{0}'", numbers.Pop());
// Create a copy of the stack, using the ToArray method and the
// constructor that accepts an IEnumerable<T>.
Stack<string> stack2 = new Stack<string>(numbers.ToArray());
Console.WriteLine("\nContents of the first copy:");
foreach( string number in stack2 )
{
Console.WriteLine(number);
}
// Create an array twice the size of the stack and copy the
// elements of the stack, starting at the middle of the
// array.
string[] array2 = new string[numbers.Count * 2];
numbers.CopyTo(array2, numbers.Count);
// Create a second stack, using the constructor that accepts an
// IEnumerable(Of T).
Stack<string> stack3 = new Stack<string>(array2);
Console.WriteLine("\nContents of the second copy, with duplicates and nulls:");
foreach( string number in stack3 )
{
Console.WriteLine(number);
}
Console.WriteLine("\nstack2.Contains(\"four\") = {0}",
stack2.Contains("four"));
Console.WriteLine("\nstack2.Clear()");
stack2.Clear();
Console.WriteLine("\nstack2.Count = {0}", stack2.Count);
}
}
/* This code example produces the following output:
five
four
three
two
one
Popping 'five'
Peek at next item to destack: four
Popping 'four'
Contents of the first copy:
one
two
three
Contents of the second copy, with duplicates and nulls:
one
two
three
stack2.Contains("four") = False
stack2.Clear()
stack2.Count = 0
*/
open System
open System.Collections.Generic
let numbers = Stack()
numbers.Push "one"
numbers.Push "two"
numbers.Push "three"
numbers.Push "four"
numbers.Push "five"
// A stack can be enumerated without disturbing its contents.
for number in numbers do
printfn $"{number}"
printfn $"\nPopping '{numbers.Pop()}'"
printfn $"Peek at next item to destack: {numbers.Peek()}"
numbers.Peek() |> ignore
printfn $"Popping '{numbers.Pop()}'"
// Create a copy of the stack, using the ToArray method and the
// constructor that accepts an IEnumerable<T>.
let stack2 = numbers.ToArray() |> Stack
printfn "\nContents of the first copy:"
for number in stack2 do
printfn $"{number}"
// Create an array twice the size of the stack and copy the
// elements of the stack, starting at the middle of the
// array.
let array2 = numbers.Count * 2 |> Array.zeroCreate
numbers.CopyTo(array2, numbers.Count)
// Create a second stack, using the constructor that accepts an
// IEnumerable(Of T).
let stack3 = Stack array2
printfn "\nContents of the second copy, with duplicates and nulls:"
for number in stack3 do
printfn $"{number}"
printfn
$"""
stack2.Contains "four" = {stack2.Contains "four"}"""
printfn "\nstack2.Clear()"
stack2.Clear()
printfn $"\nstack2.Count = {stack2.Count}"
// This code example produces the following output:
// five
// four
// three
// two
// one
//
// Popping 'five'
// Peek at next item to destack: four
// Popping 'four'
//
// Contents of the first copy:
// one
// two
// three
//
// Contents of the second copy, with duplicates and nulls:
// one
// two
// three
//
// stack2.Contains("four") = False
//
// stack2.Clear()
//
// stack2.Count = 0
Imports System.Collections.Generic
Module Example
Sub Main
Dim numbers As New Stack(Of String)
numbers.Push("one")
numbers.Push("two")
numbers.Push("three")
numbers.Push("four")
numbers.Push("five")
' A stack can be enumerated without disturbing its contents.
For Each number As String In numbers
Console.WriteLine(number)
Next
Console.WriteLine(vbLf & "Popping '{0}'", numbers.Pop())
Console.WriteLine("Peek at next item to pop: {0}", _
numbers.Peek())
Console.WriteLine("Popping '{0}'", numbers.Pop())
' Create another stack, using the ToArray method and the
' constructor that accepts an IEnumerable(Of T). Note that
' the order of items on the new stack is reversed.
Dim stack2 As New Stack(Of String)(numbers.ToArray())
Console.WriteLine(vbLf & "Contents of the first copy:")
For Each number As String In stack2
Console.WriteLine(number)
Next
' Create an array twice the size of the stack, compensating
' for the fact that Visual Basic allocates an extra array
' element. Copy the elements of the stack, starting at the
' middle of the array.
Dim array2((numbers.Count * 2) - 1) As String
numbers.CopyTo(array2, numbers.Count)
' Create a second stack, using the constructor that accepts an
' IEnumerable(Of T). The elements are reversed, with the null
' elements appearing at the end of the stack when enumerated.
Dim stack3 As New Stack(Of String)(array2)
Console.WriteLine(vbLf & _
"Contents of the second copy, with duplicates and nulls:")
For Each number As String In stack3
Console.WriteLine(number)
Next
Console.WriteLine(vbLf & "stack2.Contains(""four"") = {0}", _
stack2.Contains("four"))
Console.WriteLine(vbLf & "stack2.Clear()")
stack2.Clear()
Console.WriteLine(vbLf & "stack2.Count = {0}", _
stack2.Count)
End Sub
End Module
' This code example produces the following output:
'
'five
'four
'three
'two
'one
'
'Popping 'five'
'Peek at next item to pop: four
'Popping 'four'
'
'Contents of the first copy:
'one
'two
'three
'
'Contents of the second copy, with duplicates and nulls:
'one
'two
'three
'
'
'
'
'stack2.Contains("four") = False
'
'stack2.Clear()
'
'stack2.Count = 0
備註
元素會依後進先出的順序複製到陣列 (LIFO) 順序，類似於連續呼叫 Pop所傳回的項目順序。
這個方法是 O (n) 作業，其中 n 是 Count。
