通过

StringCollection.CopyTo 方法

  • 项目

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。

**命名空间:**System.Collections.Specialized
**程序集:**System（在 system.dll 中）

语法

声明
Public Sub CopyTo ( _
    array As String(), _
    index As Integer _
)
用法
Dim instance As StringCollection
Dim array As String()
Dim index As Integer

instance.CopyTo(array, index)

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

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

public void CopyTo (
    String[] array, 
    int index
)

public function CopyTo (
    array : String[], 
    index : int
)

参数

  • array
    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
    array 中从零开始的索引，从此处开始复制。

异常

异常类型 条件

ArgumentNullException

array 为 空引用（在 Visual Basic 中为 Nothing）。

ArgumentOutOfRangeException

index 小于零。

ArgumentException

array 是多维的。

- 或 -

index 等于或大于 array 的长度。

- 或 -

源 StringCollection 中的元素数目大于从 index 到目标 array 末尾之间的可用空间。

InvalidCastException

源 StringCollection 的类型无法自动转换为目标 array 的类型。

备注

指定的数组必须是兼容类型的数组。

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

此方法的运算复杂度为 O(n)，其中 n 是 Count。

示例

下面的代码示例将 StringCollection 复制到数组。

Imports System
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 'Main

   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 'PrintValues

End Class 'SamplesStringCollection 


'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

*/

#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

*/

import System.* ;
import System.Collections.* ;
import System.Collections.Specialized.* ;

public class SamplesStringCollection
{    
    public static void main(String[] args)
    {        
        // 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.get_Count()];
        myCol.CopyTo(myArr2, 0);
        
        Console.WriteLine("The new array contains:");
        for (int i=0; i < myArr2.length; i++) {        
            Console.WriteLine("   [{0}] {1}",System.Convert.ToString(i),
                myArr2.get_Item(i));
        } 
        Console.WriteLine();
    } //main

    public static void PrintValues(IEnumerable myCol)
    {
        Object obj = null;
        IEnumerator objEnum = myCol.GetEnumerator();

        while (objEnum.MoveNext()) {        
            obj = objEnum.get_Current();
            Console.WriteLine("   {0}", obj);
        }

        Console.WriteLine();
    } //PrintValues
} //SamplesStringCollection 

/*
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

*/

平台

Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

请参见

参考

StringCollection 类
StringCollection 成员
System.Collections.Specialized 命名空间
Array 类
GetEnumerator