ArrayList.GetRange(Int32, Int32) 方法
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
public:
virtual System::Collections::ArrayList ^ GetRange(int index, int count);public virtual System.Collections.ArrayList GetRange (int index, int count);abstract member GetRange : int * int -> System.Collections.ArrayList
override this.GetRange : int * int -> System.Collections.ArrayListPublic Overridable Function GetRange (index As Integer, count As Integer) As ArrayList参数
- count
- Int32
范围中的元素数。
返回
一个 ArrayList，它表示源 ArrayList 中的元素子集。
例外
index 和 count 不表示 ArrayList 中元素的有效范围。
示例
下面的代码示例演示如何设置和获取一 ArrayList系列元素。
using namespace System;
using namespace System::Collections;
void PrintValues( IEnumerable^ myList, char mySeparator );
int main()
{
// Creates and initializes a new ArrayList.
ArrayList^ myAL = gcnew ArrayList;
myAL->Add( "The" );
myAL->Add( "quick" );
myAL->Add( "brown" );
myAL->Add( "fox" );
myAL->Add( "jumps" );
myAL->Add( "over" );
myAL->Add( "the" );
myAL->Add( "lazy" );
myAL->Add( "dog" );
// Creates and initializes the source ICollection.
Queue^ mySourceList = gcnew Queue;
mySourceList->Enqueue( "big" );
mySourceList->Enqueue( "gray" );
mySourceList->Enqueue( "wolf" );
// Displays the values of five elements starting at index 0.
ArrayList^ mySubAL = myAL->GetRange( 0, 5 );
Console::WriteLine( "Index 0 through 4 contains:" );
PrintValues( mySubAL, '\t' );
// Replaces the values of five elements starting at index 1 with the values in the ICollection.
myAL->SetRange( 1, mySourceList );
// Displays the values of five elements starting at index 0.
mySubAL = myAL->GetRange( 0, 5 );
Console::WriteLine( "Index 0 through 4 now contains:" );
PrintValues( mySubAL, '\t' );
}
void PrintValues( IEnumerable^ myList, char mySeparator )
{
IEnumerator^ myEnum = myList->GetEnumerator();
while ( myEnum->MoveNext() )
{
Object^ obj = safe_cast<Object^>(myEnum->Current);
Console::Write( "{0}{1}", mySeparator, obj );
}
Console::WriteLine();
}
/*
This code produces the following output.
Index 0 through 4 contains:
The quick brown fox jumps
Index 0 through 4 now contains:
The big gray wolf jumps
*/
using System;
using System.Collections;
public class SamplesArrayList {
public static void Main() {
// Creates and initializes a new ArrayList.
ArrayList myAL = new ArrayList();
myAL.Add( "The" );
myAL.Add( "quick" );
myAL.Add( "brown" );
myAL.Add( "fox" );
myAL.Add( "jumps" );
myAL.Add( "over" );
myAL.Add( "the" );
myAL.Add( "lazy" );
myAL.Add( "dog" );
// Creates and initializes the source ICollection.
Queue mySourceList = new Queue();
mySourceList.Enqueue( "big" );
mySourceList.Enqueue( "gray" );
mySourceList.Enqueue( "wolf" );
// Displays the values of five elements starting at index 0.
ArrayList mySubAL = myAL.GetRange( 0, 5 );
Console.WriteLine( "Index 0 through 4 contains:" );
PrintValues( mySubAL, '\t' );
// Replaces the values of five elements starting at index 1 with the values in the ICollection.
myAL.SetRange( 1, mySourceList );
// Displays the values of five elements starting at index 0.
mySubAL = myAL.GetRange( 0, 5 );
Console.WriteLine( "Index 0 through 4 now contains:" );
PrintValues( mySubAL, '\t' );
}
public static void PrintValues( IEnumerable myList, char mySeparator ) {
foreach ( Object obj in myList )
Console.Write( "{0}{1}", mySeparator, obj );
Console.WriteLine();
}
}
/*
This code produces the following output.
Index 0 through 4 contains:
The quick brown fox jumps
Index 0 through 4 now contains:
The big gray wolf jumps
*/
Imports System.Collections
Public Class SamplesArrayList
Public Shared Sub Main()
' Creates and initializes a new ArrayList.
Dim myAL As New ArrayList()
myAL.Add("The")
myAL.Add("quick")
myAL.Add("brown")
myAL.Add("fox")
myAL.Add("jumps")
myAL.Add("over")
myAL.Add("the")
myAL.Add("lazy")
myAL.Add("dog")
' Creates and initializes the source ICollection.
Dim mySourceList As New Queue()
mySourceList.Enqueue("big")
mySourceList.Enqueue("gray")
mySourceList.Enqueue("wolf")
' Displays the values of five elements starting at index 0.
Dim mySubAL As ArrayList = myAL.GetRange(0, 5)
Console.WriteLine("Index 0 through 4 contains:")
PrintValues(mySubAL, vbTab)
' Replaces the values of five elements starting at index 1 with the values in the ICollection.
myAL.SetRange(1, mySourceList)
' Displays the values of five elements starting at index 0.
mySubAL = myAL.GetRange(0, 5)
Console.WriteLine("Index 0 through 4 now contains:")
PrintValues(mySubAL, vbTab)
End Sub
Public Shared Sub PrintValues(myList As IEnumerable, mySeparator As Char)
Dim obj As [Object]
For Each obj In myList
Console.Write("{0}{1}", mySeparator, obj)
Next obj
Console.WriteLine()
End Sub
End Class
' This code produces the following output.
'
' Index 0 through 4 contains:
' The quick brown fox jumps
' Index 0 through 4 now contains:
' The big gray wolf jumps
注解
此方法不创建元素的副本。 ArrayList新项只是源ArrayList中的视图窗口。 但是，必须通过此视图窗口ArrayList完成对源ArrayList的所有后续更改。 如果直接对源 ArrayList进行更改，视图窗口 ArrayList 将失效，并且对它执行的任何操作都将返回一个 InvalidOperationException。
此方法是一种 O(1) 操作。