ArrayList.GetRange(Int32, Int32) Method
Definition
Important
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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 ArrayListParameters
- count
- Int32
The number of elements in the range.
Returns
An ArrayList which represents a subset of the elements in the source ArrayList.
Exceptions
index and count do not denote a valid range of elements in the ArrayList.
Examples
The following code example shows how to set and get a range of elements in the ArrayList.
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
Remarks
This method does not create copies of the elements. The new ArrayList is only a view window into the source ArrayList. However, all subsequent changes to the source ArrayList must be done through this view window ArrayList. If changes are made directly to the source ArrayList, the view window ArrayList is invalidated and any operations on it will return an InvalidOperationException.
This method is an O(1) operation.
Applies to
See also
Dolgozzon együtt velünk a GitHubon
A tartalom forrása a GitHubon található, ahol létrehozhat és áttekinthet problémákat és lekéréses kérelmeket is. További információért tekintse meg a közreműködői útmutatónkat.
