NameObjectCollectionBase.BaseRemoveAt メソッド
NameObjectCollectionBase インスタンスの指定したインデックスにあるエントリを削除します。
Protected Sub BaseRemoveAt( _
ByVal index As Integer _)
[C#]
protected void BaseRemoveAt(intindex);
[C++]
protected: void BaseRemoveAt(intindex);
[JScript]
protected function BaseRemoveAt(
index : int);
パラメータ
- index
削除する要素の 0 から始まるインデックス。
例外
| 例外の種類 | 条件 |
|---|---|
| ArgumentOutOfRangeException | index が、コレクションのインデックスの有効範囲外です。 |
| NotSupportedException | コレクションが読み取り専用です。
または コレクションが固定サイズです。 |
解説
リストなどの連続する要素のコレクションでは、空白になった位置を埋めるために、削除された要素の後にある要素の位置が繰り上げられます。インデックス付きのコレクションの場合は、移動した要素のインデックスも更新されます。この動作は、要素が概念的にバケットにグループ化されているハッシュテーブルなどのコレクションには適用されません。
使用例
[Visual Basic, C#, C++] BaseRemove および BaseRemoveAt を使用して、すべての要素を NameObjectCollectionBase から削除する方法については、次のコード例を参照してください。
Imports System
Imports System.Collections
Imports System.Collections.Specialized
Public Class MyCollection
Inherits NameObjectCollectionBase
Private _de As New DictionaryEntry()
' Gets a key-and-value pair (DictionaryEntry) using an index.
Default Public ReadOnly Property Item(index As Integer) As DictionaryEntry
Get
_de.Key = Me.BaseGetKey(index)
_de.Value = Me.BaseGet(index)
Return _de
End Get
End Property
' Adds elements from an IDictionary into the new collection.
Public Sub New(d As IDictionary)
Dim de As DictionaryEntry
For Each de In d
Me.BaseAdd(CType(de.Key, [String]), de.Value)
Next de
End Sub 'New
' Removes an entry with the specified key from the collection.
Overloads Public Sub Remove(key As [String])
Me.BaseRemove(key)
End Sub 'Remove
' Removes an entry in the specified index from the collection.
Overloads Public Sub Remove(index As Integer)
Me.BaseRemoveAt(index)
End Sub 'Remove
End Class 'MyCollection
Public Class SamplesNameObjectCollectionBase
Public Shared Sub Main()
' Creates and initializes a new MyCollection instance.
Dim d = New ListDictionary()
d.Add("red", "apple")
d.Add("yellow", "banana")
d.Add("green", "pear")
Dim myCol As New MyCollection(d)
Console.WriteLine("Initial state of the collection (Count = {0}):", myCol.Count)
PrintKeysAndValues(myCol)
' Removes an element at a specific index.
myCol.Remove(1)
Console.WriteLine("After removing the element at index 1 (Count = {0}):", myCol.Count)
PrintKeysAndValues(myCol)
' Removes an element with a specific key.
myCol.Remove("red")
Console.WriteLine("After removing the element with the key ""red"" (Count = {0}):", myCol.Count)
PrintKeysAndValues(myCol)
End Sub 'Main
Public Shared Sub PrintKeysAndValues(myCol As MyCollection)
Dim i As Integer
For i = 0 To myCol.Count - 1
Console.WriteLine("[{0}] : {1}, {2}", i, myCol(i).Key, myCol(i).Value)
Next i
End Sub 'PrintKeysAndValues
End Class 'SamplesNameObjectCollectionBase
'This code produces the following output.
'
'Initial state of the collection (Count = 3):
'[0] : red, apple
'[1] : yellow, banana
'[2] : green, pear
'After removing the element at index 1 (Count = 2):
'[0] : red, apple
'[1] : green, pear
'After removing the element with the key "red" (Count = 1):
'[0] : green, pear
[C#]
using System;
using System.Collections;
using System.Collections.Specialized;
public class MyCollection : NameObjectCollectionBase {
private DictionaryEntry _de = new DictionaryEntry();
// Gets a key-and-value pair (DictionaryEntry) using an index.
public DictionaryEntry this[ int index ] {
get {
_de.Key = this.BaseGetKey( index );
_de.Value = this.BaseGet( index );
return( _de );
}
}
// Adds elements from an IDictionary into the new collection.
public MyCollection( IDictionary d ) {
foreach ( DictionaryEntry de in d ) {
this.BaseAdd( (String) de.Key, de.Value );
}
}
// Removes an entry with the specified key from the collection.
public void Remove( String key ) {
this.BaseRemove( key );
}
// Removes an entry in the specified index from the collection.
public void Remove( int index ) {
this.BaseRemoveAt( index );
}
}
public class SamplesNameObjectCollectionBase {
public static void Main() {
// Creates and initializes a new MyCollection instance.
IDictionary d = new ListDictionary();
d.Add( "red", "apple" );
d.Add( "yellow", "banana" );
d.Add( "green", "pear" );
MyCollection myCol = new MyCollection( d );
Console.WriteLine( "Initial state of the collection (Count = {0}):", myCol.Count );
PrintKeysAndValues( myCol );
// Removes an element at a specific index.
myCol.Remove( 1 );
Console.WriteLine( "After removing the element at index 1 (Count = {0}):", myCol.Count );
PrintKeysAndValues( myCol );
// Removes an element with a specific key.
myCol.Remove( "red" );
Console.WriteLine( "After removing the element with the key \"red\" (Count = {0}):", myCol.Count );
PrintKeysAndValues( myCol );
}
public static void PrintKeysAndValues( MyCollection myCol ) {
for ( int i = 0; i < myCol.Count; i++ ) {
Console.WriteLine( "[{0}] : {1}, {2}", i, myCol[i].Key, myCol[i].Value );
}
}
}
/*
This code produces the following output.
Initial state of the collection (Count = 3):
[0] : red, apple
[1] : yellow, banana
[2] : green, pear
After removing the element at index 1 (Count = 2):
[0] : red, apple
[1] : green, pear
After removing the element with the key "red" (Count = 1):
[0] : green, pear
*/
[C++]
#using <mscorlib.dll>
#using <system.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
public __gc class MyCollection : public NameObjectCollectionBase
{
private:
DictionaryEntry _de;
public:
// Gets a key-and-value pair (DictionaryEntry) using an index.
__property DictionaryEntry get_Item( int index )
{
_de.Key = this->BaseGetKey(index);
_de.Value = this->BaseGet(index);
return(_de);
}
// Adds elements from an IDictionary* into the new collection.
MyCollection(IDictionary* d)
{
IEnumerator* myEnum = d->GetEnumerator();
while (myEnum->MoveNext())
{
DictionaryEntry* de = __try_cast<DictionaryEntry*>(myEnum->Current);
this->BaseAdd(__try_cast<String*>(de->Key), de->Value);
}
}
// Removes an entry with the specified key from the collection.
void Remove(String* key)
{
this->BaseRemove(key);
}
// Removes an entry in the specified index from the collection.
void Remove(int index)
{
this->BaseRemoveAt(index);
}
};
void PrintKeysAndValues(MyCollection* myCol)
{
for (int i = 0; i < myCol->Count; i++)
{
Console::WriteLine(S"[{0}] : {1}, {2}", __box(i), myCol->Item[i].Key, myCol->Item[i].Value);
}
};
int main()
{
// Creates and initializes a new MyCollection instance.
IDictionary* d = new ListDictionary();
d->Add(S"red", S"apple");
d->Add(S"yellow", S"banana");
d->Add(S"green", S"pear");
MyCollection* myCol = new MyCollection(d);
Console::WriteLine(S"Initial state of the collection (Count = {0}):", __box(myCol->Count));
PrintKeysAndValues(myCol);
// Removes an element at a specific index.
myCol->Remove(1);
Console::WriteLine(S"After removing the element at index 1 (Count = {0}):", __box(myCol->Count));
PrintKeysAndValues(myCol);
// Removes an element with a specific key.
myCol->Remove(S"red");
Console::WriteLine(S"After removing the element with the key \"red\" (Count = {0}):", __box(myCol->Count));
PrintKeysAndValues(myCol);
}
/*
This code produces the following output.
Initial state of the collection (Count = 3):
[0] : red, apple
[1] : yellow, banana
[2] : green, pear
After removing the element at index 1 (Count = 2):
[0] : red, apple
[1] : green, pear
After removing the element with the key "red" (Count = 1):
[0] : green, pear
*/
[JScript] JScript のサンプルはありません。Visual Basic、C#、および C++ のサンプルを表示するには、このページの左上隅にある言語のフィルタ ボタン .gif)
をクリックします。
必要条件
プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ, .NET Compact Framework - Windows CE .NET
参照
NameObjectCollectionBase クラス | NameObjectCollectionBase メンバ | System.Collections.Specialized 名前空間