NameObjectCollectionBase.BaseRemove(String) 方法
定义
移除 NameObjectCollectionBase 实例中具有指定键的项。Removes the entries with the specified key from the NameObjectCollectionBase instance.
protected:
void BaseRemove(System::String ^ name);
protected void BaseRemove (string name);
member this.BaseRemove : string -> unit
Protected Sub BaseRemove (name As String)
参数
例外
该集合是只读的。The collection is read-only.
示例
下面的代码示例使用 BaseRemove 和 BaseRemoveAt 从中移除元素 NameObjectCollectionBase 。The following code example uses BaseRemove and BaseRemoveAt to remove elements from a NameObjectCollectionBase.
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
public ref class MyCollection : public NameObjectCollectionBase {
private:
DictionaryEntry^ _de;
// Gets a key-and-value pair (DictionaryEntry) using an index.
public:
property DictionaryEntry^ default[ int ] {
DictionaryEntry^ get(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 ) {
_de = gcnew DictionaryEntry();
for each ( DictionaryEntry^ de in d ) {
this->BaseAdd( (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 );
}
};
public ref class SamplesNameObjectCollectionBase {
public:
static void Main() {
// Creates and initializes a new MyCollection instance.
IDictionary^ d = gcnew ListDictionary();
d->Add( "red", "apple" );
d->Add( "yellow", "banana" );
d->Add( "green", "pear" );
MyCollection^ myCol = gcnew 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 );
}
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 );
}
}
};
int main()
{
SamplesNameObjectCollectionBase::Main();
}
/*
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
*/
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
*/
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
' Removes an entry with the specified key from the collection.
Overloads Public Sub Remove(key As [String])
Me.BaseRemove(key)
End Sub
' Removes an entry in the specified index from the collection.
Overloads Public Sub Remove(index As Integer)
Me.BaseRemoveAt(index)
End Sub
End Class
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
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
End Class
'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
注解
如果不 NameObjectCollectionBase 包含具有指定键的元素,则将 NameObjectCollectionBase 保持不变。If the NameObjectCollectionBase does not contain an element with the specified key, the NameObjectCollectionBase remains unchanged. 不会引发异常。No exception is thrown.
在由连续的元素组成的集合(如列表)中,已移除元素下面的元素将上移以占据空出的位置。In collections of contiguous elements, such as lists, the elements that follow the removed element move up to occupy the vacated spot. 如果集合具有索引,则移动的元素的索引也将更新。If the collection is indexed, the indexes of the elements that are moved are also updated. 此行为不适用于元素按概念划分为不同存储桶的集合,如哈希表。This behavior does not apply to collections where elements are conceptually grouped into buckets, such as a hash table.
此方法是 O (n
) 操作,其中 n
是 Count 。This method is an O(n
) operation, where n
is Count.