NameObjectCollectionBase.BaseAdd(String, Object) 方法

定義

命名空間:

System.Collections.Specialized

組件:

System.Collections.Specialized.dll

來源:

NameObjectCollectionBase.cs

將具有指定索引鍵和值的項目加入 NameObjectCollectionBase 執行個體。

protected:
 void BaseAdd(System::String ^ name, System::Object ^ value);

protected void BaseAdd (string? name, object? value);

member this.BaseAdd : string * obj -> unit

Protected Sub BaseAdd (name As String, value As Object)

參數

name

String

要加入之項目的 String 索引鍵。 這個索引鍵可以是 null。

value

Object

要加入之項目的 Object 值。 這個值可以是 null。

例外狀況

NotSupportedException

集合是唯讀的。

範例

下列程式代碼範例會使用 BaseAdd 從 建立具有 專案IDictionary的新 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;

public:

   property DictionaryEntry Item [ int ]
   {
      // Gets a key-and-value pair (DictionaryEntry) using an index.
      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 )
   {
      IEnumerator^ myEnum = d->GetEnumerator();
      while ( myEnum->MoveNext() )
      {
         DictionaryEntry^ de = safe_cast<DictionaryEntry^>(myEnum->Current);
         this->BaseAdd( safe_cast<String^>(de->Key), de->Value );
      }
   }
};

int 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 );

   // Displays the keys and values of the MyCollection instance.
   for ( int i = 0; i < myCol->Count; i++ )
   {
      Console::WriteLine( "[{0}] : {1}, {2}", i, myCol->Item[ i ].Key, myCol->Item[ i ].Value );
   }
}

/*
This code produces the following output.

[0] : red, apple
[1] : yellow, banana
[2] : 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 );
      }
   }
}

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 );

      // Displays the keys and values of the MyCollection instance.
      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.

[0] : red, apple
[1] : yellow, banana
[2] : 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

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)

      ' Displays the keys and values of the MyCollection instance.
      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.
'
'[0] : red, apple
'[1] : yellow, banana
'[2] : green, pear

備註

如果 Count 已經等於容量，則會藉由自動重新配置內部數位來增加的 NameObjectCollectionBase 容量，而現有的元素會在新增專案之前複製到新的陣列。

如果 Count 小於容量，則這個方法是 O (1) 作業。 如果需要增加容量以容納新的元素，這個方法會變成 O () n 作業，其中 n 是 Count。