NameObjectCollectionBase.BaseAdd(String, Object) 方法

定义

将具有指定键和值的项添加到 NameObjectCollectionBase 实例中。Adds an entry with the specified key and value into the NameObjectCollectionBase instance.

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)

参数

name
String

要添加的项的 String 键。The String key of the entry to add. 键可以是 nullThe key can be null.

value
Object

要添加的项的 Object 值。The Object value of the entry to add. 该值可以为 nullThe value can be null.

异常

集合为只读。The collection is read-only.

示例

下面的代码示例使用 BaseAdd 通过 IDictionary中的元素创建新 NameObjectCollectionBaseThe following code example uses BaseAdd to create a new NameObjectCollectionBase with elements from an IDictionary.

#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

注解

如果 Count 已经等于容量 NameObjectCollectionBase,则会自动重新分配内部数组,并将现有元素复制到新数组,然后再添加新元素。If Count already equals the capacity, the capacity of the NameObjectCollectionBase is increased by automatically reallocating the internal array, and the existing elements are copied to the new array before the new element is added.

如果 Count 小于容量,则此方法为 O (1)操作。If Count is less than the capacity, this method is an O(1) operation. 如果需要增加容量以容纳新元素,则此方法将成为 O (n)运算,CountnIf the capacity needs to be increased to accommodate the new element, this method becomes an O(n) operation, where n is Count.

适用于