다음을 통해 공유


NameObjectCollectionBase.BaseGetKey(Int32) 메서드

정의

NameObjectCollectionBase 인스턴스의 지정한 인덱스에서 엔트리의 키를 가져옵니다.

protected:
 System::String ^ BaseGetKey(int index);
protected string BaseGetKey (int index);
protected string? BaseGetKey (int index);
member this.BaseGetKey : int -> string
Protected Function BaseGetKey (index As Integer) As String

매개 변수

index
Int32

가져올 키의 0부터 시작하는 인덱스입니다.

반환

지정한 인덱스에 있는 엔트리의 키를 나타내는 String입니다.

예외

index가 컬렉션의 유효한 인덱스 범위를 벗어납니다.

예제

다음 코드 예제에서는 및 BaseGet 를 사용하여 BaseGetKey 특정 키와 값을 가져옵니다.

#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 );
      }
   }

   // Gets or sets the value associated with the specified key.
   property Object^ default[ String^ ]  {
      Object^ get(String^ key)  {
         return( this->BaseGet( key ) );
      }
      void set( String^ key, Object^ value )  {
         this->BaseSet( key, value );
      }
   }

   // 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 );
      }
   }
};

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 );

      // Gets specific keys and values.
      Console::WriteLine( "The key at index 0 is {0}.", myCol[0]->Key );
      Console::WriteLine( "The value at index 0 is {0}.", myCol[0]->Value );
      Console::WriteLine( "The value associated with the key \"green\" is {0}.", myCol["green"] );

   }

   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
The key at index 0 is red.
The value at index 0 is apple.
The value associated with the key "green" is 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 );
      }
   }

   // Gets or sets the value associated with the specified key.
   public Object this[ String key ]  {
      get  {
         return( this.BaseGet( key ) );
      }
      set  {
         this.BaseSet( key, value );
      }
   }

   // 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 );
      Console.WriteLine( "Initial state of the collection (Count = {0}):", myCol.Count );
      PrintKeysAndValues( myCol );

      // Gets specific keys and values.
      Console.WriteLine( "The key at index 0 is {0}.", myCol[0].Key );
      Console.WriteLine( "The value at index 0 is {0}.", myCol[0].Value );
      Console.WriteLine( "The value associated with the key \"green\" is {0}.", myCol["green"] );
   }

   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
The key at index 0 is red.
The value at index 0 is apple.
The value associated with the key "green" is 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

   ' Gets or sets the value associated with the specified key.
   Default Public Property Item(key As [String]) As [Object]
      Get
         Return Me.BaseGet(key)
      End Get
      Set
         Me.BaseSet(key, value)
      End Set
   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)
      Console.WriteLine("Initial state of the collection (Count = {0}):", myCol.Count)
      PrintKeysAndValues(myCol)

      ' Gets specific keys and values.
      Console.WriteLine("The key at index 0 is {0}.", myCol(0).Key)
      Console.WriteLine("The value at index 0 is {0}.", myCol(0).Value)
      Console.WriteLine("The value associated with the key ""green"" is {0}.", myCol("green"))

   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
'The key at index 0 is red.
'The value at index 0 is apple.
'The value associated with the key "green" is pear.

설명

이 방법은 O(1) 작업에 설명 합니다.

적용 대상