StringDictionary.ContainsKey メソッド

.NET Framework クラス ライブラリ リファレンス

StringDictionary.ContainsKey メソッド

StringDictionary に特定のキーが格納されているかどうかを確認します。

名前空間: System.Collections.Specialized
アセンブリ: System (system.dll 内)
構文

Visual Basic (宣言)

Public Overridable Function
 ContainsKey ( _
    key As String _
) As Boolean

Visual Basic (使用法)

Dim instance As StringDictionary
Dim key As String
Dim returnValue As Boolean

returnValue = instance.ContainsKey(key)

C#

public virtual bool ContainsKey (
    string key
)

C++

public:
virtual bool ContainsKey (
    String^ key
)

J#

public boolean ContainsKey (
    String key
)

JScript

public function ContainsKey (
    key : String
) : boolean

パラメータ

key

StringDictionary 内で検索されるキー。

戻り値
指定したキーを持つエントリが StringDictionary に格納されている場合は true。それ以外の場合は false。

例外

例外の種類	条件
ArgumentNullException	キーが null 参照 (Visual Basic では Nothing) です。

解説

キーは大文字と小文字を区別せずに処理されます。つまり、キーは使用される前に小文字に変換されます。

このメソッドは O(1) 操作です。

使用例

StringDictionary の要素を検索する例を次に示します。

Visual Basic

Imports System
Imports System.Collections
Imports System.Collections.Specialized

Public Class SamplesStringDictionary   

   Public Shared Sub Main()

      ' Creates and initializes a new StringDictionary.
      Dim myCol As New StringDictionary()
      myCol.Add("red", "rojo")
      myCol.Add("green", "verde")
      myCol.Add("blue", "azul")

      ' Displays the values in the StringDictionary.
      Console.WriteLine("Initial contents of the StringDictionary:")
      PrintKeysAndValues(myCol)

      ' Searches for a key.
      If myCol.ContainsKey("red")
 Then
         Console.WriteLine("The collection contains the key ""red"".")
      Else
         Console.WriteLine("The collection does not contain the
 key ""red"".")
      End If
      Console.WriteLine()

      ' Searches for a value.
      If myCol.ContainsValue("amarillo")
 Then
         Console.WriteLine("The collection contains the value
 ""amarillo"".")
      Else
         Console.WriteLine("The collection does not contain the
 value ""amarillo"".")
      End If
      Console.WriteLine()

   End Sub 'Main

   Public Shared Sub PrintKeysAndValues(myCol
 As StringDictionary)
      Dim de As DictionaryEntry

      Console.WriteLine("   KEY        VALUE")
      For Each de In  myCol
         Console.WriteLine("   {0,-10} {1}", de.Key,
 de.Value)
      Next de
      Console.WriteLine()

   End Sub 'PrintKeysAndValues

End Class 'SamplesStringDictionary
 


'This code produces the following output.
'
'Initial contents of the StringDictionary:
'   KEY        VALUE
'   green      verde
'   red        rojo
'   blue       azul
'
'The collection contains the key "red".
'
'The collection does not contain the value "amarillo".

C#

using System;
using System.Collections;
using System.Collections.Specialized;

public class SamplesStringDictionary  {

   public static void Main()
  {

      // Creates and initializes a new StringDictionary.
      StringDictionary myCol = new StringDictionary();
      myCol.Add( "red", "rojo" );
      myCol.Add( "green", "verde" );
      myCol.Add( "blue", "azul" );

      // Displays the values in the StringDictionary.
      Console.WriteLine( "Initial contents of the StringDictionary:" );
      PrintKeysAndValues( myCol );

      // Searches for a key.
      if ( myCol.ContainsKey( "red" ) )
         Console.WriteLine( "The collection contains the key \"red\"."
 );
      else
         Console.WriteLine( "The collection does not contain the key \"red\"."
 );
      Console.WriteLine();

      // Searches for a value.
      if ( myCol.ContainsValue( "amarillo" ) )
         Console.WriteLine( "The collection contains the value \"amarillo\"."
 );
      else
         Console.WriteLine( "The collection does not contain the value \"amarillo\"."
 );
      Console.WriteLine();

   }

   public static void PrintKeysAndValues(
 StringDictionary myCol )  {
      Console.WriteLine( "   KEY        VALUE" );
      foreach ( DictionaryEntry de in myCol
 )
         Console.WriteLine( "   {0,-10} {1}", de.Key, de.Value );
      Console.WriteLine();
   }

}

/*
This code produces the following output.

Initial contents of the StringDictionary:
   KEY        VALUE
   green      verde
   red        rojo
   blue       azul

The collection contains the key "red".

The collection does not contain the value "amarillo".

*/

C++

#using <System.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
void PrintKeysAndValues( StringDictionary^ myCol )
{
   Console::WriteLine( "   KEY        VALUE" );
   IEnumerator^ enum0 = myCol->GetEnumerator();
   while ( enum0->MoveNext() )
   {
      DictionaryEntry^ de = safe_cast<DictionaryEntry^>(enum0->Current);
      Console::WriteLine( "   {0,-10} {1}", de->Key, de->Value );
   }

   Console::WriteLine();
}

int main()
{
   
   // Creates and initializes a new StringDictionary.
   StringDictionary^ myCol = gcnew StringDictionary;
   myCol->Add( "red", "rojo" );
   myCol->Add( "green", "verde" );
   myCol->Add( "blue", "azul" );
   
   // Displays the values in the StringDictionary.
   Console::WriteLine( "Initial contents of the StringDictionary:" );
   PrintKeysAndValues( myCol );
   
   // Searches for a key.
   if ( myCol->ContainsKey( "red" ) )
      Console::WriteLine( "The collection contains the key \"red\"."
 );
   else
      Console::WriteLine( "The collection does not contain the key \"red\"."
 );

   Console::WriteLine();
   
   // Searches for a value.
   if ( myCol->ContainsValue( "amarillo" ) )
      Console::WriteLine( "The collection contains the value \"amarillo\"."
 );
   else
      Console::WriteLine( "The collection does not contain the value \"amarillo\"."
 );

   Console::WriteLine();
}

/*
This code produces the following output.

Initial contents of the StringDictionary:
   KEY        VALUE
   green      verde
   red        rojo
   blue       azul

The collection contains the key "red".

The collection does not contain the value "amarillo".

*/

J#

import System.*;
import System.Collections.*;
import System.Collections.Specialized.*;

public class SamplesStringDictionary
{
    public static void main(String[]
 args)
    {
        // Creates and initializes a new StringDictionary.
        StringDictionary myCol =  new StringDictionary();
        myCol.Add("red", "rojo");
        myCol.Add("green", "verde");
        myCol.Add("blue", "azul");
          
        // Displays the values in the StringDictionary.
        Console.WriteLine("Initial contents of the StringDictionary:");
        PrintKeysAndValues(myCol);
          
        // Searches for a key.
        if ( myCol.ContainsKey("red")  ) {
            Console.WriteLine("The collection contains the key \"red\".");
        }
        else {
            Console.WriteLine("The collection does not contain the key "
                + "\"red\".");
        }
        Console.WriteLine();
          
        // Searches for a value.
        if ( myCol.ContainsValue("amarillo")  ) {
            Console.WriteLine("The collection contains the value " 
                + "\"amarillo\".");
        }
        else {
            Console.WriteLine("The collection does not contain the value"+
                " \"amarillo\".");
        }
        Console.WriteLine();
    } //main
        
    public static void PrintKeysAndValues(StringDictionary
 myCol) 
    {
        Console.WriteLine("   KEY        VALUE");
        IEnumerator objEnum = myCol.GetEnumerator();
        while (objEnum.MoveNext()) {
            DictionaryEntry de = (DictionaryEntry)objEnum.get_Current();
            Console.WriteLine("   {0,-10} {1}", de.get_Key(), de.get_Value());
        }
        Console.WriteLine();
    } //PrintKeysAndValues
} //SamplesStringDictionary
 
/*
This code produces the following output.

Initial contents of the StringDictionary:
   KEY        VALUE
   red        rojo
   blue       azul
   green      verde

The collection contains the key "red".

The collection does not contain the value "amarillo".

*/

プラットフォーム

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0、1.1、1.0
.NET Compact Framework
サポート対象 : 2.0

参照

関連項目
StringDictionary クラス
StringDictionary メンバ
System.Collections.Specialized 名前空間
その他の技術情報
カルチャを認識しない文字列操作の実行