ListDictionary.Contains メソッド
ListDictionary に特定のキーが格納されているかどうかを判断します。
名前空間: System.Collections.Specialized
アセンブリ: System (system.dll 内)
構文
'宣言
Public Function Contains ( _
key As Object _
) As Boolean
'使用
Dim instance As ListDictionary
Dim key As Object
Dim returnValue As Boolean
returnValue = instance.Contains(key)
public bool Contains (
Object key
)
public:
virtual bool Contains (
Object^ key
) sealed
public final boolean Contains (
Object key
)
public final function Contains (
key : Object
) : boolean
パラメータ
- key
ListDictionary 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 ListDictionary 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 |
|---|---|
key が null 参照 (Visual Basic では Nothing) です。 |
解説
このメソッドは O(n) 操作です。ここで、n は Count です。
使用例
ListDictionary の要素を検索する例を次に示します。
Imports System
Imports System.Collections
Imports System.Collections.Specialized
Public Class SamplesListDictionary
Public Shared Sub Main()
' Creates and initializes a new ListDictionary.
Dim myCol As New ListDictionary()
myCol.Add("Braeburn Apples", "1.49")
myCol.Add("Fuji Apples", "1.29")
myCol.Add("Gala Apples", "1.49")
myCol.Add("Golden Delicious Apples", "1.29")
myCol.Add("Granny Smith Apples", "0.89")
myCol.Add("Red Delicious Apples", "0.99")
' Displays the values in the ListDictionary in three different ways.
Console.WriteLine("Initial contents of the ListDictionary:")
PrintKeysAndValues(myCol)
' Searches for a key.
If myCol.Contains("Kiwis") Then
Console.WriteLine("The collection contains the key ""Kiwis"".")
Else
Console.WriteLine("The collection does not contain the key ""Kiwis"".")
End If
Console.WriteLine()
End Sub 'Main
Public Shared Sub PrintKeysAndValues(myCol As IDictionary)
Console.WriteLine(" KEY VALUE")
Dim de As DictionaryEntry
For Each de In myCol
Console.WriteLine(" {0,-25} {1}", de.Key, de.Value)
Next de
Console.WriteLine()
End Sub 'PrintKeysAndValues
End Class 'SamplesListDictionary
'This code produces the following output.
'
'Initial contents of the ListDictionary:
' KEY VALUE
' Braeburn Apples 1.49
' Fuji Apples 1.29
' Gala Apples 1.49
' Golden Delicious Apples 1.29
' Granny Smith Apples 0.89
' Red Delicious Apples 0.99
'
'The collection does not contain the key "Kiwis".
using System;
using System.Collections;
using System.Collections.Specialized;
public class SamplesListDictionary {
public static void Main() {
// Creates and initializes a new ListDictionary.
ListDictionary myCol = new ListDictionary();
myCol.Add( "Braeburn Apples", "1.49" );
myCol.Add( "Fuji Apples", "1.29" );
myCol.Add( "Gala Apples", "1.49" );
myCol.Add( "Golden Delicious Apples", "1.29" );
myCol.Add( "Granny Smith Apples", "0.89" );
myCol.Add( "Red Delicious Apples", "0.99" );
// Displays the values in the ListDictionary in three different ways.
Console.WriteLine( "Initial contents of the ListDictionary:" );
PrintKeysAndValues( myCol );
// Searches for a key.
if ( myCol.Contains( "Kiwis" ) )
Console.WriteLine( "The collection contains the key \"Kiwis\"." );
else
Console.WriteLine( "The collection does not contain the key \"Kiwis\"." );
Console.WriteLine();
}
public static void PrintKeysAndValues( IDictionary myCol ) {
Console.WriteLine( " KEY VALUE" );
foreach ( DictionaryEntry de in myCol )
Console.WriteLine( " {0,-25} {1}", de.Key, de.Value );
Console.WriteLine();
}
}
/*
This code produces the following output.
Initial contents of the ListDictionary:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
The collection does not contain the key "Kiwis".
*/
#using <System.dll>
using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
void PrintKeysAndValues( IDictionary^ myCol )
{
Console::WriteLine( " KEY VALUE" );
IEnumerator^ myEnum = myCol->GetEnumerator();
while ( myEnum->MoveNext() )
{
DictionaryEntry de = safe_cast<DictionaryEntry>(myEnum->Current);
Console::WriteLine( " {0,-25} {1}", de.Key, de.Value );
}
Console::WriteLine();
}
int main()
{
// Creates and initializes a new ListDictionary.
ListDictionary^ myCol = gcnew ListDictionary;
myCol->Add( "Braeburn Apples", "1.49" );
myCol->Add( "Fuji Apples", "1.29" );
myCol->Add( "Gala Apples", "1.49" );
myCol->Add( "Golden Delicious Apples", "1.29" );
myCol->Add( "Granny Smith Apples", "0.89" );
myCol->Add( "Red Delicious Apples", "0.99" );
// Displays the values in the ListDictionary in three different ways.
Console::WriteLine( "Initial contents of the ListDictionary:" );
PrintKeysAndValues( myCol );
// Searches for a key.
if ( myCol->Contains( "Kiwis" ) )
Console::WriteLine( "The collection contains the key \"Kiwis\"." );
else
Console::WriteLine( "The collection does not contain the key \"Kiwis\"." );
Console::WriteLine();
}
/*
This code produces the following output.
Initial contents of the ListDictionary:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
The collection does not contain the key "Kiwis".
*/
import System.*;
import System.Collections.*;
import System.Collections.Specialized.*;
public class SamplesListDictionary
{
public static void main(String[] args)
{
// Creates and initializes a new ListDictionary.
ListDictionary myCol = new ListDictionary();
myCol.Add("Braeburn Apples", "1.49");
myCol.Add("Fuji Apples", "1.29");
myCol.Add("Gala Apples", "1.49");
myCol.Add("Golden Delicious Apples", "1.29");
myCol.Add("Granny Smith Apples", "0.89");
myCol.Add("Red Delicious Apples", "0.99");
// Displays the values in the ListDictionary in three different ways.
Console.WriteLine("Initial contents of the ListDictionary:");
PrintKeysAndValues(myCol);
// Searches for a key.
if (myCol.Contains("Kiwis")) {
Console.WriteLine("The collection contains the key \"Kiwis\".");
}
else {
Console.WriteLine("The collection does not contain the key "
+ "\"Kiwis\".");
}
Console.WriteLine();
} //main
public static void PrintKeysAndValues(IDictionary myCol)
{
IEnumerator objEnum = myCol.GetEnumerator();
Console.WriteLine(" KEY VALUE");
while (objEnum.MoveNext()) {
DictionaryEntry de = (DictionaryEntry)objEnum.get_Current();
Console.WriteLine(" {0,-25} {1}", de.get_Key(), de.get_Value());
}
Console.WriteLine();
} //PrintKeysAndValues
} //SamplesListDictionary
/*
This code produces the following output.
Initial contents of the ListDictionary:
KEY VALUE
Braeburn Apples 1.49
Fuji Apples 1.29
Gala Apples 1.49
Golden Delicious Apples 1.29
Granny Smith Apples 0.89
Red Delicious Apples 0.99
The collection does not contain the key "Kiwis".
*/
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、1.0
参照
関連項目
ListDictionary クラス
ListDictionary メンバ
System.Collections.Specialized 名前空間
IDictionary インターフェイス