ReadOnlyCollectionBase.Count プロパティ
ReadOnlyCollectionBase インスタンスに格納されている要素の数を取得します。
Public Overridable ReadOnly Property Count As Integer Implements _ ICollection.Count
[C#]
public virtual int Count {get;}
[C++]
public: __property virtual int get_Count();
[JScript]
public function get Count() : int;
プロパティ値
ReadOnlyCollectionBase インスタンスに格納されている要素の数。
実装
使用例
[Visual Basic, C#, C++] ReadOnlyCollectionBase クラスを実装するコード例を次に示します。
Imports System
Imports System.Collections
Public Class ROCollection
Inherits ReadOnlyCollectionBase
Public Sub New(sourceList As IList)
InnerList.AddRange(sourceList)
End Sub 'New
Default Public ReadOnly Property Item(index As Integer) As [Object]
Get
Return InnerList(index)
End Get
End Property
Public Function IndexOf(value As [Object]) As Integer
Return InnerList.IndexOf(value)
End Function 'IndexOf
Public Function Contains(value As [Object]) As Boolean
Return InnerList.Contains(value)
End Function 'Contains
End Class 'ROCollection
Public Class SamplesCollectionBase
Public Shared Sub Main()
' Create an ArrayList.
Dim myAL As New ArrayList()
myAL.Add("red")
myAL.Add("blue")
myAL.Add("yellow")
myAL.Add("green")
myAL.Add("orange")
myAL.Add("purple")
' Create a new ROCollection that contains the elements in myAL.
Dim myCol As New ROCollection(myAL)
' Display the contents of the collection using the enumerator.
Console.WriteLine("Contents of the collection (using enumerator):")
PrintIndexAndValues(myCol)
' Search the collection with Contains and IndexOf.
Console.WriteLine("Contains yellow: {0}", myCol.Contains("yellow"))
Console.WriteLine("orange is at index {0}.", myCol.IndexOf("orange"))
Console.WriteLine()
' Display the contents of the collection using the Count property and the Item property.
Console.WriteLine("Contents of the collection (using Count and Item):")
PrintIndexAndValues2(myCol)
End Sub 'Main
Public Shared Sub PrintIndexAndValues(myCol As ROCollection)
Dim i As Integer = 0
Dim myEnumerator As System.Collections.IEnumerator = myCol.GetEnumerator()
While myEnumerator.MoveNext()
Console.WriteLine(" [{0}]: {1}", i, myEnumerator.Current)
i += 1
End While
Console.WriteLine()
End Sub 'PrintIndexAndValues
Public Shared Sub PrintIndexAndValues2(myCol As ROCollection)
Dim i As Integer
For i = 0 To myCol.Count - 1
Console.WriteLine(" [{0}]: {1}", i, myCol(i))
Next i
Console.WriteLine()
End Sub 'PrintIndexAndValues2
End Class 'SamplesCollectionBase
'This code produces the following output.
'
'Contents of the collection (using enumerator):
' [0]: red
' [1]: blue
' [2]: yellow
' [3]: green
' [4]: orange
' [5]: purple
'
'Contains yellow: True
'orange is at index 4.
'
'Contents of the collection (using Count and Item):
' [0]: red
' [1]: blue
' [2]: yellow
' [3]: green
' [4]: orange
' [5]: purple
[C#]
using System;
using System.Collections;
public class ROCollection : ReadOnlyCollectionBase {
public ROCollection( IList sourceList ) {
InnerList.AddRange( sourceList );
}
public Object this[ int index ] {
get {
return( InnerList[index] );
}
}
public int IndexOf( Object value ) {
return( InnerList.IndexOf( value ) );
}
public bool Contains( Object value ) {
return( InnerList.Contains( value ) );
}
}
public class SamplesCollectionBase {
public static void Main() {
// Create an ArrayList.
ArrayList myAL = new ArrayList();
myAL.Add( "red" );
myAL.Add( "blue" );
myAL.Add( "yellow" );
myAL.Add( "green" );
myAL.Add( "orange" );
myAL.Add( "purple" );
// Create a new ROCollection that contains the elements in myAL.
ROCollection myCol = new ROCollection( myAL );
// Display the contents of the collection using the enumerator.
Console.WriteLine( "Contents of the collection (using enumerator):" );
PrintIndexAndValues( myCol );
// Search the collection with Contains and IndexOf.
Console.WriteLine( "Contains yellow: {0}", myCol.Contains( "yellow" ) );
Console.WriteLine( "orange is at index {0}.", myCol.IndexOf( "orange" ) );
Console.WriteLine();
// Display the contents of the collection using the Count property and the Item property.
Console.WriteLine( "Contents of the collection (using Count and Item):" );
PrintIndexAndValues2( myCol );
}
public static void PrintIndexAndValues( ROCollection myCol ) {
int i = 0;
System.Collections.IEnumerator myEnumerator = myCol.GetEnumerator();
while ( myEnumerator.MoveNext() )
Console.WriteLine( " [{0}]: {1}", i++, myEnumerator.Current );
Console.WriteLine();
}
public static void PrintIndexAndValues2( ROCollection myCol ) {
for ( int i = 0; i < myCol.Count; i++ )
Console.WriteLine( " [{0}]: {1}", i, myCol[i] );
Console.WriteLine();
}
}
/*
This code produces the following output.
Contents of the collection (using enumerator):
[0]: red
[1]: blue
[2]: yellow
[3]: green
[4]: orange
[5]: purple
Contains yellow: True
orange is at index 4.
Contents of the collection (using Count and Item):
[0]: red
[1]: blue
[2]: yellow
[3]: green
[4]: orange
[5]: purple
*/
[C++]
#using <mscorlib.dll>
using namespace System;
using namespace System::Collections;
public __gc class ROCollection : public ReadOnlyCollectionBase {
public:
ROCollection( IList* sourceList ) {
InnerList->AddRange( sourceList );
}
public:
__property Object* get_Item( int index ) {
return( InnerList->Item[index] );
}
public:
int IndexOf( Object* value ) {
return( InnerList->IndexOf( value ) );
}
public:
bool Contains( Object* value ) {
return( InnerList->Contains( value ) );
}
};
static void PrintIndexAndValues( ROCollection* myCol ) {
int i = 0;
System::Collections::IEnumerator* myEnumerator = myCol->GetEnumerator();
while ( myEnumerator->MoveNext() )
Console::WriteLine( S" [{0}]: {1}", __box(i++), myEnumerator->Current );
Console::WriteLine();
}
static void PrintIndexAndValues2( ROCollection* myCol ) {
for ( int i = 0; i < myCol->Count; i++ )
Console::WriteLine( S" [{0}]: {1}", __box(i), myCol->Item[i] );
Console::WriteLine();
}
int main() {
// Create an ArrayList.
ArrayList* myAL = new ArrayList();
myAL->Add( S"red" );
myAL->Add( S"blue" );
myAL->Add( S"yellow" );
myAL->Add( S"green" );
myAL->Add( S"orange" );
myAL->Add( S"purple" );
// Create a new ROCollection that contains the elements in myAL.
ROCollection* myCol = new ROCollection( myAL );
// Display the contents of the collection using the enumerator.
Console::WriteLine( S"Contents of the collection (using enumerator):" );
PrintIndexAndValues( myCol );
// Search the collection with Contains and IndexOf.
Console::WriteLine( S"Contains yellow: {0}", __box(myCol->Contains( S"yellow" )));
Console::WriteLine( S"orange is at index {0}.", __box(myCol->IndexOf( S"orange" )));
Console::WriteLine();
// Display the contents of the collection using the Count property and the Item property.
Console::WriteLine( S"Contents of the collection (using Count and Item):" );
PrintIndexAndValues2( myCol );
}
/*
This code produces the following output.
Contents of the collection (using enumerator):
[0]: red
[1]: blue
[2]: yellow
[3]: green
[4]: orange
[5]: purple
Contains yellow: True
orange is at index 4.
Contents of the collection (using Count and Item):
[0]: red
[1]: blue
[2]: yellow
[3]: green
[4]: orange
[5]: purple
*/
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必要条件
プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ
参照
ReadOnlyCollectionBase クラス | ReadOnlyCollectionBase メンバ | System.Collections 名前空間